Using the GitLab-Gitaly chart

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The gitaly sub-chart provides a configurable deployment of Gitaly Servers.

Requirements

This chart depends on access to the Workhorse service, either as part of the complete GitLab chart or provided as an external service reachable from the Kubernetes cluster this chart is deployed onto.

Design Choices

The Gitaly container used in this chart also contains the GitLab Shell codebase in order to perform the actions on the Git repositories that have not yet been ported into Gitaly. The Gitaly container includes a copy of the GitLab Shell container within it, and as a result we also need to configure GitLab Shell within this chart.

Configuration

The gitaly chart is configured in two parts: external services, and chart settings.

Gitaly is by default deployed as a component when deploying the GitLab chart. If deploying Gitaly separately, global.gitaly.enabled needs to be set to false and additional configuration will need to be performed as described in the external Gitaly documentation.

Installation command line options

The table below contains all the possible charts configurations that can be supplied to the helm install command using the --set flags.

Parameter Default Description
annotations   Pod annotations
backup.goCloudUrl   Object storage URL for server side Gitaly backups.
common.labels {} Supplemental labels that are applied to all objects created by this chart.
podLabels   Supplemental Pod labels. Will not be used for selectors.
external[].hostname - "" hostname of external node
external[].name - "" name of external node storage
external[].port - "" port of external node
extraContainers   List of extra containers to include
extraInitContainers   List of extra init containers to include
extraVolumeMounts   List of extra volumes mounts to do
extraVolumes   List of extra volumes to create
extraEnv   List of extra environment variables to expose
extraEnvFrom   List of extra environment variables from other data sources to expose
gitaly.serviceName   The name of the generated Gitaly service. Overrides global.gitaly.serviceName, and defaults to <RELEASE-NAME>-gitaly
gpgSigning.enabled false If Gitaly GPG signing should be used.
gpgSigning.secret   The name of the secret used for Gitaly GPG signing.
gpgSigning.key   The key in the GPG secret containing Gitaly’s GPG signing key.
image.pullPolicy Always Gitaly image pull policy
image.pullSecrets   Secrets for the image repository
image.repository registry.gitlab.com/gitlab-org/build/cng/gitaly Gitaly image repository
image.tag master Gitaly image tag
init.image.repository   initContainer image
init.image.tag   initContainer image tag
init.containerSecurityContext   initContainer container specific securityContext
internal.names[] - default Ordered names of StatefulSet storages
serviceLabels {} Supplemental service labels
service.externalPort 8075 Gitaly service exposed port
service.internalPort 8075 Gitaly internal port
service.name gitaly The name of the Service port that Gitaly is behind in the Service object.
service.type ClusterIP Gitaly service type
securityContext.fsGroup 1000 Group ID under which the pod should be started
securityContext.fsGroupChangePolicy   Policy for changing ownership and permission of the volume (requires Kubernetes 1.23)
securityContext.runAsUser 1000 User ID under which the pod should be started
containerSecurityContext   Override container securityContext under which the Gitaly container is started
containerSecurityContext.runAsUser 1000 Allow to overwrite the specific security context under which the Gitaly container is started
tolerations [] Toleration labels for pod assignment
affinity {} Affinity rules for pod assignment
persistence.accessMode ReadWriteOnce Gitaly persistence access mode
persistence.annotations   Gitaly persistence annotations
persistence.enabled true Gitaly enable persistence flag
persistance.labels   Gitaly persistence labels
persistence.matchExpressions   Label-expression matches to bind
persistence.matchLabels   Label-value matches to bind
persistence.size 50Gi Gitaly persistence volume size
persistence.storageClass   storageClassName for provisioning
persistence.subPath   Gitaly persistence volume mount path
priorityClassName   Gitaly StatefulSet priorityClassName
logging.level   Log level
logging.format json Log format
logging.sentryDsn   Sentry DSN URL - Exceptions from Go server
logging.sentryEnvironment   Sentry environment to be used for logging
shell.concurrency[]   Concurrency of each RPC endpoint Specified using keys rpc and maxPerRepo
packObjectsCache.enabled false Enable the Gitaly pack-objects cache
packObjectsCache.dir /home/git/repositories/+gitaly/PackObjectsCache Directory where cache files get stored
packObjectsCache.max_age 5m Cache entries lifespan
packObjectsCache.min_occurrences 1 Key must hit a minimum count to create a cache entry
git.catFileCacheSize   Cache size used by Git cat-file process
git.config[] [] Git configuration that Gitaly should set when spawning Git commands
prometheus.grpcLatencyBuckets   Buckets corresponding to histogram latencies on GRPC method calls to be recorded by Gitaly. A string form of the array (for example, "[1.0, 1.5, 2.0]") is required as input
