Kubernetes Developer experience example

Requirements

docker
k3d >v4.x.x
skaffold >v1.2x.x

Install k3d

Install k3d from the release page here required version > v4.x.x

$ export KUBECONFIG=~/.kube/skaffold
$ k3d cluster create staging -p "8081:80@loadbalancer"

Check that the cluster is available

kubectl get nodes
NAME                   STATUS   ROLES                  AGE   VERSION
k3d-staging-server-0   Ready    control-plane,master   71m   v1.21.1+k3s1

Local dev

We use a combination of docker commands for formatting and linting, then skaffold is used to

build the image
test image built with structure-tests
deploy on a local k3d cluster

Code formatting

make format

Building the image

make build

Testing the application

make dev

This action will use skaffold to build the image then tests are run and finally the application is exposed.

Skaffold under the hood

Note that skaffold detects automatically that this is a local k3d cluster as the cluster name starts with k3d-(.*) That means that, during the dev step, the image would be copied locally to the local k8s instance. The image won't be pushed in order to speed up the feedback loop

skaffold dev
Listing files to watch...
 - smana/helloworld
Generating tags...
 - smana/helloworld -> smana/helloworld:0cbeeae-dirty
Checking cache...
 - smana/helloworld: Not found. Building
Found [k3d-default] context, using local docker daemon.
Building [smana/helloworld]...
...
Loading images into k3d cluster nodes...
 - smana/helloworld:d70199b9aa0a7e6a38...

Another trick helps speeding up the feedback: some files don't require to rebuild the whole image. We make use of the "File Sync" in order to copy the files to the running container.

excerpt of the skaffold.yaml

build:
  artifacts:
    - image: smana/helloworld
      sync:
        infer: ["**/*.html"]

GitOps workflow

This is a simple web applications to demonstrate a GitOps workflow using Github Actions and Flux v2.

Deploy using Flux

This is a good practice to separate the code of our application and the config to define how it is deployed. The GitOps workflow is defined if the repository flux-demo

Release a new version

The git branch format is important for the release workflow. Here are the prefixes to prepend to the branch names:

Bug fixes: fix/
Features: feat/
Maintenance changes: chore/
Documentation changes: doc/

By default it will create a draft release with a patch tag (eg. v0.1.1) It is possible to add a label minor or major to control the version.

Smana / gitops-demo