Advanced configuration

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To change the behavior of GitLab Runner and individual registered runners, modify the config.toml file.

You can find the config.toml file in:

  • /etc/gitlab-runner/ on *nix systems when GitLab Runner is executed as root. This directory is also the path for service configuration.
  • ~/.gitlab-runner/ on *nix systems when GitLab Runner is executed as non-root.
  • ./ on other systems.

GitLab Runner does not require a restart when you change most options. This includes parameters in the [[runners]] section and most parameters in the global section, except for listen_address. If a runner was already registered, you don’t need to register it again.

GitLab Runner checks for configuration modifications every 3 seconds and reloads if necessary. GitLab Runner also reloads the configuration in response to the SIGHUP signal.

Configuration validation

History

Configuration validation is a process that checks the structure of the config.toml file. The output from the configuration validator provides only info level messages.

The configuration validation process is for informational purposes only. You can use the output to to identify potential issues with your runner configuration. The configuration validation might not catch all possible problems, and the absence of messages does not guarantee that the config.toml file is flawless.

The global section

These settings are global. They apply to all runners.

Setting Description
concurrent Limits how many jobs can run concurrently, across all registered runners. Each [[runners]] section can define its own limit, but this value sets a maximum for all of those values combined. For example, a value of 10 means no more than 10 jobs can run concurrently. 0 is forbidden. If you use this value, the runner process exits with a critical error. View how this setting works with the Docker Machine executor (for autoscaling).
log_level Defines the log level. Options are debug, info, warn, error, fatal, and panic. This setting has lower priority than the level set by the command-line arguments --debug, -l, or --log-level.
log_format Specifies the log format. Options are runner, text, and json. This setting has lower priority than the format set by command-line argument --log-format. The default value is runner, which contains ANSI escape codes for coloring.
check_interval Defines the interval length, in seconds, between the runner checking for new jobs. The default value is 3. If set to 0 or lower, the default value is used.
sentry_dsn Enables tracking of all system level errors to Sentry.
connection_max_age The maximum duration a TLS keepalive connection to the GitLab server should remain open before reconnecting. The default value is 15m for 15 minutes. If set to 0 or lower, the connection will persist as long as possible.
listen_address Defines an address (<host>:<port>) the Prometheus metrics HTTP server should listen on.
shutdown_timeout Number of seconds until the forceful shutdown operation times out and exits the process. The default value is 30. If set to 0 or lower, the default value is used.

Configuration example:

concurrent = 4
log_level = "warning"

log_format examples (truncated)

runner

Runtime platform                                    arch=amd64 os=darwin pid=37300 revision=HEAD version=development version
Starting multi-runner from /etc/gitlab-runner/config.toml...  builds=0
WARNING: Running in user-mode.
WARNING: Use sudo for system-mode:
WARNING: $ sudo gitlab-runner...

Configuration loaded                                builds=0
listen_address not defined, metrics & debug endpoints disabled  builds=0
[session_server].listen_address not defined, session endpoints disabled  builds=0

text

INFO[0000] Runtime platform                              arch=amd64 os=darwin pid=37773 revision=HEAD version="development version"
INFO[0000] Starting multi-runner from /etc/gitlab-runner/config.toml...  builds=0
WARN[0000] Running in user-mode.
WARN[0000] Use sudo for system-mode:
WARN[0000] $ sudo gitlab-runner...
INFO[0000]
INFO[0000] Configuration loaded                          builds=0
INFO[0000] listen_address not defined, metrics & debug endpoints disabled  builds=0
INFO[0000] [session_server].listen_address not defined, session endpoints disabled  builds=0

json

{"arch":"amd64","level":"info","msg":"Runtime platform","os":"darwin","pid":38229,"revision":"HEAD","time":"2020-06-05T15:57:35+02:00","version":"development version"}
{"builds":0,"level":"info","msg":"Starting multi-runner from /etc/gitlab-runner/config.toml...","time":"2020-06-05T15:57:35+02:00"}
{"level":"warning","msg":"Running in user-mode.","time":"2020-06-05T15:57:35+02:00"}
{"level":"warning","msg":"Use sudo for system-mode:","time":"2020-06-05T15:57:35+02:00"}
{"level":"warning","msg":"$ sudo gitlab-runner...","time":"2020-06-05T15:57:35+02:00"}
{"level":"info","msg":"","time":"2020-06-05T15:57:35+02:00"}
{"builds":0,"level":"info","msg":"Configuration loaded","time":"2020-06-05T15:57:35+02:00"}
{"builds":0,"level":"info","msg":"listen_address not defined, metrics \u0026 debug endpoints disabled","time":"2020-06-05T15:57:35+02:00"}
{"builds":0,"level":"info","msg":"[session_server].listen_address not defined, session endpoints disabled","time":"2020-06-05T15:57:35+02:00"}

How check_interval works

If config.toml has more than one [[runners]] section, GitLab Runner contains a loop that constantly schedules job requests to the GitLab instance where GitLab Runner is configured.

The following example has check_interval of 10 seconds and two [[runners]] sections (runner-1 and runner-2). GitLab Runner sends a request every 10 seconds and sleeps for five seconds:

  1. Get check_interval value (10s).
  2. Get list of runners (runner-1, runner-2).
  3. Calculate the sleep interval (10s / 2 = 5s).
  4. Start an infinite loop:
    1. Request a job for runner-1.
    2. Sleep for 5s.
    3. Request a job for runner-2.
    4. Sleep for 5s.
    5. Repeat.

In this example, a job request from the runner’s process is made every five seconds. If runner-1 and runner-2 are connected to the same GitLab instance, this GitLab instance also receives a new request from this runner every five seconds.

Two sleep periods occur between the first and second requests for runner-1. Each period takes five seconds, so it’s approximately 10 seconds between subsequent requests for runner-1. The same applies for runner-2.

If you define more runners, the sleep interval is smaller. However, a request for a runner is repeated after all requests for the other runners and their sleep periods are called.

The [session_server] section

The [session_server] section lets users interact with jobs, for example, in the interactive web terminal.

The [session_server] section should be specified at the root level, not per runner. It should be defined outside the [[runners]] section.

[session_server]
  listen_address = "[::]:8093" #  listen on all available interfaces on port 8093
  advertise_address = "runner-host-name.tld:8093"
  session_timeout = 1800

When you configure the [session_server] section:

  • For listen_address and advertise_address, use the format host:port, where host is the IP address (127.0.0.1:8093) or domain (my-runner.example.com:8093). The runner uses this information to create a TLS certificate for a secure connection.
  • Ensure your web browser can connect to the advertise_address. Live sessions are initiated by the web browser.
  • Ensure that advertise_address is a public IP address, unless you have enabled the application setting, allow_local_requests_from_web_hooks_and_services.
Setting Description
listen_address An internal URL for the session server.
advertise_address The URL to access the session server. GitLab Runner exposes it to GitLab. If not defined, listen_address is used.
session_timeout Number of seconds the session can stay active after the job completes. The timeout blocks the job from finishing. Default is 1800 (30 minutes).

To disable the session server and terminal support, delete the [session_server] section.

note
When your runner instance is already running, you might need to execute gitlab-runner restart for the changes in the [session_server] section to be take effect.

If you are using the GitLab Runner Docker image, you must expose port 8093 by adding -p 8093:8093 to your docker run command.

The [[runners]] section

Each [[runners]] section defines one runner.

