ArgoCD

Why Argo?

• Using the k8s operator pattern for deployments means that it will reconcile differences between source control and the cluster
• GitOps is pretty cool, but not actually required if you don’t want to!
• Improved cluster recovery and MTTR. Don’t redeploy every app, just ArgoCD and it will reconcile the rest!

Getting started

High level requirements

• A Kubernetes cluster. I’m going to use a local k3s cluster, created with k3d
• A repo of your choosing, with a manifest/source code/etc.
• Basic command line knowledge
• A web browser

That’s about it! (I think)

BTW, this is based on the official getting started guide here.

The cluster

Run the following, it will create a namespace and apply the (non-HA) ArgoCD manifest.

kubectl create namespace argocd
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

Install the latest stable version of the argocd CLI. Instructions for other platforms are here.

VERSION=$(curl -L -s https://raw.githubusercontent.com/argoproj/argo-cd/stable/VERSION)
curl -sSL -o argocd-linux-amd64 https://github.com/argoproj/argo-cd/releases/download/v$VERSION/argocd-linux-amd64
sudo install -m 555 argocd-linux-amd64 /usr/local/bin/argocd
rm argocd-linux-amd64

Port forward so we don’t have to externally expose the service!

kubectl port-forward svc/argocd-server -n argocd 8080:443

Browse to localhost:8080. Credentials are admin and the password can be found at:

argocd admin initial-password -n argocd

or, if you want to do this the old fashioned way, run the following:

k -n argocd get secret argocd-initial-admin-secret -o yaml | yq .data.password -r | base64 -d

Now you’re in!

GitHub detour

Now we need a repo with a manifest. Example repo is public and available here.

Creating the app in ArgoCD

Go back to localhost:8080. You should be able to create a new app now.

Click “NEW APP” and fill in the settings. Here’s the YAML from my example:

project: default
source:
  repoURL: https://github.com/nwber/argo-example
  path: k8s
  targetRevision: HEAD
destination:
  server: https://kubernetes.default.svc
  namespace: nginx
syncPolicy:
  automated:
    prune: true
    selfHeal: true
    enabled: true
  syncOptions:
    - CreateNamespace=true

Click CREATE and everything should sync! If you used a non-default namespace like nginx and it doesn’t exist yet, then CreateNamespace=true will create it for you.

Things to explore next time

• App settings: sync policies, sync options, etc.
• Refresh: normal vs hard
• Using the HA ArgoCD manifest
• Using proper authentication methods
• Deploying to external clusters
• Diving into more functionality