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Setting up ArgoCD - GitOps Continuous Deployment Tool

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Overview

Learn about ArgoCD, a declarative GitOps continuous deployment tool for Kubernetes.


What is ArgoCD?

ArgoCD is a declarative GitOps CD tool for Kubernetes that:

🔍 Why ArgoCD?

What is GitOps?

GitOps is a term first used by Weaveworks Inc. in 2017 and is one of DevOps’ practices in projects.

It focuses on continuous deployment targeting cloud-native applications.

As the word indicates, it means that all elements related to the distribution and operation of the application are coded and managed in Git.

HTTPS

ArgoCD Components Architecture

ArgoCD Components Architecture


Installation

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

# Install Argocd Helm Chart https://argo-cd.readthedocs.io/en/latest/user-guide/helm/
# Reference: https://github.com/somaz94/helm-chart-template/tree/main/k8s-service/argocd/argo-cd
helm install argocd argo-cd --namespace argocd --create-namespace --version <version>

# Install ArgoCD CLI
curl -sL -o argocd https://github.com/argoproj/argo-cd/releases/download/v2.7.1/argocd-linux-amd64
chmod +x argocd
sudo mv argocd /usr/local/bin/


Helm Values Example

# values.yaml for Helm installation
server:
  extraArgs:
    - --insecure
  ingress:
    enabled: true
    hosts:
      - argocd.example.com
    annotations:
      kubernetes.io/ingress.class: nginx
      nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
      nginx.ingress.kubernetes.io/ssl-passthrough: "true"
      nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
  resources:
    limits:
      cpu: 500m
      memory: 512Mi
    requests:
      cpu: 200m
      memory: 256Mi
  
repoServer:
  resources:
    limits:
      cpu: 300m
      memory: 512Mi
    requests:
      cpu: 100m
      memory: 256Mi

applicationSet:
  enabled: true

notifications:
  enabled: true

dex:
  enabled: false

To install with custom values:

helm install argocd argo-cd -f values.yaml --namespace argocd --create-namespace


Ingress Configuration



Initial Setup

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

# Verify installation
kubectl get po,svc,ingress,sts -n argocd

Login

HTTPS


Managing Applications

Application Definition

Create an application in ArgoCD:

# application.yaml
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: guestbook
  namespace: argocd
spec:
  project: default
  source:
    repoURL: https://github.com/argoproj/argocd-example-apps.git
    targetRevision: HEAD
    path: guestbook
  destination:
    server: https://kubernetes.default.svc
    namespace: guestbook
  syncPolicy:
    automated:
      prune: true
      selfHeal: true
    syncOptions:
    - CreateNamespace=true

Apply the application:

kubectl apply -f application.yaml

CLI Management

# Log in to ArgoCD
argocd login argocd.somaz.link

# List applications
argocd app list

# Get application details
argocd app get guestbook

# Manually sync an application
argocd app sync guestbook

# Create an application via CLI
argocd app create guestbook --repo https://github.com/argoproj/argocd-example-apps.git --path guestbook --dest-server https://kubernetes.default.svc --dest-namespace guestbook


Advanced Configuration

SSO Integration

You can integrate ArgoCD with Identity Providers using OIDC:

apiVersion: v1
kind: ConfigMap
metadata:
  name: argocd-cm
  namespace: argocd
data:
  url: https://argocd.somaz.link
  
  # OIDC Configuration
  oidc.config: |
    name: Okta
    issuer: https://dev-123456.okta.com
    clientID: 0oabcdefghijklmn
    clientSecret: '$oidc.okta.clientSecret'
    requestedScopes: ["openid", "profile", "email", "groups"]
    requestedIDTokenClaims:
      groups:
        essential: true

Create a secret for the client secret:

kubectl create secret generic argocd-secret --from-literal=oidc.okta.clientSecret=your-client-secret -n argocd

RBAC Configuration

Configure RBAC in ArgoCD:

apiVersion: v1
kind: ConfigMap
metadata:
  name: argocd-rbac-cm
  namespace: argocd
data:
  policy.csv: |
    # Project roles
    p, role:dev-readonly, applications, get, dev/*, allow
    p, role:dev-admin, applications, *, dev/*, allow
    