Setting Description
name The runner’s description. Informational only.
url GitLab instance URL.
token The runner’s authentication token, which is obtained during runner registration. Not the same as the registration token.
tls-ca-file When using HTTPS, file that contains the certificates to verify the peer. See Self-signed certificates or custom Certification Authorities documentation.
tls-cert-file When using HTTPS, file that contains the certificate to authenticate with the peer.
tls-key-file When using HTTPS, file that contains the private key to authenticate with the peer.
limit Limit how many jobs can be handled concurrently by this registered runner. 0 (default) means do not limit. View how this setting works with the Docker Machine executor (for autoscaling).
executor Select how a project should be built.
shell Name of shell to generate the script. Default value is platform dependent.
builds_dir Absolute path to a directory where builds are stored in the context of the selected executor. For example, locally, Docker, or SSH.
cache_dir Absolute path to a directory where build caches are stored in context of selected executor. For example, locally, Docker, or SSH. If the docker executor is used, this directory needs to be included in its volumes parameter.
environment Append or overwrite environment variables.
request_concurrency Limit number of concurrent requests for new jobs from GitLab. Default is 1.
output_limit Maximum build log size in kilobytes. Default is 4096 (4MB).
pre_get_sources_script Commands to be executed on the runner before updating the Git repository and updating submodules. Use it to adjust the Git client configuration first, for example. To insert multiple commands, use a (triple-quoted) multi-line string or \n character.
post_get_sources_script Commands to be executed on the runner after updating the Git repository and updating submodules. To insert multiple commands, use a (triple-quoted) multi-line string or \n character.
pre_build_script Commands to be executed on the runner before executing the job. To insert multiple commands, use a (triple-quoted) multi-line string or \n character.
post_build_script Commands to be executed on the runner just after executing the job, but before executing after_script. To insert multiple commands, use a (triple-quoted) multi-line string or \n character.
clone_url Overwrite the URL for the GitLab instance. Used only if the runner can’t connect to the GitLab URL.
debug_trace_disabled Disables the CI_DEBUG_TRACE feature. When set to true, then debug log (trace) remains disabled, even if CI_DEBUG_TRACE is set to true by the user.
referees Extra job monitoring workers that pass their results as job artifacts to GitLab.
unhealthy_requests_limit The number of unhealthy responses to new job requests after which a runner worker will be disabled.
unhealthy_interval Duration that a runner worker is disabled for after it exceeds the unhealthy requests limit. Supports syntax like ‘3600s’, ‘1h30min’ etc.

Example:

[[runners]]
  name = "ruby-2.7-docker"
  url = "https://CI/"
  token = "TOKEN"
  limit = 0
  executor = "docker"
  builds_dir = ""
  shell = ""
  environment = ["ENV=value", "LC_ALL=en_US.UTF-8"]
  clone_url = "http://gitlab.example.local"

How clone_url works

When the GitLab instance is available at a URL that the runner can’t use, you can configure a clone_url.

For example, a firewall might prevent the runner from reaching the URL. If the runner can reach the node on 192.168.1.23, set the clone_url to http://192.168.1.23.

If the clone_url is set, the runner constructs a clone URL in the form of http://gitlab-ci-token:s3cr3tt0k3n@192.168.1.23/namespace/project.git.

How unhealthy_requests_limit and unhealthy_interval works

When a GitLab instance is unavailable for an extended period of time (for example, during a version upgrade), the runners configured for that instance become idle and do not resume job processing for 30-60 minutes after the GitLab instance is available again.

To increase or decrease the duration that runners are idle, change the unhealthy_interval setting.

To change the number of times the runner attempts to connect to the GitLab server and receive an unhealthy sleep before becoming idle, change the unhealthy_requests_limit setting. For more information, see How check_interval works.

The executors

The following executors are available.

Executor Required configuration Where jobs run
shell   Local shell. The default executor.
docker [runners.docker] and Docker Engine A Docker container.
docker-windows [runners.docker] and Docker Engine A Windows Docker container.
ssh [runners.ssh] SSH, remotely.
parallels [runners.parallels] and [runners.ssh] Parallels VM, but connect with SSH.
virtualbox [runners.virtualbox] and [runners.ssh] VirtualBox VM, but connect with SSH.
docker+machine [runners.docker] and [runners.machine] Like docker, but use auto-scaled Docker machines.
kubernetes [runners.kubernetes] Kubernetes pods.

The shells

The available shells can run on different platforms.

Shell Description
bash Generate Bash (Bourne-shell) script. All commands executed in Bash context. Default for all Unix systems.
sh Generate Sh (Bourne-shell) script. All commands executed in Sh context. The fallback for bash for all Unix systems.
powershell Generate PowerShell script. All commands are executed in PowerShell Desktop context. In GitLab Runner 12.0-13.12, this is the default for Windows.
pwsh Generate PowerShell script. All commands are executed in PowerShell Core context. In GitLab Runner 14.0 and later, this is the default for Windows.

When the shell option is set to bash or sh, Bash’s ANSI-C quoting is used to shell escape job scripts.

Use a POSIX-compliant shell

In GitLab Runner 14.9 and later, enable the feature flag named FF_POSIXLY_CORRECT_ESCAPES to use a POSIX-compliant shell (like dash). When enabled, “Double Quotes”, which is POSIX-compliant shell escaping mechanism, is used.

The [runners.docker] section

The following settings define the Docker container parameters.

Docker-in-Docker as a service, or any container runtime configured inside a job, does not inherit these parameters.

Parameter Description
allowed_images Wildcard list of images that can be specified in the .gitlab-ci.yml file. If not present, all images are allowed (equivalent to ["*/*:*"]). Use with the Docker or Kubernetes executors.
allowed_privileged_images Wildcard subset of allowed_images that runs in privileged mode when privileged is enabled. If not present, all images are allowed (equivalent to ["*/*:*"]). Use with the Docker executors.
allowed_pull_policies List of pull policies that can be specified in the .gitlab-ci.yml file or the config.toml file. If not specified, all pull policies specified in pull-policy are allowed. Use with the Docker executor.
allowed_services Wildcard list of services that can be specified in the .gitlab-ci.yml file. If not present, all images are allowed (equivalent to ["*/*:*"]). Use with the Docker or Kubernetes executors.
allowed_privileged_services Wildcard subset of allowed_services that is allowed to run in privileged mode, when privileged or services_privileged is enabled. If not present, all images are allowed (equivalent to ["*/*:*"]). Use with the Docker executors.
cache_dir Directory where Docker caches should be stored. This path can be absolute or relative to current working directory. See disable_cache for more information.
cap_add Add additional Linux capabilities to the container.
cap_drop Drop additional Linux capabilities from the container.
cpuset_cpus The control group’s CpusetCpus. A string.
cpuset_mems The control group’s CpusetMems. A string.
cpu_shares Number of CPU shares used to set relative CPU usage. Default is 1024.
cpus Number of CPUs (available in Docker 1.13 or later). A string.
devices Share additional host devices with the container.
device_cgroup_rules Custom device cgroup rules (available in Docker 1.28 or later).
disable_cache The Docker executor has two levels of caching: a global one (like any other executor) and a local cache based on Docker volumes. This configuration flag acts only on the local one which disables the use of automatically created (not mapped to a host directory) cache volumes. In other words, it only prevents creating a container that holds temporary files of builds, it does not disable the cache if the runner is configured in distributed cache mode.
disable_entrypoint_overwrite Disable the image entrypoint overwriting.
dns A list of DNS servers for the container to use.
dns_search A list of DNS search domains.
extra_hosts Hosts that should be defined in container environment.
gpus GPU devices for Docker container. Uses the same format as the docker cli. View details in the Docker documentation.
group_add Add additional groups the container process will run as.
helper_image (Advanced) The default helper image used to clone repositories and upload artifacts.
helper_image_flavor Sets the helper image flavor (alpine, alpine3.16, alpine3.17, alpine3.18, alpine3.19, alpine-latest, ubi-fips or ubuntu). Defaults to alpine. The alpine flavor uses the same version as alpine3.18.
helper_image_autoset_arch_and_os Uses the underlying OS to set the Helper Image ARCH and OS.
host Custom Docker endpoint. Default is DOCKER_HOST environment or unix:///var/run/docker.sock.
hostname Custom hostname for the Docker container.
image The image to run jobs with.
links Containers that should be linked with container that runs the job.
memory The memory limit. A string.
memory_swap The total memory limit. A string.
memory_reservation The memory soft limit. A string.
network_mode Add container to a custom network.
mac_address Container MAC address (e.g., 92:d0:c6:0a:29:33).
oom_kill_disable If an out-of-memory (OOM) error occurs, do not kill processes in a container.
oom_score_adjust OOM score adjustment. Positive means kill earlier.
privileged Make the container run in privileged mode. Insecure.
services_privileged Allow services to run in privileged mode. If unset (default) privileged value is used instead. Use with the Docker executor. Insecure.
pull_policy The image pull policy: never, if-not-present or always (default). View details in the pull policies documentation. You can also add multiple pull policies, retry a failed pull, or restrict pull policies.
runtime The runtime for the Docker container.
isolation Container isolation technology (default, hyperv and process). Windows only.
security_opt Security options (–security-opt in docker run). Takes a list of : separated key/values.
shm_size Shared memory size for images (in bytes).
sysctls The sysctl options.
tls_cert_path A directory where ca.pem, cert.pem or key.pem are stored and used to make a secure TLS connection to Docker. Useful in boot2docker.
tls_verify Enable or disable TLS verification of connections to Docker daemon. Disabled by default.
user Run all commands in the container as the specified user.
userns_mode The user namespace mode for the container and Docker services when user namespace remapping option is enabled. Available in Docker 1.10 or later.
ulimit Ulimit values that are passed to the container. Uses the same syntax as the Docker --ulimit flag.
volumes Additional volumes that should be mounted. Same syntax as the Docker -v flag.
volumes_from A list of volumes to inherit from another container in the form <container name>[:<access_level>]. Access level defaults to read-write, but can be manually set to ro (read-only) or rw (read-write).
volume_driver The volume driver to use for the container.
wait_for_services_timeout How long to wait for Docker services. Set to -1 to disable. Default is 30.
container_labels A set of labels to add to each container created by the runner. The label value can include environment variables for expansion.
services_limit Set the maximum allowed services per job. -1 (default) means there is no limit.
service_cpuset_cpus String value containing the cgroups CpusetCpus to use for a service.
service_cpu_shares Number of CPU shares used to set a service’s relative cpu usage (default: 1024).
service_cpus String value of the number of CPUs for a service. Available in Docker 1.13 or later.
service_memory String value of the memory limit for a service.
service_memory_swap String value of the total memory limit for a service.
service_memory_reservation String value of the memory soft limit for a service.

