Kubernetes Agent configuration repository (PREMIUM)

• Introduced in GitLab Premium 13.7.
• Introduced in GitLab 13.11, the Kubernetes Agent became available on GitLab.com.
• Introduced in GitLab 14.0, the resource_inclusions and resource_exclusions attributes were removed.

WARNING: This feature might not be available to you. Check the version history note above for details.

The GitLab Kubernetes Agent integration supports hosting your configuration for multiple GitLab Kubernetes Agents in a single repository. These agents can be running in the same cluster or in multiple clusters, and potentially with more than one Agent per cluster.

The Agent bootstraps with the GitLab installation URL and an authentication token, and you provide the rest of the configuration in your repository, following Infrastructure as Code (IaaC) best practices.

A minimal repository layout looks like this, with my_agent_1 as the name of your Agent:

|- .gitlab
    |- agents
       |- my_agent_1
          |- config.yaml

Synchronize manifest projects

Your config.yaml file contains a gitops section, which contains a manifest_projects section. Each id in the manifest_projects section is the path to a Git repository with Kubernetes resource definitions in YAML or JSON format. The Agent monitors each project you declare, and when the project changes, GitLab deploys the changes using the Agent.

To use multiple YAML files, specify a paths attribute in the gitops.manifest_projects section.

gitops:
  # Manifest projects are watched by the agent. Whenever a project changes,
  # GitLab deploys the changes using the agent.
  manifest_projects:
    # No authentication mechanisms are currently supported.
    # The `id` is a path to a Git repository with Kubernetes resource definitions
    # in YAML or JSON format.
  - id: gitlab-org/cluster-integration/gitlab-agent
    # Namespace to use if not set explicitly in object manifest.
    default_namespace: my-ns
    # Paths inside of the repository to scan for manifest files.
    # Directories with names starting with a dot are ignored.
    paths:
      # Read all .yaml files from team1/app1 directory.
      # See https://github.com/bmatcuk/doublestar#about and
      # https://pkg.go.dev/github.com/bmatcuk/doublestar/v2#Match for globbing rules.
    - glob: '/team1/app1/*.yaml'
      # Read all .yaml files from team2/apps and all subdirectories
    - glob: '/team2/apps/**/*.yaml'
      # If 'paths' is not specified or is an empty list, the configuration below is used
    - glob: '/**/*.{yaml,yml,json}'
    # Reconcile timeout defines whether the applier should wait
    # until all applied resources have been reconciled, and if so,
    # how long to wait.
    reconcile_timeout: 3600s # 1 hour by default
    # Dry run strategy defines whether changes should actually be performed,
    # or if it is just talk and no action.
    # https://github.com/kubernetes-sigs/cli-utils/blob/d6968048dcd80b1c7b55d9e4f31fc25f71c9b490/pkg/common/common.go#L68-L89
    # Can be: none, client, server
    dry_run_strategy: none # 'none' by default
    # Prune defines whether pruning of previously applied
    # objects should happen after apply.
    prune: true # enabled by default
    # Prune timeout defines whether we should wait for all resources
    # to be fully deleted after pruning, and if so, how long we should
    # wait.
    prune_timeout: 3600s # 1 hour by default
    # Prune propagation policy defines the deletion propagation policy
    # that should be used for pruning.
    # https://github.com/kubernetes/apimachinery/blob/44113beed5d39f1b261a12ec398a356e02358307/pkg/apis/meta/v1/types.go#L456-L470
    # Can be: orphan, background, foreground
    prune_propagation_policy: foreground # 'foreground' by default
    # InventoryPolicy defines if an inventory object can take over
    # objects that belong to another inventory object or don't
    # belong to any inventory object.
    # This is done by determining if the apply/prune operation
    # can go through for a resource based on the comparison
    # the inventory-id value in the package and the owning-inventory
    # annotation in the live object.
    # https://github.com/kubernetes-sigs/cli-utils/blob/d6968048dcd80b1c7b55d9e4f31fc25f71c9b490/pkg/inventory/policy.go#L12-L66
    # Can be: must_match, adopt_if_no_inventory, adopt_all
    inventory_policy: must_match # 'must_match' by default

Using multiple manifest projects

Storing Kubernetes manifests in more than one repository can be handy, for example:

• You may store manifests for different applications in separate repositories.
• Different teams can work on manifests of independent projects in separate repositories.

To use multiple repositories as the source of Kubernetes manifests, specify them in the list of manifest_projects in your config.yaml:

gitops:
  manifest_projects:
  - id: group1/project1
  - id: group2/project2

Note that repositories are synchronized concurrently and independently from each other, which means that, ideally, there should not be any dependencies shared by these repositories. Storing a logical group of manifests in a single repository may work better than distributing it across several repositories.

You cannot use a single repository as a source for multiple concurrent synchronization operations. If such functionality is needed, you may use multiple agents reading manifests from the same repository.

Ensure not to specify "overlapping" globs to avoid synchronizing the same files more than once. This is detected by the GitLab Kubernetes Agent and leads to an error.

INCORRECT - both globs match *.yaml files in the root directory:

gitops:
  manifest_projects:
  - id: project1    
    paths:
    - glob: '/**/*.yaml'
    - glob: '/*.yaml'

CORRECT - single globs matches all *.yaml files recursively:

gitops:
  manifest_projects:
  - id: project1    
    paths:
    - glob: '/**/*.yaml'

Surface network security alerts from cluster to GitLab

The GitLab Agent provides an integration with Cilium. To integrate, add a top-level cilium section to your config.yml file. Currently, the only configuration option is the Hubble relay address:

cilium:
  hubble_relay_address: "<hubble-relay-host>:<hubble-relay-port>"

If your Cilium integration was performed through GitLab Managed Apps, you can use hubble-relay.gitlab-managed-apps.svc.cluster.local:80 as the address:

cilium:
  hubble_relay_address: "hubble-relay.gitlab-managed-apps.svc.cluster.local:80"

Debugging

To debug the cluster-side component (agentk) of the GitLab Kubernetes Agent, set the log level according to the available options:

• off
• warning
• error
• info
• debug

The log level defaults to info. You can change it by using a top-level observability section in the configuration file, for example:

observability:
  logging:
    level: debug