/flux-operator

Operator for creating and managing Weaveworks Flux, helm-operator, and Tiller instances

Primary LanguageGoApache License 2.0Apache-2.0

Operator for creating and managing instances of Weaveworks flux, helm-operator and tiller, the cluster component of Helm.

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Use-cases:

  • Doing GitOps without a monorepo. You can easily split your manifests into repos per team, project or namespace.
  • Simplify the deployment of your Flux, Tiller, and helm-operator instances.
  • Easily manage Flux RBAC policies to prevent any single Flux instance from having access to the entire cluster.
  • Use Helm without violating your RBAC policies.

Installation

Overview

Flux-operator uses Custom Resource Definitions to declare what instances of Flux should exist in a cluster.

The flux-operator allows creating the Flux Custom Resource Definition with either a Cluster scope or a Namespaced scope.

If the CRD is deployed with Cluster scope, then Flux instances will be created in the namespace specified in the Flux spec, for example, the following Flux would be created in the default namespace:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
spec:
  namespace: default
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator

If the CRD is deployed at the Namespaced scope, then the Flux instances will be created in the same namespace as the Flux CR, for example, to create a Flux instance in default, you would do:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
  namespace: default
spec:
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator

In general, if users are creating Fluxes, it is best to create it Namespaced, if you are centrally controlling Fluxes, then Cluster scope may be better.

Using fluxopctl

The easiest way to install flux-operator is with fluxopctl. Install it:

go install github.com/justinbarrick/flux-operator/cmd/fluxopctl

You can then setup your cluster:

fluxopctl |kubectl apply -f -

This will setup namespaced flux-operator.

The default settings should be sufficient for most users, but flux-operator settings can be tuned via command line arguments.

For example, to install flux-operator at the cluster-scope, run:

fluxopctl -cluster |kubectl apply -f -

See: fluxopctl -help for a full list of arguments.

Manual

Namespaced scope

Namespaced scope is recommended for most users:

kubectl apply -f deploy/flux-operator-namespaced.yaml

Cluster scope

However, if you have a central control for your Flux CRs, then it may make sense to deploy your CRs Cluster scoped:

kubectl apply -f deploy/flux-operator-cluster.yaml

Creating a Flux instance

To create a Flux instance, create a Flux CR:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
  namespace: default
spec:
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  role:
    enabled: true
  args:
    connect: "ws://fluxcloud/"

This will create a flux pod called flux-example in the default namespace.

Settings in the Flux spec:

  • gitUrl: the URL to git repository to clone (required).
  • gitBranch: the git branch to use (default: master).
  • gitPath: the path with in the git repository to look for YAML in (default: .).
  • gitPollInterval: the frequency with which to fetch the git repository (default: 5m0s).
  • syncInterval: the frequency with which to sync the manifests in the repository to the cluster (default: 5m0s).
  • gitSecret: the Kubernetes secret to use for cloning, if it does not exist it will be generated (default: flux-$name-git-deploy or $GIT_SECRET_NAME).
  • fluxImage: the image to use for flux (default: quay.io/weaveworks/flux or $FLUX_IMAGE).
  • fluxVersion: the version to use for flux (default: 1.4.0 or $FLUX_VERSION).
  • resources: resource limits to set on the flux pod.
  • clusterRole.enabled: if enabled, a cluster role will be assigned to the service account (default: false).
  • clusterRole.rules: the list of rbac rules to use (default: full access to all resources).
  • role.enabled: if enabled, a role will be assigned to the service account (default: false).
  • role.rules: the list of rbac rules to use (default: full access to all resources in the namespace).
  • tiller.enabled: whether or not to deploy a tiller instance in the same namespace (default: false).
  • tiller.tillerImage: the image to use with tiller (default: gcr.io/kubernetes-helm/tiller or $TILLER_IMAGE)
  • tiller.tillerVersion: the image version to use with tiller (default: v2.9.1 or $TILLER_VERSION)
  • args: a map of args to pass to flux without -- prepended.
  • helmOperator.enabled: whether or not to deploy a helm-operator instance in the same namespace (default: false).
  • helmOperator.helmOperatorImage: the image to use with helm-operator (default: quay.io/weaveworks/helm-operator or $HELM_OPERATOR_IMAGE).
  • helmOperator.helmOperatorVersion: the image version to use with helm-operator (default: master-a61c1d5 or $HELM_OPERATOR_VERSION).
  • helmOperator.resources: resource limits to set on the helm-operator pod.
  • helmOperator.chartPath: the chart path to use with Helm Operator (default: .).
  • helmOperator.gitPollInterval: the frequency with which to sync Git (default: the flux gitPollInterval or, if not set, 3m0s).
  • helmOperator.chartsSyncInterval: the frequency with which to sync the charts (default: the flux syncInterval or, if not set, 3m0s).
  • helmOperator.gitUrl: the URL of the git repository to use if it is different than the primary flux gitUrl.
  • fluxCloud.enabled: if set to true, a fluxcloud instance will be deployed.
  • fluxCloud.githubUrl: the HTTP URL to the Github repository.
  • fluxCloud.slackUrl: the slack webhook to use.
  • fluxCloud.slackChannel: the slack channel to send messages to.
  • fluxCloud.slackUsername: the slack username to use when sending messages (default: Flux Deployer).
  • fluxCloud.slackIconEmoji: the icon emoji to use with slack (default: :star-struck:).
  • fluxcloud.fluxCloudImage: the fluxcloud image to use (default: justinbarrick/fluxcloud).
  • fluxcloud.fluxCloudVersion: the fluxcloud image to use (default: master-89f5fec).
  • namespace: if the Flux CRD is cluster-scpoed, then the namespace to deploy Flux to is specified in the Flux spec - if the Flux CRD is namespaced, then this namespace is ignored and the Flux CR's actual namespace is used instead.