The [[runners.docker.services]] section

Specify additional services to run with the job. For a list of available images, see the Docker Registry. Each service runs in a separate container and is linked to the job.

Parameter Description
name The name of the image to be run as a service.
alias Additional alias name that can be used to access the service .
entrypoint Command or script that should be executed as the container’s entrypoint. The syntax is similar to Dockerfile’s ENTRYPOINT directive, where each shell token is a separate string in the array. Introduced in GitLab Runner 13.6.
command Command or script that should be used as the container’s command. The syntax is similar to Dockerfile’s CMD directive, where each shell token is a separate string in the array. Introduced in GitLab Runner 13.6.
environment Append or overwrite environment variables for the service container.

Example:

[runners.docker]
  host = ""
  hostname = ""
  tls_cert_path = "/Users/ayufan/.boot2docker/certs"
  image = "ruby:2.7"
  memory = "128m"
  memory_swap = "256m"
  memory_reservation = "64m"
  oom_kill_disable = false
  cpuset_cpus = "0,1"
  cpuset_mems = "0,1"
  cpus = "2"
  dns = ["8.8.8.8"]
  dns_search = [""]
  service_memory = "128m"
  service_memory_swap = "256m"
  service_memory_reservation = "64m"
  service_cpuset_cpus = "0,1"
  service_cpus = "2"
  services_limit = 5
  privileged = false
  group_add = ["docker"]
  userns_mode = "host"
  cap_add = ["NET_ADMIN"]
  cap_drop = ["DAC_OVERRIDE"]
  devices = ["/dev/net/tun"]
  disable_cache = false
  wait_for_services_timeout = 30
  cache_dir = ""
  volumes = ["/data", "/home/project/cache"]
  extra_hosts = ["other-host:127.0.0.1"]
  shm_size = 300000
  volumes_from = ["storage_container:ro"]
  links = ["mysql_container:mysql"]
  allowed_images = ["ruby:*", "python:*", "php:*"]
  allowed_services = ["postgres:9", "redis:*", "mysql:*"]
  [runners.docker.ulimit]
    "rtprio" = "99"
  [[runners.docker.services]]
    name = "registry.example.com/svc1"
    alias = "svc1"
    entrypoint = ["entrypoint.sh"]
    command = ["executable","param1","param2"]
    environment = ["ENV1=value1", "ENV2=value2"]
  [[runners.docker.services]]
    name = "redis:2.8"
    alias = "cache"
  [[runners.docker.services]]
    name = "postgres:9"
    alias = "postgres-db"
  [runners.docker.sysctls]
    "net.ipv4.ip_forward" = "1"

Volumes in the [runners.docker] section

For more information about volumes, see the Docker documentation.

The following examples show how to specify volumes in the [runners.docker] section.

Example 1: Add a data volume

A data volume is a specially-designated directory in one or more containers that bypasses the Union File System. Data volumes are designed to persist data, independent of the container’s life cycle.

[runners.docker]
  host = ""
  hostname = ""
  tls_cert_path = "/Users/ayufan/.boot2docker/certs"
  image = "ruby:2.7"
  privileged = false
  disable_cache = true
  volumes = ["/path/to/volume/in/container"]

This example creates a new volume in the container at /path/to/volume/in/container.

Example 2: Mount a host directory as a data volume

When you want to store directories outside the container, you can mount a directory from your Docker daemon’s host into a container:

[runners.docker]
  host = ""
  hostname = ""
  tls_cert_path = "/Users/ayufan/.boot2docker/certs"
  image = "ruby:2.7"
  privileged = false
  disable_cache = true
  volumes = ["/path/to/bind/from/host:/path/to/bind/in/container:rw"]

This example uses /path/to/bind/from/host of the CI/CD host in the container at /path/to/bind/in/container.

GitLab Runner 11.11 and later mount the host directory for the defined services as well.

Use a private container registry

To use private registries as a source of images for your jobs, configure authorization with the CI/CD variable DOCKER_AUTH_CONFIG. You can set the variable in one of the following:

  • The CI/CD settings of the project as the file type
  • The config.toml file

Using private registries with the if-not-present pull policy may introduce security implications. For more information about how pull policies work, see Configure how runners pull images.

For more information about using private container registries, see:

The steps performed by the runner can be summed up as:

  1. The registry name is found from the image name.
  2. If the value is not empty, the executor searches for the authentication configuration for this registry.
  3. Finally, if an authentication corresponding to the specified registry is found, subsequent pulls makes use of it.

Support for GitLab integrated registry

GitLab sends credentials for its integrated registry along with the job’s data. These credentials are automatically added to the registry’s authorization parameters list.

After this step, authorization against the registry proceeds similarly to configuration added with the DOCKER_AUTH_CONFIG variable.

In your jobs, you can use any image from your GitLab integrated registry, even if the image is private or protected. For information on the images jobs have access to, read the CI/CD job token documentation documentation.

Precedence of Docker authorization resolving

As described earlier, GitLab Runner can authorize Docker against a registry by using credentials sent in different way. To find a proper registry, the following precedence is taken into account:

  1. Credentials configured with DOCKER_AUTH_CONFIG.
  2. Credentials configured locally on the GitLab Runner host with ~/.docker/config.json or ~/.dockercfg files (for example, by running docker login on the host).
  3. Credentials sent by default with a job’s payload (for example, credentials for the integrated registry described earlier).

The first credentials found for the registry are used. So for example, if you add credentials for the integrated registry with the DOCKER_AUTH_CONFIG variable, then the default credentials are overridden.

The [runners.parallels] section

The following parameters are for Parallels.

Parameter Description
base_name Name of Parallels VM that is cloned.
template_name Custom name of Parallels VM linked template. Optional.
disable_snapshots If disabled, the VMs are destroyed when the jobs are done.
allowed_images List of allowed image/base_name values, represented as regular expressions. See the Overriding the base VM image section for more details.

Example:

[runners.parallels]
  base_name = "my-parallels-image"
  template_name = ""
  disable_snapshots = false

The [runners.virtualbox] section

The following parameters are for VirtualBox. This executor relies on the vboxmanage executable to control VirtualBox machines, so you have to adjust your PATH environment variable on Windows hosts: PATH=%PATH%;C:\Program Files\Oracle\VirtualBox.

