docs(e2e): add GMP sidecar injection example script and test

e2e/examples_test.go

@@ -0,0 +1,124 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//	https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package e2e
+
+import (
+	"context"
+	"os/exec"
+	"testing"
+	"time"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+func TestInjectGMPSidecarExample(t *testing.T) {
+	ctx := contextWithDeadline(t)
+
+	kubeClient, _, err := setupCluster(ctx, t)
+	if err != nil {
+		t.Fatalf("error setting up cluster: %s", err)
+	}
+
+	// 1. Create example-deployment in default namespace.
+	deployment := &appsv1.Deployment{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "example-deployment",
+			Namespace: "default",
+		},
+		Spec: appsv1.DeploymentSpec{
+			Selector: &metav1.LabelSelector{
+				MatchLabels: map[string]string{
+					"app": "example-service",
+				},
+			},
+			Template: corev1.PodTemplateSpec{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						"app": "example-service",
+					},
+				},
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{
+						{
+							Name:  "example-service",
+							Image: "nginx:latest", // Just a dummy image.
+						},
+					},
+				},
+			},
+		},
+	}
+
+	if err := kubeClient.Create(ctx, deployment); err != nil {
+		t.Fatalf("error creating example-deployment: %s", err)
+	}
+	defer func() {
+		_ = kubeClient.Delete(ctx, deployment)
+		_ = kubeClient.Delete(ctx, &corev1.ConfigMap{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "example-deployment",
+				Namespace: deployment.Namespace,
+			},
+		})
+	}()
+
+	// 2. Run the bash script.
+	cmd := exec.CommandContext(ctx, "../examples/inject-gmp-sidecar.sh")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("error running inject-gmp-sidecar.sh: %s\n%s", err, string(out))
+	}
+	t.Logf("script output: %s", string(out))
+
+	// 3. Verify sidecars are injected and ConfigMap is created.
+	if err := wait.PollUntilContextCancel(ctx, 2*time.Second, true, func(ctx context.Context) (bool, error) {
+		cm := &corev1.ConfigMap{}
+		if getErr := kubeClient.Get(ctx, client.ObjectKey{Name: "example-deployment", Namespace: "default"}, cm); getErr != nil {
+			return false, nil //nolint:nilerr
+		}
+		if cm.Data["config.yaml"] == "" {
+			return false, nil //nolint:nilerr
+		}
+
+		dep := &appsv1.Deployment{}
+		if getErr := kubeClient.Get(ctx, client.ObjectKey{Name: "example-deployment", Namespace: "default"}, dep); getErr != nil {
+			return false, nil //nolint:nilerr
+		}
+
+		containers := dep.Spec.Template.Spec.Containers
+		if len(containers) != 3 {
+			return false, nil //nolint:nilerr
+		}
+
+		hasProm := false
+		hasReloader := false
+		for _, c := range containers {
+			if c.Name == "prometheus" {
+				hasProm = true
+			}
+			if c.Name == "config-reloader" {
+				hasReloader = true
+			}
+		}
+
+		return hasProm && hasReloader, nil
+	}); err != nil {
+		t.Fatalf("failed to verify injected sidecars or config map: %s", err)
+	}
+}

