Creates GitOps tutorial Lesson 2: Promoting from Stage to Production

lessons/02-lesson-2/lesson-manifests/base/combined-pool.yaml

@@ -0,0 +1,25 @@
+apiVersion: kafka.strimzi.io/v1
+kind: KafkaNodePool
+metadata:
+  name: combined
+  labels:
+    strimzi.io/cluster: my-cluster
+spec:
+  replicas: 1
+  roles:
+    - controller
+    - broker
+  storage:
+    type: jbod
+    volumes:
+      - id: 0
+        type: persistent-claim
+        size: 2Gi
+        deleteClaim: true
+  resources:
+    requests:
+      memory: 512Mi
+      cpu: 250m
+    limits:
+      memory: 1Gi
+      cpu: 500m

lessons/02-lesson-2/lesson-manifests/base/kafka.yaml

@@ -0,0 +1,28 @@
+apiVersion: kafka.strimzi.io/v1
+kind: Kafka
+metadata:
+  name: my-cluster
+spec:
+  kafka:
+    version: 4.2.0
+    metadataVersion: "4.2-IV0"
+    listeners:
+      - name: plain
+        port: 9092
+        type: internal
+        tls: false
+    config:
+      offsets.topic.replication.factor: 1
+      transaction.state.log.replication.factor: 1
+      transaction.state.log.min.isr: 1
+      default.replication.factor: 1
+      min.insync.replicas: 1
+  entityOperator:
+    topicOperator:
+      resources:
+        requests:
+          cpu: 100m
+          memory: 256Mi
+        limits:
+          cpu: 250m
+          memory: 384Mi

lessons/02-lesson-2/lesson-manifests/base/kustomization.yaml

@@ -0,0 +1,5 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - combined-pool.yaml
+  - kafka.yaml

lessons/02-lesson-2/lesson-manifests/overlays/production/kustomization.yaml

@@ -0,0 +1,6 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: kafka-production
+resources:
+  - ../../base
+  - namespace.yaml

lessons/02-lesson-2/lesson-manifests/overlays/production/namespace.yaml

@@ -0,0 +1,6 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: kafka-production
+  labels:
+    name: kafka-production

lessons/02-lesson-2/lesson-manifests/overlays/production/topic.yaml

@@ -0,0 +1,12 @@
+apiVersion: kafka.strimzi.io/v1
+kind: KafkaTopic
+metadata:
+  name: my-first-topic
+  labels:
+    strimzi.io/cluster: my-cluster
+spec:
+  partitions: 3
+  replicas: 1
+  config:
+    retention.ms: "86400000"
+    segment.bytes: "1073741824"

lessons/02-lesson-2/lesson-manifests/overlays/staging/kustomization.yaml

@@ -0,0 +1,7 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: kafka-staging
+resources:
+  - ../../base
+  - namespace.yaml
+  - topic.yaml

lessons/02-lesson-2/lesson-manifests/overlays/staging/namespace.yaml

@@ -0,0 +1,6 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: kafka-staging
+  labels:
+    name: kafka-staging

lessons/02-lesson-2/lesson-manifests/overlays/staging/topic.yaml

@@ -0,0 +1,12 @@
+apiVersion: kafka.strimzi.io/v1
+kind: KafkaTopic
+metadata:
+  name: my-first-topic
+  labels:
+    strimzi.io/cluster: my-cluster
+spec:
+  partitions: 3
+  replicas: 1
+  config:
+    retention.ms: "86400000"
+    segment.bytes: "1073741824"