Parameter Explanation
base_name Name of the VirtualBox VM that is cloned.
base_snapshot Name or UUID of a specific snapshot of the VM to create a linked clone from. If this value is empty or omitted, the current snapshot is used. If no current snapshot exists, one is created. Unless disable_snapshots is true, in which case a full clone of the base VM is made.
base_folder Folder to save the new VM in. If this value is empty or omitted, the default VM folder is used.
disable_snapshots If disabled, the VMs are destroyed when the jobs are done.
allowed_images List of allowed image/base_name values, represented as regular expressions. See the Overriding the base VM image section for more details.
start_type Graphical front-end type when starting the VM.

Example:

[runners.virtualbox]
  base_name = "my-virtualbox-image"
  base_snapshot = "my-image-snapshot"
  disable_snapshots = false
  start_type = "headless"

The start_type parameter determines the graphical front end used when starting the virtual image. Valid values are headless (default), gui or separate as supported by the host and guest combination.

Overriding the base VM image

History
  • Introduced in GitLab Runner 14.2.

For both the Parallels and VirtualBox executors, you can override the base VM name specified by base_name. To do this, use the image parameter in the .gitlab-ci.yml file.

For backward compatibility, you cannot override this value by default. Only the image specified by base_name is allowed.

To allow users to select a VM image by using the .gitlab-ci.yml image parameter:

[runners.virtualbox]
  ...
  allowed_images = [".*"]

In the example, any existing VM image can be used.

The allowed_images parameter is a list of regular expressions. Configuration can be as precise as required. For instance, if you want to allow only certain VM images, you can use regex like:

[runners.virtualbox]
  ...
  allowed_images = ["^allowed_vm[1-2]$"]

In this example, only allowed_vm1 and allowed_vm2 are allowed. Any other attempts will result in an error.

The [runners.ssh] section

The following parameters define the SSH connection.

Parameter Description
host Where to connect.
port Port. Default is 22.
user Username.
password Password.
identity_file File path to SSH private key (id_rsa, id_dsa, or id_edcsa). The file must be stored unencrypted.
disable_strict_host_key_checking This value determines if the runner should use strict host key checking. Default is true. In GitLab 15.0, the default value, or the value if it’s not specified, will be false.

Example:

[runners.ssh]
  host = "my-production-server"
  port = "22"
  user = "root"
  password = "production-server-password"
  identity_file = ""

The [runners.machine] section

The following parameters define the Docker Machine-based autoscaling feature. For more information, see Docker Machine Executor autoscale configuration.

Parameter Description
MaxGrowthRate The maximum number of machines that can be added to the runner in parallel. Default is 0 (no limit).
IdleCount Number of machines that need to be created and waiting in Idle state.
IdleScaleFactor (Experiment) The number of Idle machines as a factor of the number of machines in use. Must be in float number format. See the autoscale documentation for more details. Defaults to 0.0.
IdleCountMin Minimal number of machines that need to be created and waiting in Idle state when the IdleScaleFactor is in use. Default is 1.
IdleTime Time (in seconds) for machine to be in Idle state before it is removed.
[[runners.machine.autoscaling]] Multiple sections, each containing overrides for autoscaling configuration. The last section with an expression that matches the current time is selected.
OffPeakPeriods Deprecated: Time periods when the scheduler is in the OffPeak mode. An array of cron-style patterns (described below).
OffPeakTimezone Deprecated: Timezone for the times given in OffPeakPeriods. A timezone string like Europe/Berlin. Defaults to the locale system setting of the host if omitted or empty. GitLab Runner attempts to locate the timezone database in the directory or uncompressed zip file named by the ZONEINFO environment variable, then looks in known installation locations on Unix systems, and finally looks in $GOROOT/lib/time/zoneinfo.zip.
OffPeakIdleCount Deprecated: Like IdleCount, but for Off Peak time periods.
OffPeakIdleTime Deprecated: Like IdleTime, but for Off Peak time periods.
MaxBuilds Maximum job (build) count before machine is removed.
MachineName Name of the machine. It must contain %s, which is replaced with a unique machine identifier.
MachineDriver Docker Machine driver. View details in the Cloud Providers Section in the Docker Machine configuration.
MachineOptions Docker Machine options for the MachineDriver. For more information, see Supported Cloud Providers. For more information about all options for AWS, see the AWS and GCP projects in the Docker Machine repository.

The [[runners.machine.autoscaling]] sections

Parameter Description
Periods Time periods during which this schedule is active. An array of cron-style patterns (described below).
IdleCount Number of machines that need to be created and waiting in Idle state.
IdleScaleFactor (Experiment) The number of Idle machines as a factor of the number of machines in use. Must be in float number format. See the autoscale documentation for more details. Defaults to 0.0.
IdleCountMin Minimal number of machines that need to be created and waiting in Idle state when the IdleScaleFactor is in use. Default is 1.
IdleTime Time (in seconds) for a machine to be in Idle state before it is removed.
Timezone Timezone for the times given in Periods. A timezone string like Europe/Berlin. Defaults to the locale system setting of the host if omitted or empty. GitLab Runner attempts to locate the timezone database in the directory or uncompressed zip file named by the ZONEINFO environment variable, then looks in known installation locations on Unix systems, and finally looks in $GOROOT/lib/time/zoneinfo.zip.

Example:

[runners.machine]
  IdleCount = 5
  IdleTime = 600
  MaxBuilds = 100
  MachineName = "auto-scale-%s"
  MachineDriver = "google" # Refer to Docker Machine docs on how to authenticate: https://docs.docker.com/machine/drivers/gce/#credentials
  MachineOptions = [
      # Additional machine options can be added using the Google Compute Engine driver.
      # If you experience problems with an unreachable host (ex. "Waiting for SSH"),
      # you should remove optional parameters to help with debugging.
      # https://docs.docker.com/machine/drivers/gce/
      "google-project=GOOGLE-PROJECT-ID",
      "google-zone=GOOGLE-ZONE", # e.g. 'us-central1-a', full list in https://cloud.google.com/compute/docs/regions-zones/
  ]
  [[runners.machine.autoscaling]]
    Periods = ["* * 9-17 * * mon-fri *"]
    IdleCount = 50
    IdleCountMin = 5
    IdleScaleFactor = 1.5 # Means that current number of Idle machines will be 1.5*in-use machines,
                          # no more than 50 (the value of IdleCount) and no less than 5 (the value of IdleCountMin)
    IdleTime = 3600
    Timezone = "UTC"
  [[runners.machine.autoscaling]]
    Periods = ["* * * * * sat,sun *"]
    IdleCount = 5
    IdleTime = 60
    Timezone = "UTC"

Periods syntax

The Periods setting contains an array of string patterns of time periods represented in a cron-style format. The line contains following fields:

[second] [minute] [hour] [day of month] [month] [day of week] [year]

Like in the standard cron configuration file, the fields can contain single values, ranges, lists, and asterisks. View a detailed description of the syntax.

The [runners.instance] section

Status: Beta

The following parameters define the configuration for the instance executor. The instance executor is in beta

Parameter Type Description
allowed_images string When VM Isolation is enabled, allowed_images controls which images a job is allowed to specify.

The [runners.autoscaler] section

History
  • Introduced in GitLab Runner v15.10.0.

The following parameters configure the autoscaler feature. You can only use these parameters with the Instance and Docker Autoscaler executors. These executors are in beta.

Parameter Description
capacity_per_instance The number of jobs that can be executed concurrently by a single instance.
max_use_count The maximum number of times an instance can be used before it is scheduled for removal.
max_instances The maximum number of instances that are allowed, this is regardless of the instance state (pending, running, deleting). Default: 0 (unlimited).
plugin The fleeting plugin to use. For more information about how to install and reference a plugin, see Install the fleeting plugin.
delete_instances_on_shutdown Specifies if all provision instances are deleted when GitLab Runner is shutting down. Default: false. Introduced in GitLab Runner 15.11
instance_ready_command Executes this command on each instance provisioned by the autoscaler to ensure that it is ready for use. A failure results in the instance being removed. Introduced in GitLab Runner 16.11.
update_interval The interval to check with the fleeting plugin for instance updates. Default: 1m (1 minute). Introduced in GitLab Runner 16.11.
update_interval_when_expecting The interval to check with the fleeting plugin for instance updates when expecting a state change. For example, when an instance has provisioned an instance and the runner is waiting to transition from pending to running). Default: 2s (2 seconds). Introduced in GitLab Runner 16.11.
note
If the instance_ready_command frequently fails with idle scale rules, instances might be removed and created faster than the runner accepts jobs. To support scale throttling, an exponential backoff was added in GitLab 17.0.