    # Group mappings
    g, dev-team, role:dev-readonly
    g, devops-team, role:dev-admin
    
    # Allow admins to do everything
    p, role:org-admin, applications, *, */*, allow
    g, admin-team, role:org-admin


ApplicationSet Example

ApplicationSets help manage multiple similar applications:

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: microservices
  namespace: argocd
spec:
  generators:
  - list:
      elements:
      - name: api
        namespace: microservices
        path: services/api
      - name: auth
        namespace: microservices
        path: services/auth
      - name: frontend
        namespace: microservices
        path: services/frontend
  template:
    metadata:
      name: ''
    spec:
      project: default
      source:
        repoURL: https://github.com/myorg/microservices.git
        targetRevision: HEAD
        path: ''
      destination:
        server: https://kubernetes.default.svc
        namespace: ''
      syncPolicy:
        automated:
          prune: true
          selfHeal: true


Monitoring and Troubleshooting

Health Status Dashboard

ArgoCD provides a dashboard to monitor the health of your applications. If you encounter issues, check these common problems:


Common Issues and Solutions:

1. Application Out of Sync: - Check Git repository connectivity
- Verify branch/tag/commit reference
- Inspect detailed sync status: argocd app get [app-name]

2. Authentication Failures: - Ensure Git credentials are correct
- Check SSH keys or access tokens
- Verify network connectivity to Git provider

3. Resource Creation Failures: - Check RBAC permissions
- Verify namespace exists (or enable auto-creation)
- Look for validation errors: kubectl logs deployment/argocd-repo-server -n argocd

4. Webhook Integration Issues: - Ensure webhook is properly configured
- Check network connectivity from Git provider to ArgoCD
- Verify payload structure and secrets

Useful Diagnostic Commands

# Check ArgoCD server logs
kubectl logs -n argocd -l app.kubernetes.io/name=argocd-server

# Check repo server logs (for Git issues)
kubectl logs -n argocd -l app.kubernetes.io/name=argocd-repo-server

# Check controller logs (for sync issues)
kubectl logs -n argocd -l app.kubernetes.io/name=argocd-application-controller

# Get detailed application status
argocd app get myapp --hard-refresh

# Check recent application events
kubectl get events -n argocd --sort-by='.lastTimestamp'


Backup and Restore

Backup ArgoCD

# Backup ArgoCD application definitions
kubectl get applications -n argocd -o yaml > argocd-applications-backup.yaml

# Backup ArgoCD projects
kubectl get appprojects -n argocd -o yaml > argocd-projects-backup.yaml

# Backup ArgoCD settings and configurations
kubectl get configmap argocd-cm -n argocd -o yaml > argocd-cm-backup.yaml
kubectl get configmap argocd-rbac-cm -n argocd -o yaml > argocd-rbac-cm-backup.yaml
kubectl get secret argocd-secret -n argocd -o yaml > argocd-secret-backup.yaml

Restore ArgoCD

# Restore from backups
kubectl apply -f argocd-applications-backup.yaml
kubectl apply -f argocd-projects-backup.yaml
kubectl apply -f argocd-cm-backup.yaml
kubectl apply -f argocd-rbac-cm-backup.yaml
kubectl apply -f argocd-secret-backup.yaml


Best Practices


1. Security: - Change default admin password
- Use SSL/TLS
- Implement RBAC
- Regularly rotate secrets and credentials
- Use private Git repositories

2. High Availability: - Use HA installation for production
- Configure proper backup
- Monitor resources
- Set appropriate resource limits
- Use node affinity for critical components

3. GitOps Workflow: - Use declarative configurations
- Version control everything
- Automate deployments
- Implement PR approval workflows
- Organize repositories by environment

4. Performance: - Use ApplicationSets for managing multiple applications
- Configure reasonable sync periods
- Utilize webhooks for immediate updates
- Implement proper caching strategies
- Monitor and adjust resource limits as needed


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