lessons/02-lesson-2/prep.sh

@@ -0,0 +1,225 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+CLUSTER_NAME="gitops-tutorial"
+GITEA_USER="tutorial-user"
+GITEA_PASSWORD="tutorial-password"
+GITEA_REPO="streamshub-gitops"
+GITEA_HOST_PORT=3001
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+info()  { echo -e "\033[1;34m[INFO]\033[0m  $*"; }
+warn()  { echo -e "\033[1;33m[WARN]\033[0m  $*"; }
+error() { echo -e "\033[1;31m[ERROR]\033[0m $*" >&2; }
+b64decode() { echo "$1" | base64 -d 2>/dev/null || echo "$1" | base64 -D 2>/dev/null; }
+
+cleanup() {
+  if [[ -n "${WORK_DIR:-}" ]]; then
+    rm -rf "${WORK_DIR}"
+  fi
+}
+
+# ─── Step 1: Validate infrastructure ──────────────────────────────────────────
+
+info "Validating tutorial infrastructure..."
+
+if ! kind get clusters 2>/dev/null | grep -q "^${CLUSTER_NAME}$"; then
+  error "KinD cluster '${CLUSTER_NAME}' is not running."
+  error "Please run the setup script first: ../00-setup/setup.sh"
+  exit 1
+fi
+
+if ! kubectl get deployment strimzi-cluster-operator -n strimzi-operator &>/dev/null; then
+  error "Strimzi operator not found in namespace 'strimzi-operator'."
+  error "Please run the setup script first: ../00-setup/setup.sh"
+  exit 1
+fi
+
+if ! curl -sf "http://localhost:${GITEA_HOST_PORT}/api/v1/version" >/dev/null 2>&1; then
+  error "Gitea is not reachable on localhost:${GITEA_HOST_PORT}."
+  error "Please run the setup script first: ../00-setup/setup.sh"
+  exit 1
+fi
+
+info "Infrastructure checks passed."
+
+# ─── Step 2: Clean up previous lesson state ───────────────────────────────────
+
+info "Cleaning up previous lesson state..."
+
+# Remove the lesson-1 ArgoCD Application (no cascade finalizer, so this is instant).
+kubectl delete application kafka-tutorial -n argocd --ignore-not-found 2>/dev/null || true
+
+# Also remove any lesson-2 Applications from a previous run of this script.
+kubectl delete application kafka-staging kafka-production -n argocd --ignore-not-found 2>/dev/null || true
+
+# Patch away Strimzi finalizers in all tutorial namespaces so deletions don't hang.
+for ns in kafka-tutorial kafka-staging kafka-production; do
+  for cr_type in kafka kafkanodepool kafkatopic; do
+    kubectl get "${cr_type}" -n "${ns}" -o name 2>/dev/null | \
+      xargs -r -I{} kubectl patch {} -n "${ns}" \
+        --type=merge -p '{"metadata":{"finalizers":null}}' 2>/dev/null || true
+  done
+done
+
+kubectl delete namespace kafka-tutorial kafka-staging kafka-production --ignore-not-found
+
+info "Previous lesson state cleaned up."
+
+# ─── Step 3: Configure Strimzi to watch staging and production namespaces ──────
+
+info "Configuring Strimzi operator for staging and production namespaces..."
+
+for ns in kafka-staging kafka-production; do
+  kubectl create namespace "${ns}" 2>/dev/null || true
+  for rb_name in strimzi-cluster-operator strimzi-cluster-operator-entity-operator-delegation strimzi-cluster-operator-watched; do
+    ROLE_REF=$(kubectl get rolebinding "${rb_name}" -n strimzi-operator -o jsonpath='{.roleRef.name}' 2>/dev/null || echo "")
+    if [[ -n "${ROLE_REF}" ]]; then
+      kubectl create rolebinding "${rb_name}" \
+        --namespace "${ns}" \
+        --clusterrole="${ROLE_REF}" \
+        --serviceaccount=strimzi-operator:strimzi-cluster-operator 2>/dev/null || true
+    fi
+  done
+done
+
+kubectl set env deployment/strimzi-cluster-operator -n strimzi-operator \
+  STRIMZI_NAMESPACE='kafka-staging,kafka-production'
+
+info "Waiting for Strimzi operator to restart..."
+kubectl rollout status deployment/strimzi-cluster-operator -n strimzi-operator --timeout=120s
+
+# ─── Step 4: Seed the Gitea repository with the overlay structure ─────────────
+
+info "Resetting Gitea repository to lesson-2 starting state..."
+
+WORK_DIR=$(mktemp -d)
+trap cleanup EXIT
+
+git clone "http://${GITEA_USER}:${GITEA_PASSWORD}@localhost:${GITEA_HOST_PORT}/${GITEA_USER}/${GITEA_REPO}.git" "${WORK_DIR}/repo" 2>/dev/null
+
+rm -rf "${WORK_DIR}/repo/manifests"
+mkdir -p "${WORK_DIR}/repo/manifests"
+cp -r "${SCRIPT_DIR}/lesson-manifests/." "${WORK_DIR}/repo/manifests/"
+
+pushd "${WORK_DIR}/repo" >/dev/null
+git add .
+if git diff --cached --quiet; then
+  info "Gitea repo is already in lesson-2 starting state, skipping commit."
+else
+  git -c user.name="Tutorial Setup" -c user.email="setup@tutorial.local" commit -m "Reset to lesson-2 starting state"
+  git push
+  info "Lesson-2 starting state pushed to Gitea."
+fi