The [runners.autoscaler.plugin_config] section

This hash table is re-encoded to JSON and passed directly to the configured plugin.

fleeting plugins typically have accompanying documentation on the supported configuration.

The [runners.autoscaler.scale_throttle] section

History
  • Introduced in GitLab Runner v17.0.0.
Parameter Description
limit The rate limit of new instances per second that can provisioned. -1 is infinite. The default (0), sets the limit to 100.
burst The burst limit of new instances. Defaults to max_instances or limit when max_instances is not set. If limit is infinite, burst is ignored.

The [runners.autoscaler.connector_config] section

fleeting plugins typically have accompanying documentation on the supported connection options.

Plugins automatically update the connector configuration. You can use the [runners.autoscaler.connector_config] to override automatic update of the connector configuration, or to fill in the empty values that the plugin cannot determine.

Parameter Description
os The operating system of the instance.
arch The architecture of the instance.
protocol The protocol to use: ssh or winrm.
username The username used to connect with.
password The password used to connect with.
key_path The TLS key used to connect with or dynamically provision credentials with.
use_static_credentials Disabled automatic credential provisioning. Default: false.
keepalive The connection keepalive duration.
timeout The connection timeout duration.
use_external_addr Whether to use the external address provided by the plugin. If the plugin only returns an internal address, this will be used regardless of this setting. Default: false.

The [[runners.autoscaler.policy]] sections

Note - idle_count in this context refers to the number of jobs, not the number of autoscaled machines as in the legacy autoscaling method.

periods An array of unix-cron formatted strings to denote the period this policy is enabled for. Default: * * * * *
timezone The timezone used when evaluating the unix-cron period. Default: The system’s local timezone.
idle_count The target idle capacity we want to be immediately available for jobs.
idle_time The amount of time that an instance can be idle before it is terminated.
scale_factor The target idle capacity we want to be immediately available for jobs, on top of the idle_count, as a factor of the current in use capacity. Defaults to 0.0.
scale_factor_limit The maximum capacity the scale_factor calculation can yield.

When scale_factor is set, idle_count becomes the minimum idle capacity and the scaler_factor_limit the maximum idle capacity.

You can define multiple policies. The last matching policy is the one used.

In the following example, the idle count 1 is used between 08:00 and 15:59, Monday through Friday. Otherwise, the idle count is 0.

[[runners.autoscaler.policy]]
  idle_count        = 1
  idle_time         = "30m0s"
  periods           = ["* 8-15 * * mon-fri"]

[[runners.autoscaler.policy]]
  idle_count        = 0
  idle_time         = "0s"
  periods           = ["* * * * *"]

Periods syntax

The periods setting contains an array of unix-cron formatted strings to denote the period a policy is enabled for. The cron format consists of 5 fields:

 ┌────────── minute (0 - 59)
 │ ┌──────── hour (0 - 23)
 │ │ ┌────── day of month (1 - 31)
 │ │ │ ┌──── month (1 - 12)
 │ │ │ │ ┌── day of week (1 - 7 or MON-SUN, 0 is an alias for Sunday)
 * * * * *
  • - can be used between two numbers to specify a range.
  • * can be used to represent the whole range of valid values for that field.
  • / followed by a number or can be used after a range to skip that number through the range. For example, 0-12/2 for the hour field would activate the period every 2 hours between the hours of 00:00 and 00:12.
  • , can be used to separate a list of valid numbers or ranges for the field. For example, 1,2,6-9.

It’s worth keeping in mind that this cron job represents a range in time. For example:

Period Affect
1 * * * * * Rule enabled for the period of 1 minute every hour (unlikely to be very useful)
* 0-12 * * * Rule enabled for the period of 12 hours at the beginning of each day
0-30 13,16 * * SUN Rule enabled for the period of each Sunday for 30 minutes at 1pm and 30 minutes at 4pm.

The [runners.autoscaler.vm_isolation] section

VM Isolation uses nesting, which is currently only supported on MacOS.

Parameter Description
enabled Specifies if VM Isolation is enabled or not. Default: false.
nesting_host The nesting daemon host.
nesting_config The nesting config. This is serialized to JSON and sent to the nesting daemon.
image The default image used by the nesting daemon if no job image is specified.

The [runners.autoscaler.vm_isolation.connector_config] section

The parameters for the [runners.autoscaler.vm_isolation.connector_config] section are identical to the [runners.autoscaler.connector_config] section, but are used to connect to the nesting provisioned virtual machine, rather than the autoscaled instance.

The [runners.custom] section

The following parameters define configuration for the custom executor.

Parameter Type Description
config_exec string Path to an executable, so a user can override some configuration settings before the job starts. These values override the ones set in the [[runners]] section. The custom executor documentation has the full list.
config_args string array First set of arguments passed to the config_exec executable.
config_exec_timeout integer Timeout, in seconds, for config_exec to finish execution. Default is 3600 seconds (1 hour).
prepare_exec string Path to an executable to prepare the environment.
prepare_args string array First set of arguments passed to the prepare_exec executable.
prepare_exec_timeout integer Timeout, in seconds, for prepare_exec to finish execution. Default is 3600 seconds (1 hour).
run_exec string Required. Path to an executable to run scripts in the environments. For example, the clone and build script.
run_args string array First set of arguments passed to the run_exec executable.
cleanup_exec string Path to an executable to clean up the environment.
cleanup_args string array First set of arguments passed to the cleanup_exec executable.
cleanup_exec_timeout integer Timeout, in seconds, for cleanup_exec to finish execution. Default is 3600 seconds (1 hour).
graceful_kill_timeout integer Time to wait, in seconds, for prepare_exec and cleanup_exec if they are terminated (for example, during job cancellation). After this timeout, the process is killed. Default is 600 seconds (10 minutes).
force_kill_timeout integer Time to wait, in seconds, after the kill signal is sent to the script. Default is 600 seconds (10 minutes).

The [runners.cache] section

The following parameters define the distributed cache feature. View details in the runner autoscale documentation.

Parameter Type Description
Type string One of: s3, gcs, azure.
Path string Name of the path to prepend to the cache URL.
Shared boolean Enables cache sharing between runners. Default is false.
MaxUploadedArchiveSize int64 Limit, in bytes, of the cache archive being uploaded to cloud storage. A malicious actor can work around this limit so the GCS adapter enforces it through the X-Goog-Content-Length-Range header in the signed URL. You should also set the limit on your cloud storage provider.

The cache mechanism uses pre-signed URLs to upload and download cache. URLs are signed by GitLab Runner on its own instance. It does not matter if the job’s script (including the cache upload/download script) are executed on local or external machines. For example, shell or docker executors run their scripts on the same machine where the GitLab Runner process is running. At the same time, virtualbox or docker+machine connects to a separate VM to execute the script. This process is for security reasons: minimizing the possibility of leaking the cache adapter’s credentials.

If the S3 cache adapter is configured to use an IAM instance profile, the adapter uses the profile attached to the GitLab Runner machine. Similarly for GCS cache adapter, if configured to use the CredentialsFile. The file needs to be present on the GitLab Runner machine.

This table lists config.toml, CLI options, and ENV variables for register.

