GitOps Cheat Sheet

GitOps Principles


         Git as single source of truth

All configuration stored in Git repositories


         Declarative infrastructure

Define desired state, not imperative steps


         Automated synchronization

Automatic deployment from Git to clusters


         Continuous reconciliation

System constantly moves toward desired state


         Pull-based deployment

Cluster pulls changes from Git (not pushed)


         Immutable infrastructure

Changes via Git commits, not manual edits


         Version control everything

Infrastructure, apps, configs all in Git


         Audit trail through Git history

Full history of changes and rollback capability

ArgoCD Installation


         kubectl create namespace argocd

Create ArgoCD namespace


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

Install ArgoCD in cluster


         kubectl get pods -n argocd

Verify ArgoCD pods are running


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

Access ArgoCD UI locally


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

Get initial admin password


         argocd login localhost:8080

Login via ArgoCD CLI


         argocd account update-password

Change admin password

ArgoCD Applications


         argocd app create myapp --repo https://github.com/user/repo --path manifests --dest-server https://kubernetes.default.svc --dest-namespace default

Create ArgoCD application via CLI


         argocd app list

List all applications


         argocd app get myapp

Get application details


         argocd app sync myapp

Manually sync application


         argocd app set myapp --sync-policy automated

Enable auto-sync for application


         argocd app set myapp --auto-prune

Enable automatic pruning of resources


         argocd app set myapp --self-heal

Enable self-healing for drift correction


         argocd app delete myapp

Delete application from ArgoCD


         argocd app rollback myapp

Rollback to previous version


         argocd app history myapp

View deployment history


         argocd app diff myapp

Show diff between Git and cluster


         argocd app wait myapp

Wait for application to reach synced state

ArgoCD Application YAML


         apiVersion: argoproj.io/v1alpha1

ArgoCD Application API version


         kind: Application

Resource kind for Application


         spec.source.repoURL: https://github.com/user/repo

Git repository URL


         spec.source.targetRevision: HEAD

Branch, tag, or commit to track


         spec.source.path: ./k8s

Path to manifests in repo


         spec.destination.server: https://kubernetes.default.svc

Target Kubernetes cluster


         spec.destination.namespace: production

Target namespace


         spec.syncPolicy.automated.prune: true

Enable automatic pruning


         spec.syncPolicy.automated.selfHeal: true

Enable automatic self-healing


         spec.syncPolicy.syncOptions: ["CreateNamespace=true"]

Sync options like auto-create namespace

ArgoCD with Helm


         spec.source.helm.releaseName: myrelease

Specify Helm release name


         spec.source.helm.valueFiles: [values-prod.yaml]

Specify Helm values files


         spec.source.helm.values: |

Inline Helm values in Application


         spec.source.helm.parameters: [{name: image.tag, value: v1.0}]

Override specific Helm values


         spec.source.chart: mychart

Helm chart name (for chart repos)


         spec.source.repoURL: https://charts.example.com

Helm chart repository URL


         spec.source.targetRevision: 1.2.3

Helm chart version

ArgoCD with Kustomize


         spec.source.kustomize.namePrefix: prod-

Add prefix to resource names


         spec.source.kustomize.nameSuffix: -v2

Add suffix to resource names


         spec.source.kustomize.images: [nginx=nginx:1.21]

Override container images


         spec.source.kustomize.commonLabels: {env: prod}

Add labels to all resources


         spec.source.kustomize.commonAnnotations: {owner: team-a}

Add annotations to all resources


         argocd app set myapp --kustomize-image nginx=nginx:1.22

Override image via CLI

FluxCD Installation


         curl -s https://fluxcd.io/install.sh | sudo bash

Install Flux CLI


         flux check --pre

Check cluster prerequisites


         export GITHUB_TOKEN=<token>

Set GitHub personal access token


         flux bootstrap github --owner=user --repository=fleet --path=clusters/prod --personal

Bootstrap Flux to GitHub repository


         flux check

Verify Flux installation


         kubectl get pods -n flux-system

Check Flux components

FluxCD GitRepository


         flux create source git myapp --url=https://github.com/user/repo --branch=main

Create Git source


         flux get sources git

List Git sources


         apiVersion: source.toolkit.fluxcd.io/v1

GitRepository API version


         kind: GitRepository

Resource kind for Git source


         spec.url: https://github.com/user/repo

Repository URL


         spec.ref.branch: main

Track specific branch


         spec.interval: 1m

Sync interval for repository


         spec.secretRef.name: git-credentials

Reference to authentication secret

FluxCD Kustomization


         flux create kustomization myapp --source=myapp --path="./kustomize" --prune=true

Create Kustomization resource


         flux get kustomizations

List all Kustomizations


         apiVersion: kustomize.toolkit.fluxcd.io/v1

Kustomization API version


         kind: Kustomization

Resource kind for Flux Kustomization


         spec.sourceRef.kind: GitRepository

Reference to Git source


         spec.path: ./deploy/production

Path to manifests in repository


         spec.prune: true

Enable pruning of deleted resources


         spec.interval: 10m

Reconciliation interval


         spec.targetNamespace: production

Override namespace for resources


         spec.healthChecks: [{kind: Deployment, name: app}]

Define health check resources


         spec.wait: true

Wait for resources to be ready


         spec.timeout: 5m

Timeout for reconciliation

FluxCD HelmRelease


         flux create helmrelease myapp --source=HelmRepository/myrepo --chart=mychart --target-namespace=default

Create Helm release


         apiVersion: helm.toolkit.fluxcd.io/v2

HelmRelease API version


         spec.chart.spec.chart: nginx

Helm chart name


         spec.chart.spec.version: "1.2.x"

Chart version (supports semver)


         spec.values: {replicaCount: 3}

Inline Helm values


         spec.valuesFrom: [{kind: ConfigMap, name: values}]

Load values from ConfigMap/Secret


         spec.install.remediation.retries: 3

Retry failed installations


         spec.upgrade.remediation.strategy: rollback

Rollback on failed upgrade

Secrets Management


         kubectl create secret generic git-credentials --from-literal=username=user --from-literal=password=token

Create Git credentials secret


         flux create secret git flux-system --url=https://github.com/user/repo --username=user --password=token

Create Flux Git secret via CLI


         Mozilla SOPS integration

Encrypt secrets in Git with SOPS


         Sealed Secrets with ArgoCD/Flux

Encrypt secrets for safe Git storage


         External Secrets Operator

Sync secrets from external vaults


         spec.decryption.provider: sops

Enable SOPS decryption in Flux


         sops --encrypt --in-place secret.yaml

Encrypt secret file with SOPS


         age-keygen -o age.key

Generate age key for SOPS

Multi-Cluster Management


         argocd cluster add context-name

Add cluster to ArgoCD


         argocd cluster list

List registered clusters


         spec.destination.name: production-cluster

Target named cluster in Application


         ApplicationSet for multiple clusters

Deploy to multiple clusters with templates


         flux bootstrap for each cluster

Bootstrap Flux on each cluster separately


         Cluster-specific paths: clusters/prod, clusters/dev

Organize manifests by cluster