ArgoCD GitOps

Implement declarative continuous delivery for Kubernetes with ArgoCD.

When to Use This Skill

Use this skill when:

• Implementing GitOps workflows for Kubernetes
• Automating deployments from Git repositories
• Managing multiple environments declaratively
• Implementing progressive delivery strategies
• Synchronizing cluster state with Git

Prerequisites

• Kubernetes cluster with ArgoCD installed
• kubectl configured
• Git repository for manifests
• ArgoCD CLI (optional)

Installation

# Create namespace
kubectl create namespace argocd

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

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

# Port forward to access UI
kubectl port-forward svc/argocd-server -n argocd 8080:443

# Login with CLI
argocd login localhost:8080

Application Definition

Basic Application

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/myapp-manifests.git
    targetRevision: main
    path: environments/production
  destination:
    server: https://kubernetes.default.svc
    namespace: myapp
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
      - CreateNamespace=true

Helm Application

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp-helm
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/myapp-chart.git
    targetRevision: main
    path: charts/myapp
    helm:
      valueFiles:
        - values.yaml
        - values-production.yaml
      parameters:
        - name: replicaCount
          value: "3"
        - name: image.tag
          value: "2.0.0"
  destination:
    server: https://kubernetes.default.svc
    namespace: myapp
  syncPolicy:
    automated:
      prune: true
      selfHeal: true

Kustomize Application

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: myapp-kustomize
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/org/myapp-manifests.git
    targetRevision: main
    path: overlays/production
    kustomize:
      images:
        - myapp=myregistry/myapp:2.0.0
  destination:
    server: https://kubernetes.default.svc
    namespace: myapp

Projects

apiVersion: argoproj.io/v1alpha1
kind: AppProject
metadata:
  name: myproject
  namespace: argocd
spec:
  description: My Project
  sourceRepos:
    - https://github.com/org/*
  destinations:
    - namespace: myapp-*
      server: https://kubernetes.default.svc
  clusterResourceWhitelist:
    - group: ''
      kind: Namespace
  namespaceResourceWhitelist:
    - group: '*'
      kind: '*'
  roles:
    - name: developer
      description: Developer role
      policies:
        - p, proj:myproject:developer, applications, get, myproject/*, allow
        - p, proj:myproject:developer, applications, sync, myproject/*, allow
      groups:
        - developers

Application Sets

Git Generator

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: myapp-environments
  namespace: argocd
spec:
  generators:
    - git:
        repoURL: https://github.com/org/myapp-manifests.git
        revision: main
        directories:
          - path: environments/*
  template:
    metadata:
      name: 'myapp-{{path.basename}}'
    spec:
      project: default
      source:
        repoURL: https://github.com/org/myapp-manifests.git
        targetRevision: main
        path: '{{path}}'
      destination:
        server: https://kubernetes.default.svc
        namespace: 'myapp-{{path.basename}}'
      syncPolicy:
        automated:
          prune: true
          selfHeal: true

List Generator

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: myapp-clusters
  namespace: argocd
spec:
  generators:
    - list:
        elements:
          - cluster: production
            url: https://prod-cluster.example.com
          - cluster: staging
            url: https://staging-cluster.example.com
  template:
    metadata:
      name: 'myapp-{{cluster}}'
    spec:
      project: default
      source:
        repoURL: https://github.com/org/myapp-manifests.git
        targetRevision: main
        path: 'environments/{{cluster}}'
      destination:
        server: '{{url}}'
        namespace: myapp

Matrix Generator

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: myapp-matrix
  namespace: argocd
spec:
  generators:
    - matrix:
        generators:
          - git:
              repoURL: https://github.com/org/myapp-manifests.git
              revision: main
              directories:
                - path: apps/*
          - lis