Setting TOML field CLI option for register ENV for register
Type [runners.cache] -> Type --cache-type $CACHE_TYPE
Path [runners.cache] -> Path --cache-path

Before 12.0, --cache-s3-cache-path
$CACHE_PATH

Before 12.0, $S3_CACHE_PATH
Shared [runners.cache] -> Shared --cache-shared

Before 12.0, --cache-cache-shared
$CACHE_SHARED
S3.ServerAddress [runners.cache.s3] -> ServerAddress

Before 12.0, [runners.cache] -> ServerAddress
--cache-s3-server-address $CACHE_S3_SERVER_ADDRESS

Before 12.0, $S3_SERVER_ADDRESS
S3.AccessKey [runners.cache.s3] -> AccessKey

Before 12.0, [runners.cache] -> AccessKey
--cache-s3-access-key $CACHE_S3_ACCESS_KEY

Before 12.0, $S3_ACCESS_KEY
S3.SecretKey [runners.cache.s3] -> SecretKey

Before 12.0, [runners.cache] -> SecretKey
--cache-s3-secret-key $CACHE_S3_SECRET_KEY

Before 12.0, $S3_SECRET_KEY
S3.SessionToken [runners.cache.s3] -> SessionToken --cache-s3-session-token $CACHE_S3_SESSION_TOKEN
S3.BucketName [runners.cache.s3] -> BucketName

Before 12.0, [runners.cache] -> BucketName
--cache-s3-bucket-name $CACHE_S3_BUCKET_NAME

Before 12.0, $S3_BUCKET_NAME
S3.BucketLocation [runners.cache.s3] -> BucketLocation

Before 12.0, [runners.cache] -> BucketLocation
--cache-s3-bucket-location $CACHE_S3_BUCKET_LOCATION

Before 12.0, $S3_BUCKET_LOCATION
S3.Insecure [runners.cache.s3] -> Insecure

Before 12.0, [runners.cache] -> Insecure
--cache-s3-insecure $CACHE_S3_INSECURE

Before 12.0, $S3_INSECURE
S3.AuthenticationType [runners.cache.s3] -> AuthenticationType --cache-s3-authentication_type $CACHE_S3_AUTHENTICATION_TYPE
S3.ServerSideEncryption [runners.cache.s3] -> ServerSideEncryption --cache-s3-server-side-encryption $CACHE_S3_SERVER_SIDE_ENCRYPTION
S3.ServerSideEncryptionKeyID [runners.cache.s3] -> ServerSideEncryptionKeyID --cache-s3-server-side-encryption-key-id $CACHE_S3_SERVER_SIDE_ENCRYPTION_KEY_ID
GCS.AccessID [runners.cache.gcs] -> AccessID --cache-gcs-access-id $CACHE_GCS_ACCESS_ID
GCS.PrivateKey [runners.cache.gcs] -> PrivateKey --cache-gcs-private-key $CACHE_GCS_PRIVATE_KEY
GCS.CredentialsFile [runners.cache.gcs] -> CredentialsFile --cache-gcs-credentials-file $GOOGLE_APPLICATION_CREDENTIALS
GCS.BucketName [runners.cache.gcs] -> BucketName --cache-gcs-bucket-name $CACHE_GCS_BUCKET_NAME
Azure.AccountName [runners.cache.azure] -> AccountName --cache-azure-account-name $CACHE_AZURE_ACCOUNT_NAME
Azure.AccountKey [runners.cache.azure] -> AccountKey --cache-azure-account-key $CACHE_AZURE_ACCOUNT_KEY
Azure.ContainerName [runners.cache.azure] -> ContainerName --cache-azure-container-name $CACHE_AZURE_CONTAINER_NAME
Azure.StorageDomain [runners.cache.azure] -> StorageDomain --cache-azure-storage-domain $CACHE_AZURE_STORAGE_DOMAIN

The [runners.cache.s3] section

The following parameters define S3 storage for cache.

Parameter Type Description
ServerAddress string A host:port for the S3-compatible server. If you are using a server other than AWS, consult the storage product documentation to determine the correct address. For DigitalOcean, the address must be in the format spacename.region.digitaloceanspaces.com.
AccessKey string The access key specified for your S3 instance.
SecretKey string The secret key specified for your S3 instance.
SessionToken string The session token specified for your S3 instance when temporary credentials are used.
BucketName string Name of the storage bucket where cache is stored.
BucketLocation string Name of S3 region.
Insecure boolean Set to true if the S3 service is available by HTTP. Default is false.
AuthenticationType string Set to iam or access-key. Default is access-key if ServerAddress, AccessKey, and SecretKey are all provided. Defaults to iam if ServerAddress, AccessKey, or SecretKey are missing.
ServerSideEncryption string In GitLab 15.3 and later, server side encryption type used with S3 available types are S3, or KMS.
ServerSideEncryptionKeyID string In GitLab 15.3 and later, the alias or ID of a KMS key used for encryption if using KMS.

Example:

[runners.cache]
  Type = "s3"
  Path = "path/to/prefix"
  Shared = false
  [runners.cache.s3]
    ServerAddress = "s3.amazonaws.com"
    AccessKey = "AWS_S3_ACCESS_KEY"
    SecretKey = "AWS_S3_SECRET_KEY"
    BucketName = "runners-cache"
    BucketLocation = "eu-west-1"
    Insecure = false
    ServerSideEncryption = "KMS"
    ServerSideEncryptionKeyID = "alias/my-key"

If any of ServerAddress, AccessKey or SecretKey aren’t specified and AuthenticationType is not provided, the S3 client uses the IAM instance profile available to the gitlab-runner instance. In an autoscale configuration, this is not the on-demand machine that jobs are executed on. If ServerAddress, AccessKey and SecretKey are all specified but AuthenticationType is not provided, access-key will be used as the authentication type.

When you use Helm charts to install GitLab Runner, and rbac.create is set to true in the values.yaml file, a ServiceAccount is created. This ServiceAccount’s annotations are retrieved from the rbac.serviceAccountAnnotations section.

For runners on Amazon EKS, you can specify an IAM role to assign to the service account. The specific annotation needed is: eks.amazonaws.com/role-arn: arn:aws:iam::<ACCOUNT_ID>:role/<IAM_ROLE_NAME>.

The IAM policy for this role must have permissions to do the following actions for the specified bucket:

  • s3:PutObject
  • s3:GetObjectVersion
  • s3:GetObject
  • s3:DeleteObject

If you use ServerSideEncryption of type KMS, this role must also have permission to do the following actions for the specified AWS KMS Key:

  • kms:Encrypt
  • kms:Decrypt
  • kms:ReEncrypt*
  • kms:GenerateDataKey*
  • kms:DescribeKey

ServerSideEncryption of type SSE-C is not supported. SSE-C requires that the headers, which contain the user-supplied key, are provided for the download request, in addition to the presigned URL. This would mean passing the key material to the job, where the key can’t be kept safe. This does have the potential to leak the decryption key. A discussion about this issue is in this merge request.

note
The maximum size of a single file that can be uploaded to AWS S3 cache is 5 GB. A discussion about potential workarounds for this behavior is in this issue.

Use KMS key encryption in S3 bucket for runner cache

The GenerateDataKey API uses the KMS symmetric key to create a data key for client-side encryption (https://docs.aws.amazon.com/kms/latest/APIReference/API_GenerateDataKey.html). KMS key configuration must be as follows:

Attribute Description
Key Type Symmetric
Origin AWS_KMS
Key Spec SYMMETRIC_DEFAULT
Key Usage Encrypt and decrypt

The IAM policy for the role assigned to the ServiceAccount defined in rbac.serviceAccountName must have permissions to do the following actions for the KMS Key:

  • kms:GetPublicKey
  • kms:Decrypt
  • kms:Encrypt
  • kms:DescribeKey
  • kms:GenerateDataKey

Enable IAM roles for Kubernetes ServiceAccount resources

To use IAM roles for service accounts, an IAM OIDC provider must exist for your cluster. After an IAM OIDC provider is associated with your cluster, you can create an IAM role to associate to the service account of the runner.

  1. On the Create Role window, under Select type of trusted entity, select Web Identity.
  2. On the Trusted Relationships tab of the role:

    • The Trusted entities section must have the format: arn:aws:iam::<ACCOUNT_ID>:oidc-provider/oidc.eks.<AWS_REGION>.amazonaws.com/id/<OIDC_ID>. The OIDC ID can be found on EKS cluster’s Configuration tab.

