Gitkube

Gitkube is a tool for building and deploying Docker images on Kubernetes using git push.

After a simple initial setup, users can simply keep git push-ing their repos to build and deploy to Kubernetes automatically.

Gitkube

When should I use gitkube?

Ideal for development where you can push your WIP branch to the cluster to test.
Reference implementation for writing git-based automation on your server. Fork this repo and create your own CRD + controller + git remote hook that can do things on the Kubernetes cluster.

Features:

No dependencies except native tooling (git, kubectl)
Plug and play installation
Simple public key based authentication
RBAC ready - Control access to git remotes using RBAC
Support for namespace based multi-tenancy - Remotes can only deploy to their own namespace
No assumptions about repository structure

Getting started

Gitkube will run on any Kubernetes vendor/distribution AS IS. In case you find any difficulties in the setup, please comment on #33

Install gitkube

Using kubectl

kubectl create -f https://raw.githubusercontent.com/hasura/gitkube/master/manifests/gitkube-setup.yaml
#expose gitkubed service kubectl --namespace kube-system expose deployment gitkubed --type=LoadBalancer --name=gitkubed

Using gitkube CLI (DEPRECATED)

Install Gitkube CLI:

- Linux/MacOS

bash
   curl https://raw.githubusercontent.com/hasura/gitkube/master/gimme.sh | bash

- Windows (using scoop)

scoop install gitkube

Or download the latest release and add it to your PATH.

Use Gitkube CLI to install Gitkube on the cluster:

gitkube install

Workflow

Local dev: User creates a base git repo for the application with Dockerfile and K8s deployment
Setting Remote: User defines a spec for Remote containing the rules for git push
Deploying application: Once a Remote is setup, application can be deployed to K8s using git push <remote> master

Local dev

User should have a git repo with source code and a Dockerfile. User should also create a base K8s deployment for the application.

Setting Remote

A Remote resource consists of 3 parts:

authorizedKeys: List of ssh-keys for authorizing git push.
registry: Details of docker registry where images are pushed post-build.
deployments: Spec for building docker image and updating corresponding K8s deployment.

Here is a typical spec for a Remote:

apiVersion: gitkube.sh/v1alpha1
kind: Remote
metadata:
  name: sampleremote
  namespace: default
spec:
Insert ssh-keys for allowing users to git push
  authorizedKeys:
  - "ssh-rsa your-ssh-public-key"
Provide registry details: https://github.com/hasura/gitkube/blob/master/docs/registry.md
  registry:
    url: "docker.io/user"
    credentials:
      secretRef: regsecret                # Name of docker-registry secret
Define deployment rules
  deployments:
  - name: www                             # Name of K8s deployment which is updated on git push
    containers: 
    - name: www                           # Name of container in the deployment which is built during git push
      path: example/www                   # Docker build context path in the git repo
      dockerfile: example/www/Dockerfile  # Location of Dockerfile for the source code

Deploying application

Once a Remote is created, it gets a git remote URL which you can find in its status spec

$ kubectl get remote sampleremote -o yaml
...
status:
  remoteUrl: ssh://default-sampleremote@35.225.226.96/~/git/default-sampleremote
  remoteUrlDesc: ""

Add the generated remoteUrl in git

$ git remote add sampleremote ssh://default-sampleremote@35.225.226.96/~/git/default-sampleremote

And finally, git push

$ git push sampleremote master

More examples

Follow this example repo for more workflows with gitkube.

How it works

Gitkube has three components:

Remote: Custom resource defined by a K8s CRD
gitkube-controller: Controller that manages Remote objects and propogates changes to gitkubed
gitkubed: Git host that builds docker image from the repo and rolls out deployment