Deploy Helm OCI charts with ArgoCD

In this post, I’ll describe how to deploy OCI Helm chart using ArgoCD.

In our projects, we use Harbor both registries for docker and Helm Charts. Currently, we using Chartmuseum but in the Harbor release v2.2.0 was announced that it will be deprecated

Researching was not so long, and we found that Helm 3 supports OCI for package distribution. Also, the OCI-compatible registry, provided by Harbor since version 2.0.0

Helm 3: Commands for working with registries

Enable OCI support

$ export HELM_EXPERIMENTAL_OCI=1

Login

$ helm registry login -u <user_name> myregistry.com

Password:
Login succeeded

List all saved charts

$ helm chart list

REF    NAME  VERSION   DIGEST  SIZE   CREATED
myregistry.com/helm-charts/simple-chart:1.0.0  simple-chart   0.1.0   a8de052 4.1 KiB     8 hours
myregistry.com/helm-charts/simple-chart:1.1.2  simple-chart   0.1.0   c2afe75 4.1 KiB     19 minutes

Save a chart directory to the local cache

$ helm chart save simple-chart myregistry.com/helm-charts/simple-chart:1.1.2
ref:     myregistry.com/helm-charts/simple-chart:1.1.2
digest:  43f18e1ee4df7b58b7094730566fb81964eb07a9d4d8fb
size:    4.1 KiB
name:    simple-chart
version: 0.1.0
1.1.2: saved

Push a chart to remote

$ helm chart push myregistry.com/helm-charts/simple-chart:1.1.2
The push refers to repository [myregistry.com/helm-charts/simple-chart]
ref:     myregistry.com/helm-charts/simple-chart:1.1.2
digest:  3f0e3243f18e1ee4df7b58b7094730566fb81964eb07a9d4d8fb
size:    4.1 KiB
name:    simple-chart
version: 0.1.0
1.1.2: pushed to remote (1 layer, 4.1 KiB total)

Use OCI Helm Chart

Create an empty directory with Chart.yaml and values.yaml files and push to Git repo

Chart.yaml

apiVersion: v2
name: simple-chart
description: Simple Chart
type: application
version: 0.1.0
dependencies:
- name: simple-chart
  version: "1.1.2"
  repository: "oci://myregistry.com/helm-charts"

values.yaml

simple-chart:
  env:
    myFirstEnv: 'SimpleEnv'

Build dependency and deploy Helm Chart

Go to Chart directory and run commands:

$ helm dependency build
Update Complete. ⎈Happy Helming!⎈
Saving 1 charts
Downloading simple-chart from repo oci://myregistry.com/helm-charts
1.1.2: Pulling from myregistry.com/helm-charts/simple-chart
Deleting outdated charts

Deploy application:

$ helm install my-application .

NAME: my-application
LAST DEPLOYED: Mon Apr 19 22:39:03 2021
NAMESPACE: default
STATUS: deployed
REVISION: 1
TEST SUITE: None

Deploy an application with ArgoCD

Create helm repo with cli

argocd repo add myregistry.com --type helm --name registry --enable-oci --username <username> --password <password>

Create helm repo with yaml

This example based on the official ArgoCD Helm Chart

Create secret with Login and Password from Helm registry

apiVersion: v1
kind: Secret
metadata:
  name: argocd-helm-oci
data:
  username: username|base64 
  password: password|base64
type: Opaque

Apply secret to Kubernetes:

$ kubectl apply -f secret.yaml

Edit values.yaml

Add repository:

server:
  config:
    repositories: |
      - type: helm
        name: registry
        url: myregistry.com
        enableOci: true
        usernameSecret:
          name: argocd-helm-oci
          key: username
        passwordSecret:
          name: argocd-helm-oci
          key: password

Add application:

server:
...
   additionalApplications:
     - name: my-application
       project: default
       source:
         path: .
         repoURL: 'https://git.com/myrepo/simple-chart.git'
         targetRevision: HEAD
         helm:
           valueFiles:
             -  values.yaml
       destination:
         namespace: default
         server: 'https://kubernetes.default.svc'
       syncPolicy:
         automated:
           prune: true
           selfHeal: true

Install ArgoCD

$ helm install -n argocd argocd .