Deploying apps with ArgoCD

Live demo code snippets for my talk on MakeIT/JCon 2023.

Repository structure

• manual-apply contains yaml files that have to be applied manually
• repository-ops is a folder that simulates another repository, a repository meant to kick-start app deployment
  • for this particular demo, the repository contains the kick-start part, but also Application deployments of 2 teams - in real life, this could be moved to other repositories(depends on the side of the organisation)
• repository-team-blue/repository-team-red are also folders that simulate repositories, these repositories contain manifests that describe which objects should be deployed for which Application that belongs to the associated team
• (bonus folder) sample-yamls contains various yaml files that I needed to prepare the presentation

Each "repository simulation" folder has its own README.md describing its purpose in more details.

Local setup

Kubernetes cluster

While you can use a manged service such as AWS EKS or DigitalOcean Managed Kubernetes, I usually do such tests locally on my laptop. Most of the time I use k3d:

k3d cluster create makeit-argocd -p "8081:80@loadbalancer"

This command will create a k3d cluster, add its config to your local kube config and expose it's load-balancer on your local 8080 port.

ArgoCD

This step is pretty straight forward:

# be sure your local context is the desired one!
kubectl create namespace argocd
kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

ArgoCD - admin user credentials

Whenever you do a fresh ArgoCD install, you get a fresh admin password stored in a secret. The easiest way to retrieve it is with:

kubectl -n argocd get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d; echo

ArgoCD - WebUI access

Since we won't be configuring a Kubernetes Ingress within the demo, we have to port foward directly to the ArgoCD Service:

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

Now the UI should be available at: http://localhost:8080/applications. Note: you might get a warning from the browser that the connection is not secure, that's normal at this point with such setup.

Cluster demo apps boostrap

This step will initialise the cluster with all configured apps/projects/namespaces/... :

kubectl apply -f manual-apply/bootstrap.yaml

This is considered as a "push" change.