examples/inject-gmp-sidecar.sh

@@ -0,0 +1,140 @@
+#!/usr/bin/env bash
+# Copyright 2024 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -exuo pipefail
+
+KIND="deployment"
+NAMESPACE="default"
+NAME="example-deployment"
+CONTAINER="example-service"
+METRICS_PATH="/metrics"
+PORT=80
+
+if ! command -v yq &> /dev/null; then
+  echo "Error: yq is not installed. Please install it (e.g., via 'go install github.com/mikefarah/yq/v4@latest' or from https://github.com/mikefarah/yq)." >&2
+  exit 1
+fi
+
+# Extract labels.
+CLUSTER_NAME=$(kubectl -n gmp-system get configmap/collector -o jsonpath='{.data.config\.yaml}' | yq '.global.external_labels.cluster')
+LOCATION=$(kubectl -n gmp-system get configmap/collector -o jsonpath='{.data.config\.yaml}' | yq '.global.external_labels.location')
+PROJECT_ID=$(kubectl -n gmp-system get configmap/collector -o jsonpath='{.data.config\.yaml}' | yq '.global.external_labels.project_id')
+
+
+if [[ -z "${CLUSTER_NAME}" || -z "${LOCATION}" || -z "${PROJECT_ID}" ]]; then
+  echo "Error: Failed to extract cluster, location, or project_id from gmp-system/collector configmap." >&2
+  exit 1
+fi
+
+# Images need to be updated periodically.
+DISTROLESS_IMAGE=gke.gcr.io/gke-distroless/bash:gke_distroless_20240220.00_p0@sha256:828371616edc2c38e36868e2f8c992df37e484df72670f148de59867dfdd2490
+PROMETHEUS_IMAGE=gke.gcr.io/prometheus-engine/prometheus:v2.53.5-gmp.4-gke.0@sha256:6f349dc0be36c8a61be183254f1126c9935f5332daa96c481f7e0e1b20fe0513
+CONFIG_RELOADER_IMAGE=gke.gcr.io/prometheus-engine/config-reloader:v0.18.0-gke.2@sha256:b41862ee7ee3e9f24112ccdb0e53060085af1a8347054a7dbcff04467d3e1e9c
+
+# Define the scrape configuration.
+CONFIG_MAP=$(
+	cat <<INNER_EOF
+global:
+  scrape_interval: 30s
+  external_labels:
+    cluster: ${CLUSTER_NAME}
+    location: ${LOCATION}
+    project_id: ${PROJECT_ID}
+scrape_configs:
+- job_name: DedicatedCollector/${NAME}
+  metrics_path: ${METRICS_PATH}
+  static_configs:
+  - targets: ['localhost:${PORT}']
+    labels:
+      # Common GMP labels.
+      container: ${CONTAINER}
+      node: \$(NODE_NAME)
+      pod: \$(POD_NAME)
+      top_level_controller_name: ${NAME}
+      top_level_controller_type: ${KIND}
+INNER_EOF
+)
+
+
+
+kubectl -n "${NAMESPACE}" create configmap "${NAME}" --from-literal="config.yaml=${CONFIG_MAP}" --dry-run=client -o yaml | kubectl apply -f -
+
+# Construct Strategic Merge Patch.
+STRATEGIC_PATCH=$(
+	cat <<INNER_EOF
+spec:
+  template:
+    spec:
+      volumes:
+      - name: config
+        configMap:
+          name: ${NAME}
+      - name: prometheus-db
+        emptyDir: {}
+      - name: config-out
+        emptyDir: {}
+      initContainers:
+      - name: config-init
+        image: ${DISTROLESS_IMAGE}
+        command: ["/bin/bash", "-c", ": > /prometheus/config_out/config.yaml"]
+        volumeMounts:
+        - name: config-out
+          mountPath: /prometheus/config_out
+      containers:
+      - name: prometheus
+        image: ${PROMETHEUS_IMAGE}
+        args:
+        - --config.file=/prometheus/config_out/config.yaml
+        - --storage.tsdb.path=/prometheus/data
+        - --storage.tsdb.retention.time=24h
+        - --web.enable-lifecycle
+        - --storage.tsdb.no-lockfile
+        - --web.route-prefix=/
+        - --log.level=debug
+        ports:
+        - containerPort: 9090
+        volumeMounts:
+        - name: config-out
+          mountPath: /prometheus/config_out
+          readOnly: true
+        - name: prometheus-db
+          mountPath: /prometheus/data
+      - name: config-reloader
+        image: ${CONFIG_RELOADER_IMAGE}
+        args:
+        - --config-file=/prometheus/config/config.yaml
+        - --config-file-output=/prometheus/config_out/config.yaml
+        - --reload-url=http://localhost:9090/-/reload
+        - --ready-url=http://localhost:9090/-/ready
+        - --listen-address=:19091
+        env:
+        - name: NODE_NAME
+          valueFrom:
+            fieldRef:
+              fieldPath: spec.nodeName
+        - name: POD_NAME
+          valueFrom:
+            fieldRef:
+              fieldPath: metadata.name
+        volumeMounts:
+        - name: config
+          mountPath: /prometheus/config
+        - name: config-out
+          mountPath: /prometheus/config_out
+INNER_EOF
+)
+
+# Apply the Patch
+kubectl -n "${NAMESPACE}" patch "${KIND}" "${NAME}" --patch "${STRATEGIC_PATCH}"

hack/Dockerfile

@@ -88,6 +88,9 @@ RUN ARCH=$(dpkg --print-architecture) && \
 	curl -Lo ./jq "https://github.com/jqlang/jq/releases/download/jq-1.7/jq-linux-${ARCH}" && \
 	install -o root -g root -m 0755 jq /usr/local/bin/jq && \
 	rm jq && \
+		curl -Lo ./yq "https://github.com/mikefarah/yq/releases/download/v4.44.3/yq_linux_${ARCH}" && \
+		install -o root -g root -m 0755 yq /usr/local/bin/yq && \
+		rm yq && \
 	curl -Lo ./kind "https://kind.sigs.k8s.io/dl/v0.26.0/kind-linux-${ARCH}" && \
 	install -o root -g root -m 0755 kind /usr/local/bin/kind && \
 	rm kind