statefulset.strategy {} Allows one to configure the update strategy utilized by the StatefulSet
statefulset.livenessProbe.initialDelaySeconds 30 Delay before liveness probe is initiated. If startupProbe is enabled, this will be set to 0.
statefulset.livenessProbe.periodSeconds 10 How often to perform the liveness probe
statefulset.livenessProbe.timeoutSeconds 3 When the liveness probe times out
statefulset.livenessProbe.successThreshold 1 Minimum consecutive successes for the liveness probe to be considered successful after having failed
statefulset.livenessProbe.failureThreshold 3 Minimum consecutive failures for the liveness probe to be considered failed after having succeeded
statefulset.readinessProbe.initialDelaySeconds 10 Delay before readiness probe is initiated. If startupProbe is enabled, this will be set to 0.
statefulset.readinessProbe.periodSeconds 10 How often to perform the readiness probe
statefulset.readinessProbe.timeoutSeconds 3 When the readiness probe times out
statefulset.readinessProbe.successThreshold 1 Minimum consecutive successes for the readiness probe to be considered successful after having failed
statefulset.readinessProbe.failureThreshold 3 Minimum consecutive failures for the readiness probe to be considered failed after having succeeded
statefulset.startupProbe.enabled false Whether a startup probe is enabled.
statefulset.startupProbe.initialDelaySeconds 1 Delay before startup probe is initiated
statefulset.startupProbe.periodSeconds 2 How often to perform the startup probe
statefulset.startupProbe.timeoutSeconds 1 When the startup probe times out
statefulset.startupProbe.successThreshold 1 Minimum consecutive successes for the startup probe to be considered successful after having failed
statefulset.startupProbe.failureThreshold 30 Minimum consecutive failures for the startup probe to be considered failed after having succeeded
metrics.enabled false If a metrics endpoint should be made available for scraping
metrics.port 9236 Metrics endpoint port
metrics.path /metrics Metrics endpoint path
metrics.serviceMonitor.enabled false If a ServiceMonitor should be created to enable Prometheus Operator to manage the metrics scraping, note that enabling this removes the prometheus.io scrape annotations
metrics.serviceMonitor.additionalLabels {} Additional labels to add to the ServiceMonitor
metrics.serviceMonitor.endpointConfig {} Additional endpoint configuration for the ServiceMonitor
metrics.metricsPort   DEPRECATED Use metrics.port
gomemlimit.enabled true This will automatically set the GOMEMLIMIT environment variable for the Gitaly container to resources.limits.memory, if that limit is also set. Users can override this value by setting this value false and setting GOMEMLIMIT in extraEnv. This must meet documented format criteria.
cgroups.enabled false Gitaly has built-in cgroups control. When configured, Gitaly assigns Git processes to a cgroup based on the repository the Git command is operating in. This parameter will enable repository cgroups. Note only cgroups v2 will be supported if enabled.
cgroups.initContainer.image.repository registry.com/gitlab-org/build/cng/gitaly-init-cgroups Gitaly image repository
cgroups.initContainer.image.tag master Gitaly image tag
cgroups.initContainer.image.pullPolicy IfNotPresent Gitaly image pull policy
cgroups.mountpoint /etc/gitlab-secrets/gitaly-pod-cgroup Where the parent cgroup directory is mounted.
cgroups.hierarchyRoot gitaly Parent cgroup under which Gitaly creates groups, and is expected to be owned by the user and group Gitaly runs as.
cgroups.memoryBytes   The total memory limit that is imposed collectively on all Git processes that Gitaly spawns. 0 implies no limit.
cgroups.cpuShares   The CPU limit that is imposed collectively on all Git processes that Gitaly spawns. 0 implies no limit. The maximum is 1024 shares, which represents 100% of CPU.
cgroups.cpuQuotaUs   Used to throttle the cgroups’ processes if they exceed this quota value. We set cpuQuotaUs to 100ms so 1 core is 100000. 0 implies no limit.
cgroups.repositories.count   The number of cgroups in the cgroups pool. Each time a new Git command is spawned, Gitaly assigns it to one of these cgroups based on the repository the command is for. A circular hashing algorithm assigns Git commands to these cgroups, so a Git command for a repository is always assigned to the same cgroup.
cgroups.repositories.memoryBytes   The total memory limit imposed on all Git processes contained in a repository cgroup. 0 implies no limit. This value cannot exceed that of the top level memoryBytes.
cgroups.repositories.cpuShares   The CPU limit that is imposed on all Git processes contained in a repository cgroup. 0 implies no limit. The maximum is 1024 shares, which represents 100% of CPU. This value cannot exceed that of the top level cpuShares.
cgroups.repositories.cpuQuotaUs   The cpuQuotaUs that is imposed on all Git processes contained in a repository cgroup. A Git process can’t use more then the given quota. We set cpuQuotaUs to 100ms so 1 core is 100000. 0 implies no limit.
gracefulRestartTimeout 25 Gitaly shutdown grace period, how long to wait for in-flight requests to complete (seconds). Pod terminationGracePeriodSeconds is set to this value + 5 seconds.

