Using the GitLab kas chart

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The kas sub-chart provides a configurable deployment of the GitLab agent server (KAS). The agent server is a component you install together with GitLab. It is required to manage the GitLab agent for Kubernetes.

This chart depends on access to the GitLab API and the Gitaly Servers. When you enable this chart, an Ingress is deployed.

To consume minimal resources, the kas container uses a distroless image. The deployed services are exposed by an Ingress, which uses WebSocket proxying for communication. This proxy allows long-lived connections with the external component, agentk. agentk is the Kubernetes cluster-side agent counterpart.

The route to access the service depends on your Ingress configuration.

For more information, see the GitLab agent for Kubernetes architecture.

Disable the agent server

The GitLab agent server (kas) is enabled by default. To disable it on your GitLab instance, set the Helm property global.kas.enabled to false.

For example: 

helm upgrade --install kas --set global.kas.enabled=false

Specify an Ingress

When you use the chart’s Ingress with the default configuration, the service for the agent server is reachable on a subdomain. For example, for global.hosts.domain: example.com, the agent server is reachable at kas.example.com.

The KAS Ingress can use a different domain than the global.hosts.domain.

Set global.hosts.kas.name, for example: 

global.hosts.kas.name: kas.my-other-domain.com

This example uses kas.my-other-domain.com as the host for the KAS Ingress alone. The rest of the services (including GitLab, Registry, MinIO, etc.) use the domain specified in global.hosts.domain.

Installation command line options

You can pass these parameters to the helm install command by using the --set flags.

