Peribolos allows the org settings, teams and memberships to be declared in a yaml file. GitHub is then updated to match the declared configuration.

See the kubernetes/org repo, in particular the merge and parts of that repo for this tool in action.

Peribolos was the subject of a KubeCon talk: How Kubernetes Uses GitOps to Manage GitHub Communities at Scale


A peribolos is a wall that encloses a court in Greek/Roman architecture.

Org configuration

Extend the primary prow config.yaml document to include a top-level orgs key that looks like the following:

    # org settings
    company: foo
    email: foo
    name: foo
    description: foo
    has_organization_projects: true
    has_repository_projects: true
    default_repository_permission: read
    members_can_create_repositories: false

    # org member settings
    - anne
    - bob
    - carl

    # team settings
        # team config
        description: people working on node backend
        privacy: closed
        - backend  # If a backend team exists, rename it to node

        # team members
        - anne
        - jane
        repos: # Ensure the team has the following permissions levels on repos in the org
          some-repo: admin
          other-repo: read

This config will:

  • Ensure the org settings match the following:
    • Set the company, email, name and descriptions fields for the org to foo
    • Allow projects to be created at the org and repo levels
    • Give everyone read access to repos by default
    • Disallow members from creating repositories
  • Ensure the following memberships exist:
    • anne and bob are members, carl is an admin
  • Configure the node and another-team in the following manner:
    • Set node’s description and privacy setting.
    • Rename the backend team to node
    • Add anne as a member and jane as a maintainer to node
    • Similar things for another-team (details elided)
  • Ensure that the team has admin rights to some-repo, read access to other-repo and no other privileges

Note that any fields missing from the config will not be managed by peribolos. So if description is missing from the org setting, the current value will remain.

For more details please see GitHub documentation around edit org, update org membership, edit team, update team membership.

Initial seed

Peribolos can dump the current configuration to an org. For example you could dump the kubernetes org do the following:

$ go run ./cmd/peribolos --dump kubernetes-sigs --github-token-path ~/github-token | tee ~/current.yaml
INFO: Build completed successfully, 1 total action
{"client":"github","component":"peribolos","level":"info","msg":"ListOrgMembers(kubernetes-sigs, admin)","time":"2018-09-28T13:17:42-07:00"}
{"client":"github","component":"peribolos","level":"info","msg":"ListOrgMembers(kubernetes-sigs, member)","time":"2018-09-28T13:17:43-07:00"}
{"client":"github","component":"peribolos","level":"info","msg":"ListTeamMembers(2671356, maintainer)","time":"2018-09-28T13:17:46-07:00"}
{"client":"github","component":"peribolos","level":"info","msg":"ListTeamMembers(2671356, member)","time":"2018-09-28T13:17:46-07:00"}
- calebamiles
- cblecker
- etc
company: ""
default_repository_permission: read
description: Org for Kubernetes SIG-related work
email: ""
has_organization_projects: true
has_repository_projects: true
location: ""
- ameukam
- amwat
- ant31
- etc
    description: admin access to application
    - kow3ns
    - mattfarina
    - prydonius
    privacy: closed
    description: admin permission for architecture-tracking
    - jdumars
    - bgrant0607
    privacy: closed
  # etc

Open ~/current.yaml and then delete any metadata you don’t want peribolos to manage (such as billing_email, or all the teams, etc).

Apply this config in dry-run mode to see what would happen (hopefully nothing since you just created it):

$ go run ./cmd/peribolos --config-path ~/current.yaml --github-token-path ~/github-token # --confirm

{"client":"github","component":"peribolos","level":"info","msg":"ListOrgMembers(kubernetes-sigs, admin)","time":"2018-09-27T23:07:13Z"}
{"client":"github","component":"peribolos","level":"info","msg":"ListOrgMembers(kubernetes-sigs, member)","time":"2018-09-27T23:07:14Z"}


In order to mitigate the chance of applying erroneous configs, the peribolos binary includes a few safety checks:

  • --required-admins= - a list of people who must be configured as admins in order to accept the config (defaults to empty list)
  • --min-admins=5 - the config must specify at least this many admins
  • --require-self=true - require the bot applying the config to be an admin.

These flags are designed to ensure that any problems can be corrected by rerunning the tool with a fixed config and/or binary.

  • --maximum-removal-delta=0.25 - reject a config that deletes more than 25% of the current memberships.

This flag is designed to protect against typos in the configuration which might cause massive, unwanted deletions. Raising this value to 1.0 will allow deleting everyone, and reducing it to 0.0 will prevent any deletions.

  • --confirm=false - no github mutations will be made until this flag is true. It is safe to run the binary without this flag. It will print what it would do, without actually making any changes.

See go run ./cmd/peribolos --help for the full and current list of settings that can be configured with flags.