Chart configuration examples

extraEnv

extraEnv allows you to expose additional environment variables in all containers in the pods.

Below is an example use of extraEnv:

extraEnv:
  SOME_KEY: some_value
  SOME_OTHER_KEY: some_other_value

When the container is started, you can confirm that the environment variables are exposed:

env | grep SOME
SOME_KEY=some_value
SOME_OTHER_KEY=some_other_value

extraEnvFrom

extraEnvFrom allows you to expose additional environment variables from other data sources in all containers in the pods.

Below is an example use of extraEnvFrom:

extraEnvFrom:
  MY_NODE_NAME:
    fieldRef:
      fieldPath: spec.nodeName
  MY_CPU_REQUEST:
    resourceFieldRef:
      containerName: test-container
      resource: requests.cpu
  SECRET_THING:
    secretKeyRef:
      name: special-secret
      key: special_token
      # optional: boolean
  CONFIG_STRING:
    configMapKeyRef:
      name: useful-config
      key: some-string
      # optional: boolean

image.pullSecrets

pullSecrets allows you to authenticate to a private registry to pull images for a pod.

Additional details about private registries and their authentication methods can be found in the Kubernetes documentation.

Below is an example use of pullSecrets

image:
  repository: my.gitaly.repository
  tag: latest
  pullPolicy: Always
  pullSecrets:
  - name: my-secret-name
  - name: my-secondary-secret-name

tolerations

tolerations allow you schedule pods on tainted worker nodes

Below is an example use of tolerations:

tolerations:
- key: "node_label"
  operator: "Equal"
  value: "true"
  effect: "NoSchedule"
- key: "node_label"
  operator: "Equal"
  value: "true"
  effect: "NoExecute"

affinity

For more information, see affinity.

annotations

annotations allows you to add annotations to the Gitaly pods.

Below is an example use of annotations:

annotations:
  kubernetes.io/example-annotation: annotation-value

priorityClassName

priorityClassName allows you to assign a PriorityClass to the Gitaly pods.

Below is an example use of priorityClassName:

priorityClassName: persistence-enabled

git.config

git.config allows you to add configuration to all Git commands spawned by Gitaly. Accepts configuration as documented in git-config(1) in key / value pairs, as shown below.

git:
  config:
    - key: "pack.threads"
      value: 4
    - key: "fsck.missingSpaceBeforeDate"
      value: ignore

cgroups

To prevent exhaustion, Gitaly uses cgroups to assign Git processes to a cgroup based on the repository being operated on. Each cgroup has memory and CPU limits, ensuring system stability and preventing resource saturation.

Please note that the initContainer that runs before Gitaly starts requires to be executed as root. This container will configure the permissions so that Gitaly can manage cgroups. Hence, it will mount a volume on the filesystem to have write access to /sys/fs/cgroup.

Example of Oversubscription

cgroups:
  enabled: true
  # Total limit across all repository cgroups
  memoryBytes: 64424509440 # 60GiB
  cpuShares: 1024
  cpuQuotaUs: 1200000 # 12 cores
  # Per repository limits, 1000 repository cgroups
  repositories:
    count: 1000
    memoryBytes: 32212254720 # 30GiB
    cpuShares: 512
    cpuQuotaUs: 400000 # 4 cores

External Services

This chart should be attached the Workhorse service.

Workhorse

workhorse:
  host: workhorse.example.com
  serviceName: webservice
  port: 8181
Name Type Default Description
host String   The hostname of the Workhorse server. This can be omitted in lieu of serviceName.
port Integer 8181 The port on which to connect to the Workhorse server.
serviceName String webservice The name of the service which is operating the Workhorse server. If this is present, and host is not, the chart will template the hostname of the service (and current .Release.Name) in place of the host value. This is convenient when using Workhorse as a part of the overall GitLab chart.

Chart settings

The following values are used to configure the Gitaly Pods.

note
Gitaly uses an Auth Token to authenticate with the Workhorse and Sidekiq services. The Auth Token secret and key are sourced from the global.gitaly.authToken value. Additionally, the Gitaly container has a copy of GitLab Shell, which has some configuration that can be set. The Shell authToken is sourced from the global.shell.authToken values.