    • The Condition section must have the GitLab Runner service account defined in rbac.serviceAccountName or the default service account created if rbac.create is set to true:

      Condition Key Value
      StringEquals oidc.eks.<AWS_REGION>.amazonaws.com/id/<OIDC_ID>:sub system:serviceaccount:<GITLAB_RUNNER_NAMESPACE>:<GITLAB_RUNNER_SERVICE_ACCOUNT>

The [runners.cache.gcs] section

The following parameters define native support for Google Cloud Storage. For more information about these values, see the Google Cloud Storage (GCS) authentication documentation.

Parameter Type Description
CredentialsFile string Path to the Google JSON key file. Only the service_account type is supported. If configured, this value takes precedence over the AccessID and PrivateKey configured directly in config.toml.
AccessID string ID of GCP Service Account used to access the storage.
PrivateKey string Private key used to sign GCS requests.
BucketName string Name of the storage bucket where cache is stored.

Examples:

Credentials configured directly in config.toml file:

[runners.cache]
  Type = "gcs"
  Path = "path/to/prefix"
  Shared = false
  [runners.cache.gcs]
    AccessID = "cache-access-account@test-project-123456.iam.gserviceaccount.com"
    PrivateKey = "-----BEGIN PRIVATE KEY-----\nXXXXXX\n-----END PRIVATE KEY-----\n"
    BucketName = "runners-cache"

Credentials in JSON file downloaded from GCP:

[runners.cache]
  Type = "gcs"
  Path = "path/to/prefix"
  Shared = false
  [runners.cache.gcs]
    CredentialsFile = "/etc/gitlab-runner/service-account.json"
    BucketName = "runners-cache"

Application Default Credentials (ADC) from the metadata server in GCP:

When you use GitLab Runner with Google Cloud ADC, you typically use the default service account. Then you don’t need to supply credentials for the instance:

[runners.cache]
  Type = "gcs"
  Path = "path/to/prefix"
  Shared = false
  [runners.cache.gcs]
    BucketName = "runners-cache"

If you use ADC, be sure that the service account that you use has the iam.serviceAccounts.signBlob permission. Typically this is done by granting the Service Account Token Creator role to the service account.

The [runners.cache.azure] section

History
  • Introduced in GitLab Runner 13.4.0.

The following parameters define native support for Azure Blob Storage. To learn more, view the Azure Blob Storage documentation. While S3 and GCS use the word bucket for a collection of objects, Azure uses the word container to denote a collection of blobs.

Parameter Type Description
AccountName string Name of the Azure Blob Storage account used to access the storage.
AccountKey string Storage account access key used to access the container.
ContainerName string Name of the storage container to save cache data in.
StorageDomain string Domain name used to service Azure storage endpoints (optional). Default is blob.core.windows.net.

Example:

[runners.cache]
  Type = "azure"
  Path = "path/to/prefix"
  Shared = false
  [runners.cache.azure]
    AccountName = "<AZURE STORAGE ACCOUNT NAME>"
    AccountKey = "<AZURE STORAGE ACCOUNT KEY>"
    ContainerName = "runners-cache"
    StorageDomain = "blob.core.windows.net"

The [runners.kubernetes] section

History
  • Introduced in GitLab Runner v1.6.0.

The following parameters define Kubernetes behavior. For more parameters, see the documentation for the Kubernetes executor.

Parameter Type Description
host string Optional. Kubernetes host URL. If not specified, the runner attempts to auto-discovery it.
cert_file string Optional. Kubernetes auth certificate.
key_file string Optional. Kubernetes auth private key.
ca_file string Optional. Kubernetes auth ca certificate.
image string Default Docker image to use for jobs when none is specified.
allowed_images array Wildcard list of images that are allowed in .gitlab-ci.yml. If not present all images are allowed (equivalent to ["*/*:*"]). Use with the Docker or Kubernetes executors.
allowed_services array Wildcard list of services that are allowed in .gitlab-ci.yml. If not present all images are allowed (equivalent to ["*/*:*"]). Use with the Docker or Kubernetes executors.
namespace string Namespace to run Kubernetes jobs in.
privileged boolean Run all containers with the privileged flag enabled.
allow_privilege_escalation boolean Optional. Runs all containers with the allowPrivilegeEscalation flag enabled.
node_selector table A table of key=value pairs of string=string. Limits the creation of pods to Kubernetes nodes that match all the key=value pairs.
image_pull_secrets array An array of items containing the Kubernetes docker-registry secret names used to authenticate Docker image pulling from private registries.

Example:

[runners.kubernetes]
  host = "https://45.67.34.123:4892"
  cert_file = "/etc/ssl/kubernetes/api.crt"
  key_file = "/etc/ssl/kubernetes/api.key"
  ca_file = "/etc/ssl/kubernetes/ca.crt"
  image = "golang:1.8"
  privileged = true
  allow_privilege_escalation = true
  image_pull_secrets = ["docker-registry-credentials", "optional-additional-credentials"]
  allowed_images = ["ruby:*", "python:*", "php:*"]
  allowed_services = ["postgres:9.4", "postgres:latest"]
  [runners.kubernetes.node_selector]
    gitlab = "true"

Helper image

When you use docker, docker+machine, or kubernetes executors, GitLab Runner uses a specific container to handle Git, artifacts, and cache operations. This container is created from an image named helper image.

The helper image is available for amd64, arm, arm64, s390x, and ppc64le architectures. It contains a gitlab-runner-helper binary, which is a special compilation of GitLab Runner binary. It contains only a subset of available commands, as well as Git, Git LFS and SSL certificates store.

The helper image has a few flavors: alpine, alpine3.16, alpine3.17, alpine3.18, alpine3.19, alpine-latest, ubi-fips and ubuntu. The alpine image is currently the default due to its small footprint but can have DNS issues in some environments. Using helper_image_flavor = "ubuntu" will select the ubuntu flavor of the helper image.

In GitLab Runner 16.1 and later the alpine flavor is an alias for alpine3.18.

The alpine-latest flavor uses alpine:latest as its base image, which could potentially mean it will be more unstable.

When GitLab Runner is installed from the DEB/RPM packages, images for the supported architectures are installed on the host. When the runner prepares to execute the job, if the image in the specified version (based on the runner’s Git revision) is not found on Docker Engine, it is automatically loaded. Both the docker and docker+machine executors work this way.

For the alpine flavors, only the default alpine flavor image is included in the package. All other flavors will be downloaded from the registry.

The kubernetes executor and manual installations of GitLab Runner work differently.

  • For manual installations, the gitlab-runner-helper binary is not included.
  • For the kubernetes executor, the Kubernetes API doesn’t allow the gitlab-runner-helper image to be loaded from a local archive.

In both cases, GitLab Runner downloads the helper image. The GitLab Runner revision and architecture define which tag to download.

Helper image configuration for Kubernetes on Arm

To use the arm64 helper image on arm64 Kubernetes clusters, set the following values in your configuration file.

[runners.kubernetes]
        helper_image = "gitlab/gitlab-runner-helper:arm64-latest"

Runner images that use an old version of Alpine Linux

History

Images are built with multiple versions of Alpine Linux, so you can use a newer version of Alpine, but at the same time use older versions as well.

For the helper image, change the helper_image_flavor or read the Helper image section.

For the GitLab Runner image, follow the same logic, where alpine, alpine3.16, alpine3.17, alpine3.18, alpine3.19 or alpine-latest is used as a prefix in the image, before the version:

docker pull gitlab/gitlab-runner:alpine3.18-v16.1.0

Alpine pwsh images

As of GitLab Runner 16.1 and later all alpine helper images have a pwsh variant. The only exception being alpine-latest as the pwsh Docker images which the GitLab Runner helper images are based on do not support alpine:latest.

Example:

docker pull gitlab/gitlab-runner-helper:alpine3.18-x86_64-v16.1.0-pwsh

Helper image registry

In GitLab 15.0 and later, the helper image is pulled from the GitLab Container Registry.

In GitLab 15.0 and earlier, you configure helper images to use images from Docker Hub. To retrieve the base gitlab-runner-helper image from the GitLab registry, use a helper-image value: registry.gitlab.com/gitlab-org/gitlab-runner/gitlab-runner-helper:x86_64-v${CI_RUNNER_VERSION}.