You can also override some of the defaults by setting environment variables on the operator itself:

  • GIT_SECRET_NAME: the git secret name to use.
  • FLUX_IMAGE: the default image to use for flux.
  • FLUX_VERSION: the default version to use for flux.
  • HELM_OPERATOR_IMAGE: the default image to use for helm-operator.
  • HELM_OPERATOR_VERSION: the default version to use for helm-operator.
  • MEMCACHED_IMAGE: the default memcached image.
  • MEMCACHED_VERSION: the default memcached version.
  • TILLER_IMAGE: the default tiller image.
  • TILLER_VERSION: the default tiller version.
  • FLUX_NAMESPACE: if set, the namespace to watch instead of watching all namespaces for Flux CRs - only has an effect if the Flux CRD is namespaced.
  • DISABLE_ROLES: if set to true, prevent users from assigning Fluxes roles.
  • DISABLE_CLUSTER_ROLES: if set to true, prevent users from assigning Fluxes cluster roles (only the default, list all namespaces permission is granted).

Git SSH key

If you already have an SSH key to use with flux, then add it as a secret to Kubernetes:

kubectl create secret generic mysecret --from-file=identity=/home/user/.ssh/id_rsa

You can then reference the secret as gitSecret: mysecret in your Flux YAML.

To get the SSH public key from the SSH key you are using run:

ssh-keygen -y -f <(kubectl get secret -o 'go-template={{ .data.identity }}' flux-example-git-deploy |base64 -d)

You can then paste this into your Github deploy keys.

Creating a Tiller instance

The flux-operator can also deploy Tiller with Flux into your namespace. The Tiller instance uses the same service account as Flux.

To enable, set tiller.enabled to true:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
spec:
  namespace: default
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  role:
    enabled: true
  tiller:
    enabled: true

You can now securely use Helm in this namespace:

helm --tiller-namespace default ls
helm --tiller-namespace default install stable/memcached

Migrating Tiller

If you already have a default Tiller installation, you can easily start managing it with the flux-operator:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: flux
spec:
  namespace: kube-system
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  clusterRole:
    enabled: true
  tiller:
    enabled: true

Save this as flux.yaml, delete the old tiller-deploy and apply the new one:

kubectl delete deployment -n kube-system tiller-deploy
kubectl apply -f ./flux.yaml

You should now be able to run helm ls and see all of your old deployments.

Helm Operator

Along with Tiller, it is possible to deploy the Helm Operator. The Helm operator currently requires access to all namespaces, so a clusterRole must be set. This means you should currently only enable the Helm Operator on one flux.

If Tiller does not already exist in the namespace, also set tiller.enabled: true.

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
  namespace: default
spec:
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  clusterRole:
    enabled: true
  tiller:
    enabled: true
  helmOperator:
    enabled: true

You should then be able to create a FluxHelmRelease. See the helm-operator example for more information.

Slack

Flux operator supports Slack notifications of Flux activity via fluxcloud.

To enable, create a Slack incoming webhook.

Then add the following to your Flux:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
  namespace: default
spec:
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  fluxCloud:
    enabled: true
    githubUrl: https://github.com/justinbarrick/flux-operator
    slackUrl: YOUR_WEBHOOK
    slackChannel: "#mychannel"

RBAC

By default, a service account is created and given "get", "watch", "list", permissions on all namespaces and assigned to the flux pod. The service account is called flux-$fluxname.

You can enable both a role and a cluster role on the service account.

To enable a cluster role, set clusterRole.enabled. The default cluster role created will grant access to all resources in the cluster.

To enable a role, set role.enabled. The default role created will grant access to all resources in the namespace.

You can also set custom RBAC rules by setting role.rules or clusterRole.rules:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
  namespace: default
spec:
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  clusterRole:
    enabled: true
    rules:
      - apiGroups: ['*']
        resources: ['*']
        verbs: ['*']
      - nonResourceURLs: ['*']
        verbs: ['*']

See Kubernetes role documentation for more information.

Using environment variables, it is also possible to disable assigning roles (DISABLE_ROLES=true) and disabling cluster roles (DISABLE_CLUSTER_ROLES=true).

Flux currently does not support having access to only a single namespace, so if you want to restrict Flux to a single namespace, set k8s-namespace-whitelist to the namespace:

apiVersion: flux.codesink.net/v1alpha1
kind: Flux
metadata:
  name: example
  namespace: default
spec:
  gitUrl: ssh://git@github.com/justinbarrick/flux-operator
  role:
    enabled: true
  args:
    k8s-namespace-whitelist: default

Contributing

If you are fixing a bug or adding a feature, please open a ticket describing it and reference it in your commit message.

Please add a test for your change :)

Testing

Flux-operator is unit tested:

make test

And integration tested using minikube in drone. You can run the tests locally using minikube and the integration-test.sh script:

minikube start
eval $(minikube docker-env)
export SSH_KEY="$(cat /path/to/ssh/deploy/key/for/repository)"
make build
./integration-test.sh

Note: you will need to fork this repository and add your own deploy keys to the fork since flux requires read/write access to a repository.