Git Repository Persistence

This chart provisions a PersistentVolumeClaim and mounts a corresponding persistent volume for the Git repository data. You’ll need physical storage available in the Kubernetes cluster for this to work. If you’d rather use emptyDir, disable PersistentVolumeClaim with: persistence.enabled: false.

note
The persistence settings for Gitaly are used in a volumeClaimTemplate that should be valid for all your Gitaly pods. You should not include settings that are meant to reference a single specific volume (such as volumeName). If you want to reference a specific volume, you need to manually create the PersistentVolumeClaim.
note
You can’t change these through our settings once you’ve deployed. In StatefulSet the VolumeClaimTemplate is immutable.
persistence:
  enabled: true
  storageClass: standard
  accessMode: ReadWriteOnce
  size: 50Gi
  matchLabels: {}
  matchExpressions: []
  subPath: "data"
  annotations: {}
Name Type Default Description
accessMode String ReadWriteOnce Sets the accessMode requested in the PersistentVolumeClaim. See Kubernetes Access Modes Documentation for details.
enabled Boolean true Sets whether or not to use a PersistentVolumeClaims for the repository data. If false, an emptyDir volume is used.
matchExpressions Array   Accepts an array of label condition objects to match against when choosing a volume to bind. This is used in the PersistentVolumeClaim selector section. See the volumes documentation.
matchLabels Map   Accepts a Map of label names and label values to match against when choosing a volume to bind. This is used in the PersistentVolumeClaim selector section. See the volumes documentation.
size String 50Gi The minimum volume size to request for the data persistence.
storageClass String   Sets the storageClassName on the Volume Claim for dynamic provisioning. When unset or null, the default provisioner will be used. If set to a hyphen, dynamic provisioning is disabled.
subPath String   Sets the path within the volume to mount, rather than the volume root. The root is used if the subPath is empty.
annotations Map   Sets the annotations on the Volume Claim for dynamic provisioning. See Kubernetes Annotations Documentation for details.

Running Gitaly over TLS

note
This section refers to Gitaly being run inside the cluster using the Helm charts. If you are using an external Gitaly instance and want to use TLS for communicating with it, refer the external Gitaly documentation

Gitaly supports communicating with other components over TLS. This is controlled by the settings global.gitaly.tls.enabled and global.gitaly.tls.secretName. Follow the steps to run Gitaly over TLS:

  1. The Helm chart expects a certificate to be provided for communicating over TLS with Gitaly. This certificate should apply to all the Gitaly nodes that are present. Hence all hostnames of each of these Gitaly nodes should be added as a Subject Alternate Name (SAN) to the certificate.

    To know the hostnames to use, check the file /srv/gitlab/config/gitlab.yml file in the Toolbox pod and check the various gitaly_address fields specified under repositories.storages key within it.

    kubectl exec -it <Toolbox pod> -- grep gitaly_address /srv/gitlab/config/gitlab.yml
    
note
A basic script for generating custom signed certificates for internal Gitaly pods can be found in this repository. Users can use or refer that script to generate certificates with proper SAN attributes.
  1. Create a k8s TLS secret using the certificate created.

    kubectl create secret tls gitaly-server-tls --cert=gitaly.crt --key=gitaly.key
    
  2. Redeploy the Helm chart by passing --set global.gitaly.tls.enabled=true.

Global server hooks

The Gitaly StatefulSet has support for Global server hooks. The hook scripts run on the Gitaly pod, and are therefore limited to the tools available in the Gitaly container.

The hooks are populated using ConfigMaps, and can be used by setting the following values as appropriate:

  1. global.gitaly.hooks.preReceive.configmap
  2. global.gitaly.hooks.postReceive.configmap
  3. global.gitaly.hooks.update.configmap

To populate the ConfigMap, you can point kubectl to a directory of scripts:

kubectl create configmap MAP_NAME --from-file /PATH/TO/SCRIPT/DIR

GPG signing commits created by GitLab

Gitaly has the ability to GPG sign all commits created via the GitLab UI, e.g. the WebIDE, as well as commits created by GitLab, such as merge commits and squashes.

  1. Create a k8s secret using your GPG private key.

    kubectl create secret generic gitaly-gpg-signing-key --from-file=signing_key=/path/to/gpg_signing_key.gpg
    
  2. Enable GPG signing in your values.yaml.

    gitlab:
      gitaly:
        gpgSigning:
          enabled: true
          secret: gitaly-gpg-signing-key
          key: signing_key
    

Server-side backups

The chart supports Gitaly server-side backups. To use them:

  1. Create a bucket to store the backups.
  2. Configure the object store credentials and the storage URL.

    gitlab:
      gitaly:
        extraEnvFrom:
           # Mount the exisitign object store secret to the expected environment variables.
           AWS_ACCESS_KEY_ID:
             secretKeyRef:
               name: <Rails object store secret>
               key: aws_access_key_id
           AWS_SECRET_ACCESS_KEY:
             secretKeyRef:
               name: <Rails object store secret>
               key: aws_secret_access_key
        backup:
          # This is the connection string for Gitaly server side backups.
          goCloudUrl: <object store connection URL>
    

    For the expected environment variables and storage URL format for your object storage backend, see the Gitaly documentation.

  3. Enable server-side backups with backup-utility.