Self-managed instances also pull the helper image from the GitLab Container Registry on GitLab.com. To check the status of the GitLab Container Registry, see the GitLab System Status.

Override the helper image

In some cases, you may need to override the helper image. There are many reasons for doing this:

  1. To speed up jobs execution: In environments with slower internet connection, downloading the same image multiple times can increase the time it takes to execute a job. Downloading the helper image from a local registry, where the exact copy of gitlab/gitlab-runner-helper:XYZ is stored, can speed things up.

  2. Security concerns: You may not want to download external dependencies that were not checked before. There might be a business rule to use only dependencies that were reviewed and stored in local repositories.

  3. Build environments without internet access: In some cases, jobs are executed in an environment that has a dedicated, closed network. This doesn’t apply to the kubernetes executor, where the image still needs to be downloaded from an external registry that is available to the Kubernetes cluster.

  4. Additional software: You may want to install some additional software to the helper image, like openssh to support submodules accessible with git+ssh instead of git+http.

In these cases, you can configure a custom image by using the helper_image configuration field, which is available for the docker, docker+machine, and kubernetes executors:

[[runners]]
  (...)
  executor = "docker"
  [runners.docker]
    (...)
    helper_image = "my.registry.local/gitlab/gitlab-runner-helper:tag"

The version of the helper image should be considered to be strictly coupled with the version of GitLab Runner. One of the main reasons for providing these images is that GitLab Runner is using the gitlab-runner-helper binary. This binary is compiled from part of the GitLab Runner source. This binary uses an internal API that is expected to be the same in both binaries.

By default, GitLab Runner references a gitlab/gitlab-runner-helper:XYZ image, where XYZ is based on the GitLab Runner architecture and Git revision. In GitLab Runner 11.3 and later, you can define the image version by using one of the version variables:

[[runners]]
  (...)
  executor = "docker"
  [runners.docker]
    (...)
    helper_image = "my.registry.local/gitlab/gitlab-runner-helper:x86_64-v${CI_RUNNER_VERSION}"

With this configuration, GitLab Runner instructs the executor to use the image in version x86_64-v${CI_RUNNER_VERSION}, which is based on its compilation data. After updating GitLab Runner to a new version, GitLab Runner tries to download the proper image. The image should be uploaded to the registry before upgrading GitLab Runner, otherwise the jobs start failing with a “No such image” error.

In GitLab Runner 13.2 and later, the helper image is tagged by $CI_RUNNER_VERSION in addition to $CI_RUNNER_REVISION. Both tags are valid and point to the same image.

[[runners]]
  (...)
  executor = "docker"
  [runners.docker]
    (...)
    helper_image = "my.registry.local/gitlab/gitlab-runner-helper:x86_64-v${CI_RUNNER_VERSION}"

When using PowerShell Core

An additional version of the helper image for Linux, which contains PowerShell Core, is published with the gitlab/gitlab-runner-helper:XYZ-pwsh tag.

The [runners.custom_build_dir] section

History

This section defines custom build directories parameters.

This feature, if not configured explicitly, is enabled by default for kubernetes, docker and docker+machine executors. For all other executors, it is disabled by default.

This feature requires that GIT_CLONE_PATH is in a path defined in runners.builds_dir. To use the builds_dir, use the $CI_BUILDS_DIR variable.

By default, this feature is enabled only for docker and kubernetes executors, because they provide a good way to separate resources. This feature can be explicitly enabled for any executor, but use caution when you use it with executors that share builds_dir and have concurrent > 1.

Parameter Type Description
enabled boolean Allow user to define a custom build directory for a job.

Example:

[runners.custom_build_dir]
  enabled = true

Default Build Directory

GitLab Runner clones the repository to a path that exists under a base path better known as the Builds Directory. The default location of this base directory depends on the executor. For:

  • Kubernetes, Docker and Docker Machine executors, it is /builds inside of the container.
  • Shell executor, it is $PWD/builds.
  • SSH, VirtualBox and Parallels executors, it is ~/builds in the home directory of the user configured to handle the SSH connection to the target machine.
  • Custom executors, no default is provided and it must be explicitly configured, otherwise, the job fails.

The used Builds Directory may be defined explicitly by the user with the builds_dir setting.

note
You can also specify GIT_CLONE_PATH if you want to clone to a custom directory, and the guideline below doesn’t apply.

GitLab Runner uses the Builds Directory for all the jobs that it runs, but nests them using a specific pattern {builds_dir}/$RUNNER_TOKEN_KEY/$CONCURRENT_ID/$NAMESPACE/$PROJECT_NAME. For example: /builds/2mn-ncv-/0/user/playground.

GitLab Runner does not stop you from storing things inside of the Builds Directory. For example, you can store tools inside of /builds/tools that can be used during CI execution. We HIGHLY discourage this, you should never store anything inside of the Builds Directory. GitLab Runner should have total control over it and does not provide stability in such cases. If you have dependencies that are required for your CI, we recommend installing them in some other place.

The [runners.referees] section

Use GitLab Runner referees to pass extra job monitoring data to GitLab. Referees are workers in the runner manager that query and collect additional data related to a job. The results are uploaded to GitLab as job artifacts.

Use the Metrics Runner referee

If the machine or container running the job exposes Prometheus metrics, GitLab Runner can query the Prometheus server for the entirety of the job duration. After the metrics are received, they are uploaded as a job artifact that can be used for analysis later.

Only the docker-machine executor supports the referee.

Configure the Metrics Runner Referee for GitLab Runner

Define [runner.referees] and [runner.referees.metrics] in your config.toml file within a [[runner]] section and add the following fields:

Setting Description
prometheus_address The server that collects metrics from GitLab Runner instances. It must be accessible by the runner manager when the job finishes.
query_interval The frequency the Prometheus instance associated with a job is queried for time series data, defined as an interval (in seconds).
queries An array of PromQL queries that are executed for each interval.

Here is a complete configuration example for node_exporter metrics:

[[runners]]
  [runners.referees]
    [runners.referees.metrics]
      prometheus_address = "http://localhost:9090"
      query_interval = 10
      metric_queries = [
        "arp_entries:rate(node_arp_entries{{selector}}[{interval}])",
        "context_switches:rate(node_context_switches_total{{selector}}[{interval}])",
        "cpu_seconds:rate(node_cpu_seconds_total{{selector}}[{interval}])",
        "disk_read_bytes:rate(node_disk_read_bytes_total{{selector}}[{interval}])",
        "disk_written_bytes:rate(node_disk_written_bytes_total{{selector}}[{interval}])",
        "memory_bytes:rate(node_memory_MemTotal_bytes{{selector}}[{interval}])",
        "memory_swap_bytes:rate(node_memory_SwapTotal_bytes{{selector}}[{interval}])",
        "network_tcp_active_opens:rate(node_netstat_Tcp_ActiveOpens{{selector}}[{interval}])",
        "network_tcp_passive_opens:rate(node_netstat_Tcp_PassiveOpens{{selector}}[{interval}])",
        "network_receive_bytes:rate(node_network_receive_bytes_total{{selector}}[{interval}])",
        "network_receive_drops:rate(node_network_receive_drop_total{{selector}}[{interval}])",
        "network_receive_errors:rate(node_network_receive_errs_total{{selector}}[{interval}])",
        "network_receive_packets:rate(node_network_receive_packets_total{{selector}}[{interval}])",
        "network_transmit_bytes:rate(node_network_transmit_bytes_total{{selector}}[{interval}])",
        "network_transmit_drops:rate(node_network_transmit_drop_total{{selector}}[{interval}])",
        "network_transmit_errors:rate(node_network_transmit_errs_total{{selector}}[{interval}])",
        "network_transmit_packets:rate(node_network_transmit_packets_total{{selector}}[{interval}])"
      ]

Metrics queries are in canonical_name:query_string format. The query string supports two variables that are replaced during execution:

Setting Description
{selector} Replaced with a label_name=label_value pair that selects metrics generated in Prometheus by a specific GitLab Runner instance.
{interval} Replaced with the query_interval parameter from the [runners.referees.metrics] configuration for this referee.

For example, a shared GitLab Runner environment that uses the docker-machine executor would have a {selector} similar to node=shared-runner-123.