+TARGET_REVISION=$(git rev-parse HEAD)
+popd >/dev/null
+
+# ─── Step 5: Create ArgoCD Applications for staging and production ─────────────
+
+info "Creating ArgoCD applications for staging and production..."
+
+kubectl apply -f - <<EOF
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: kafka-staging
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: http://gitea-http.gitea.svc:3000/tutorial-user/streamshub-gitops.git
+    targetRevision: main
+    path: manifests/overlays/staging
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: kafka-staging
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    managedNamespaceMetadata:
+      labels:
+        argocd.argoproj.io/managed-by: argocd
+    syncOptions:
+      - CreateNamespace=true
+EOF
+
+kubectl apply -f - <<EOF
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: kafka-production
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: http://gitea-http.gitea.svc:3000/tutorial-user/streamshub-gitops.git
+    targetRevision: main
+    path: manifests/overlays/production
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: kafka-production
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    managedNamespaceMetadata:
+      labels:
+        argocd.argoproj.io/managed-by: argocd
+    syncOptions:
+      - CreateNamespace=true
+EOF
+
+# ─── Step 6: Wait for both applications to sync ───────────────────────────────
+
+info "Waiting for ArgoCD to sync both applications..."
+
+kubectl annotate application kafka-staging -n argocd argocd.argoproj.io/refresh=normal --overwrite >/dev/null 2>&1 || true
+kubectl annotate application kafka-production -n argocd argocd.argoproj.io/refresh=normal --overwrite >/dev/null 2>&1 || true
+
+for app in kafka-staging kafka-production; do
+  SYNC_STATUS="Unknown"
+  for i in $(seq 1 24); do
+    CURRENT_REVISION=$(kubectl get application "${app}" -n argocd -o jsonpath='{.status.sync.revision}' 2>/dev/null || echo "")
+    SYNC_STATUS=$(kubectl get application "${app}" -n argocd -o jsonpath='{.status.sync.status}' 2>/dev/null || echo "Unknown")
+    if [[ "${CURRENT_REVISION}" == "${TARGET_REVISION}" && "${SYNC_STATUS}" == "Synced" ]]; then
+      break
+    fi
+    sleep 5
+  done
+
+  if [[ "${SYNC_STATUS}" != "Synced" ]]; then
+    warn "Application '${app}' has not synced yet (status: ${SYNC_STATUS})."
+    warn "Check with: kubectl get application ${app} -n argocd"
+  else
+    info "Application '${app}' is synced."
+  fi
+done
+
+info "Waiting for Kafka clusters to be ready (this may take a few minutes)..."
+kubectl wait kafka/my-cluster --for=condition=Ready -n kafka-staging --timeout=600s 2>/dev/null &
+kubectl wait kafka/my-cluster --for=condition=Ready -n kafka-production --timeout=600s 2>/dev/null &
+wait
+
+# ─── Step 7: Print starting instructions ──────────────────────────────────────
+
+ARGOCD_PASSWORD=$(b64decode "$(kubectl get secret argocd-initial-admin-secret -n argocd -o jsonpath='{.data.password}')")
+
+echo ""
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+echo ""
+info "Lesson 2 is ready. Open README.md and follow the lesson steps."
+echo ""
+echo "  Clone the repo to follow along:"
+echo "     git clone http://${GITEA_USER}:${GITEA_PASSWORD}@localhost:${GITEA_HOST_PORT}/${GITEA_USER}/${GITEA_REPO}.git /tmp/gitops-lesson-2"
+echo ""
+echo "  Gitea (your Git server):  http://localhost:${GITEA_HOST_PORT}"
+echo "  Username: ${GITEA_USER}   Password: ${GITEA_PASSWORD}"
+echo ""
+echo "  ArgoCD Dashboard (open in a separate terminal):"
+echo "     kubectl port-forward svc/argocd-server -n argocd 8080:443"
+echo "     URL:      https://localhost:8080"
+echo "     Username: admin"
+echo "     Password: ${ARGOCD_PASSWORD}"
+echo ""
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

lessons/README.md

@@ -16,6 +16,7 @@ A shared cluster runs for the whole series. You set it up once, then run a short
 |---|-------|-----------------|
 | [Getting Started](00-setup/README.md) | Environment setup | Install the shared cluster, ArgoCD, Strimzi, and a local Git server. Run this once before any lesson. |
 | [Lesson 1](01-lesson-1/README.md) | Your First GitOps Change | Add a Kafka topic by editing a file in Git and watch ArgoCD deploy it automatically — without running `kubectl apply`. |
+| [Lesson 2](02-lesson-2/README.md) | Promoting Changes Across Environments | Use kustomize overlays to manage staging and production separately, then promote a topic from staging to production with a single Git change. |
 
 ---