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Public OCI Repositories

Updated Aug 23, 2022 ·

Overview​

This guide shows how to use public and private OCI Helm repositories with Flux CD to install applications like MySQL and Apache on Kubernetes clusters.

A few notes:

  • I'm running the lab in a Windows 10 machine
  • Tools used: Docker Desktop, WSL2
  • A Kubernetes cluster is using kind
  • Flux is running inside the Kubernetes cluster
  • Gitlab is used for the Git repositories

Pre-requisites​

Project Directory​

info

Make sure to go through the pre-requisites before proceeding to the next steps

If you followed the steps in setting up Flux, your project directory should have the following files:

$ tree
.
├── README.md
└── clusters
    └── dev
        └── flux-system
            ├── gotk-components.yaml
            ├── gotk-sync.yaml
            ├── kustomization.yaml

3 directories, 6 files

To organize the manifests, we will create folders for each lab, along with their respective kustomization.yaml file.

For this lab, create the helm-repos-oci-mysql directory:

mkdir clusters/dev/helm-repos-oci-mysql

Open Container Initiative (OCI)​

Open Container Initiative (OCI) defines a standard way to share software like container images and Helm charts.

  • Uses digests for better security
  • Can be used by many tools

OCI registries support stronger security features than basic HTTP Helm repos and are becoming a common choice for hosting Helm charts.

Using a Public OCI Helm Repository​

This section shows how to deploy MySQL using a public OCI Helm chart.

First, create a new branch for your work:

## Make sure main branch is updated 
git checkout main 
git pull

## Create new branch
git checkout -b public-oci

Prepare the Manifests​

Add a new HelmRepository file and set the type to oci and provide the OCI URL. This lets Flux CD know that the chart source is an OCI registry, not a regular HTTP one.

## clusters/dev/helm-repos-oci-mysql/bitnami-oci.yaml
apiVersion: source.toolkit.fluxcd.io/v1beta2
kind: HelmRepository
metadata:
  name: mysql
  namespace: default
spec:
  type: oci
  interval: 5m0s
  url: oci://registry-1.docker.io/bitnamicharts

Now we install the MySQL chart from the public OCI repo. Create a HelmRelease file for MySQL

## clusters/dev/helm-repos-oci-mysql/mysql-release.yaml
apiVersion: helm.toolkit.fluxcd.io/v2beta1
kind: HelmRelease
metadata:
  name: mysql
  namespace: default
spec:
  interval: 5m
  chart:
    spec:
      chart: mysql
      version: '9.10.9'
      interval: 1m
      sourceRef:
        kind: HelmRepository
        name: mysql
        namespace: default
  values:
    auth:
      username: "johnsmith"
      password: "mypass"
      database: "testdb"

Add the files to kustomization.yaml:

## clusters/dev/helm-repos-oci-mysql/kustomization.yaml
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- mysql-release.yaml
- bitnami-oci.yaml

Commit and push:

git add -A
git commit -m 'Add the Bitnami OCI repository and the MySQL Helm
release'
git push --set-upstream origin public-oci

After pushing, merge the changes to the main branch. Since we are using Gitlab in this setup, login to the Gitlab UI and go to the repository. We should see a Create merge request at the top. Click it and provide a title and description to the merge request in the next step.

In a typical team setting, developers create merge requests which are then reviewed and approved by other team members. For this lab, you can go ahead and click Approve and Merge directly.

Trigger Reconciliation​

Once changes are merged, tell FluxCD to sync the state.

flux reconcile kustomization flux-system --with-source

Verify deployment:

$ kubectl get helmrelease  
NAME                  AGE   READY   STATUS
mysql                 16m   True    Helm install succeeded for release default/mysql.v1 with chart mysql@9.10.9

$ kubectl get helmrepo
NAME              URL                                        AGE    READY   STATUS
mysql             oci://registry-1.docker.io/bitnamicharts   7m9s

$ kubectl get po
NAME                                   READY   STATUS    RESTARTS         AGE
mysql-0                                1/1     Running   0                3m57s

Access the MySQL Pod​

You can check the pod and access the database like this:

kubectl get pods
kubectl exec -it mysql-0 -- mysql -u johnsmith -p testdb

This shows the MySQL chart from the public OCI repo is working correctly with Flux CD.

mysql> status
--------------
mysql  Ver 8.0.34 for Linux on x86_64 (Source distribution)