Parameter Default Description
affinity {} Affinity rules for pod assignment
annotations {} Pod annotations.
common.labels {} Supplemental labels that are applied to all objects created by this chart.
securityContext.runAsUser 65532 User ID under which the pod should be started
securityContext.runAsGroup 65534 Group ID under which the pod should be started
securityContext.fsGroup 65532 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.seccompProfile.type RuntimeDefault Seccomp profile to use
containerSecurityContext.runAsUser 65532 Override container securityContext user ID under which the container is started
containerSecurityContext.allowPrivilegeEscalation false Controls whether a process of the container can gain more privileges than its parent process
containerSecurityContext.runAsNonRoot true Controls whether the container runs with a non-root user
containerSecurityContext.capabilities.drop [ "ALL" ] Removes Linux capabilities for the Gitaly container
extraContainers   List of extra containers to include.
extraEnv   List of extra environment variables to expose
extraEnvFrom   List of extra environment variables from other data sources to expose
init.containerSecurityContext   init container securityContext overrides
init.containerSecurityContext.allowPrivilegeEscalation false initContainer specific: Controls whether a process can gain more privileges than its parent process
init.containerSecurityContext.runAsNonRoot true initContainer specific: Controls whether the container runs with a non-root user
init.containerSecurityContext.capabilities.drop [ "ALL" ] initContainer specific: Removes Linux capabilities for the container
image.repository registry.gitlab.com/gitlab-org/build/cng/gitlab-kas Image repository.
image.tag v13.7.0 Image tag.
hpa.behavior {scaleDown: {stabilizationWindowSeconds: 300 }} Behavior contains the specifications for up- and downscaling behavior (requires autoscaling/v2beta2 or higher).
hpa.customMetrics [] Custom metrics contains the specifications for which to use to calculate the desired replica count (overrides the default use of Average CPU Utilization configured in targetAverageUtilization).
hpa.cpu.targetType AverageValue Set the autoscaling CPU target type, must be either Utilization or AverageValue.
hpa.cpu.targetAverageValue 100m Set the autoscaling CPU target value.
hpa.cpu.targetAverageUtilization   Set the autoscaling CPU target utilization.
hpa.memory.targetType   Set the autoscaling memory target type, must be either Utilization or AverageValue.
hpa.memory.targetAverageValue   Set the autoscaling memory target value.
hpa.memory.targetAverageUtilization   Set the autoscaling memory target utilization.
hpa.targetAverageValue   DEPRECATED Set the autoscaling CPU target value
ingress.enabled true if global.kas.enabled=true You can use kas.ingress.enabled to explicitly turn it on or off. If not set, you can optionally use global.ingress.enabled for the same purpose.
ingress.apiVersion   Value to use in the apiVersion field.
ingress.annotations {} Ingress annotations.
ingress.tls {} Ingress TLS configuration.
ingress.agentPath / Ingress path for the agent API endpoint.
ingress.k8sApiPath /k8s-proxy Ingress path for Kubernetes API endpoint.
keda.enabled false Use KEDA ScaledObjects instead of HorizontalPodAutoscalers
keda.pollingInterval 30 The interval to check each trigger on
keda.cooldownPeriod 300 The period to wait after the last trigger reported active before scaling the resource back to 0
keda.minReplicaCount   Minimum number of replicas KEDA will scale the resource down to, defaults to minReplicas
keda.maxReplicaCount   Maximum number of replicas KEDA will scale the resource up to, defaults to maxReplicas
keda.fallback   KEDA fallback configuration, see the documentation
keda.hpaName   The name of the HPA resource KEDA will create, defaults to keda-hpa-{scaled-object-name}
keda.restoreToOriginalReplicaCount   Specifies whether the target resource should be scaled back to original replicas count after the ScaledObject is deleted
keda.behavior   The specifications for up- and downscaling behavior, defaults to hpa.behavior
keda.triggers   List of triggers to activate scaling of the target resource, defaults to triggers computed from hpa.cpu and hpa.memory
metrics.enabled true If a metrics endpoint should be made available for scraping.
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. Enabling removes the prometheus.io scrape annotations. It cannot be enabled together with metrics.podMonitor.enabled.
metrics.serviceMonitor.additionalLabels {} Additional labels to add to the ServiceMonitor.
metrics.serviceMonitor.endpointConfig {} Additional endpoint configuration for the ServiceMonitor.
metrics.podMonitor.enabled false If a PodMonitor should be created to enable Prometheus Operator to manage the metrics scraping. Enabling removes the prometheus.io scrape annotations. It cannot be enabled together with metrics.serviceMonitor.enabled.
metrics.podMonitor.additionalLabels {} Additional labels to add to the PodMonitor.
metrics.podMonitor.endpointConfig {} Additional endpoint configuration for the PodMonitor.
maxReplicas 10 HPA maxReplicas.
maxUnavailable 1 HPA maxUnavailable.
minReplicas 2 HPA maxReplicas.
nodeSelector   Define a nodeSelector for the Pods of this Deployment, if present.
observability.port 8151 Observability endpoint port. Used for metrics and probe endpoints.
observability.livenessProbe.path /liveness URI for the liveness probe endpoint. This value has to match the observability.liveness_probe.url_path value from the KAS service configuration.
observability.readinessProbe.path /readiness URI for the readiness probe endpoint. This value has to match the observability.readiness_probe.url_path value from the KAS service configuration.
serviceAccount.annotations {} Service account annotations.
podLabels {} Supplemental Pod labels. Not used for selectors.
serviceLabels {} Supplemental service labels.
common.labels   Supplemental labels that are applied to all objects created by this chart.
redis.enabled true Allows opting-out of using Redis for KAS features. Warnings: Redis will become a hard dependency soon, so this key is already deprecated.
resources.requests.cpu 75m GitLab Exporter minimum CPU.
resources.requests.memory 100M GitLab Exporter minimum memory.
service.externalPort 8150 External port (for agentk connections).
service.internalPort 8150 Internal port (for agentk connections).
service.apiInternalPort 8153 Internal port for the internal API (for GitLab backend).
service.loadBalancerIP nil A custom load balancer IP when service.type is LoadBalancer.
service.loadBalancerSourceRanges nil A list of custom load balancer source ranges when service.type is LoadBalancer.
service.kubernetesApiPort 8154 External port to expose proxied Kubernetes API on.
service.privateApiPort 8155 Internal port to expose kas’ private API on (for kas -> kas communication).
serviceAccount.annotations {} ServiceAccount annotations.
serviceAccount.automountServiceAccountToken false Indicates whether or not the default ServiceAccount access token should be mounted in pods.
serviceAccount.create false Indicates whether or not a ServiceAccount should be created.
serviceAccount.enabled false Indicates whether or not to use a ServiceAccount.
serviceAccount.name   Name of the ServiceAccount. If not set, the full chart name is used.
privateApi.secret Autogenerated The name of the secret to use for authenticating with the database.
privateApi.key Autogenerated The name of the key in privateApi.secret to use.
global.kas.service.apiExternalPort 8153 External port for the internal API (for GitLab backend).
service.type ClusterIP Service type.
tolerations [] Toleration labels for pod assignment.
customConfig {} When given, merges the default kas configuration with these values giving precedence to those defined here.
deployment.minReadySeconds 0 Minimum number of seconds that must pass before a kas pod is considered ready.
deployment.strategy {} Allows one to configure the update strategy utilized by the deployment.
deployment.terminationGracePeriodSeconds 300 How much time in seconds a Pod is allowed to spend shutting down after receiving SIGTERM.
priorityClassName   Priority class assigned to pods.

