Genoa

WIP: Opinionated webhook based GitOps controller that installs and manages helm (v3) releases from configured github/gitlab repositories

Genoa does two important things:

• Allows you to manage your helm releases in a GitOps fashion using a custom resource definitions of the chart name, version, and values
• Responds to git webhook invocations when those resource definitions change (gitops)

Installing the Chart

You can install the chart with the release name genoa as below.

From this repository, create your own genoa.values.yaml file and install the chart:

$ kubectl create ns genoa
$ helm upgrade genoa charts/genoa --install --namespace=genoa --values=genoa.values.yaml

NOTE: For custom helm repositories, you need to tell Genoa about them with the config.helmRepos in your Genoa values.yaml file. The can be viewed in repositories.yaml file in this repository or in chart values file: .Values.config.helmRepos

Using Genoa

After installing the Genoa helm chart it creates releases.coveros.apps.com as a CRD in the cluster. You use Genoa by creating release CRs that describe the helm releases you want to manage.

See ./sample-releases for examples of release CRs.

See api/v1alpha1/release_types.go for a full spec of the values you can put in a release.

Side note: Genoa can adopt existing helm releases by simply building a release.yaml to represent the current chart and values

Annotations that control the release:

  annotations:
    "coveros.apps.genoa/autoDeleteNamespace": "true" # DISABLED. delete namespace when release is deleted
    "coveros.apps.genoa/follow-git-branch": "master" # which branch this follows for webhook
    "coveros.apps.genoa/notification-channel-id": "YOUR_SLACK_CHANNEL_ID" # who to notify

Important fields for every release:

  chart: stable/jenkins # req: what chart
  version: 2.4.1        # req: pin a version
  values: # values files for the helm chart
    master:
      adminUser: admin
      adminPassword: secRet!
    persistence:
      enabled: false

TODO:

• How to set up slack notifications with "slack app oauth token"

Registering the webhook

To enable Gitops behavior, you need to set your Git server with a webhook to invoke the controller when your helm release CRs change in Git. Your genoa.values.yaml file needs to include these things:

config:
  github: # example for github
     enabled: true
     accessToken: xxxxxxxxx # user or deploy key as access token to authenticate to github to fetch code
     webhookSecret: abc123xyz # generate this from a ruby -rsecurerandom -e 'puts SecureRandom.hex(20)'
     deployDir: /deploy # the directory where you have your release.yaml files live in the repo

Create these, then install the chart and it will tell you what to register in github as part of the notes.

Use cases for genoa

Need to think through how you could do complicated things.

• Simple case where you have a /deploy directory which notifices single cluster for helm release changes
• Case where you have directories representing individual clusters (or even namespaces)
• Case where you have separate repositories representing clusters or namespaces
• Complicated case where /global-deploy directory notifies multiple clusters that a central helm release has changed and therefore should be deployed to multiple clusters. Could use CR branch tags to test on a branch first in a particular cluster, then use the master branch to roll out to all clusters.

Contributing

Pre-req:

• golang 1.14.1
• kube builder KubeBuilderVersion:“2.3.1”,

Building:

Set your context to something harmless (docker-for-desktop)

make local-build
...
go mod tidy
go: downloading google.golang.org/appengine v1.6.5
...