Enable TLS communication

Enable TLS communication between your kas pods and other GitLab chart components, through the global KAS attribute.

Test the kas chart

To install the chart:

  1. Create your own Kubernetes cluster.
  2. Check out the merge request’s working branch.

  3. Install (or upgrade) GitLab with kas enabled by default from your local chart branch: 

    helm upgrade --force --install gitlab . \
  --timeout 600s \
  --set global.hosts.domain=your.domain.com \
  --set global.hosts.externalIP=XYZ.XYZ.XYZ.XYZ \
  --set certmanager-issuer.email=your@email.com

  4. Use the GDK to run the process to configure and use the GitLab agent for Kubernetes: (You can also follow the steps to configure and use the agent manually.)

    1. From your GDK GitLab repository, move into the QA folder: cd qa.

    2. Run the following command to run the QA test: 

      GITLAB_USERNAME=$ROOT_USER
GITLAB_PASSWORD=$ROOT_PASSWORD
GITLAB_ADMIN_USERNAME=$ROOT_USER
GITLAB_ADMIN_PASSWORD=$ROOT_PASSWORD
bundle exec bin/qa Test::Instance::All https://your.gitlab.domain/ -- --tag orchestrated --tag quarantine qa/specs/features/ee/api/7_configure/kubernetes/kubernetes_agent_spec.rb

      You can also customize the agentk version to install with an environment variable: GITLAB_AGENTK_VERSION=v13.7.1

Configuring KEDA

This keda section enables the installation of KEDA ScaledObjects instead of regular HorizontalPodAutoscalers. This configuration is optional and can be used when there is a need for autoscaling based on custom or external metrics.

Most settings default to the values set in the hpa section where applicable.

If the following are true, CPU and memory triggers are added automatically based on the CPU and memory thresholds set in the hpa section:

  • triggers is not set.
  • The corresponding request.cpu.request or request.memory.request setting is also set to a non-zero value.

If no triggers are set, the ScaledObject is not created.

Refer to the KEDA documentation for more details about those settings.

Name Type Default Description
enabled Boolean false Use KEDA ScaledObjects instead of HorizontalPodAutoscalers
pollingInterval Integer 30 The interval to check each trigger on
cooldownPeriod Integer 300 The period to wait after the last trigger reported active before scaling the resource back to 0
minReplicaCount Integer   Minimum number of replicas KEDA will scale the resource down to, defaults to minReplicas
maxReplicaCount Integer   Maximum number of replicas KEDA will scale the resource up to, defaults to maxReplicas
fallback Map   KEDA fallback configuration, see the documentation
hpaName String   The name of the HPA resource KEDA will create, defaults to keda-hpa-{scaled-object-name}
restoreToOriginalReplicaCount Boolean   Specifies whether the target resource should be scaled back to original replicas count after the ScaledObject is deleted
behavior Map   The specifications for up- and downscaling behavior, defaults to hpa.behavior
triggers Array   List of triggers to activate scaling of the target resource, defaults to triggers computed from hpa.cpu and hpa.memory

serviceAccount

This section controls if a ServiceAccount should be created and if the default access token should be mounted in pods.

Name Type Default Description
annotations Map {} ServiceAccount annotations.
automountServiceAccountToken Boolean false Controls if the default ServiceAccount access token should be mounted in pods. You should not enable this unless it is required by certain sidecars to work properly (for example, Istio).
create Boolean false Indicates whether or not a ServiceAccount should be created.
enabled Boolean false Indicates whether or not to use a ServiceAccount.
name String   Name of the ServiceAccount. If not set, the full chart name is used.

affinity

For more information, see affinity.