✨ Add Prometheus instance support to sample external plugin: implement init and edit commands, update manifests, and enhance test scripts

Author: nerdeveloper

docs/book/src/plugins/extending/external-plugins.md

@@ -30,6 +30,17 @@ structures.
 
 `PluginRequest` contains the data collected from the CLI and any previously executed plugins. Kubebuilder sends this data as a JSON object to the external plugin via `stdin`.
 
+**Example `PluginRequest` (triggered by `kubebuilder init --plugins sampleexternalplugin/v1`):**
+
+```json
+{
+  "apiVersion": "v1alpha1",
+  "args": [],
+  "command": "init",
+  "universe": {}
+}
+```
+
 **Example `PluginRequest` (triggered by `kubebuilder edit --plugins sampleexternalplugin/v1`):**
 
 ```json
@@ -51,12 +62,12 @@ structures.
   "apiVersion": "v1alpha1",
   "command": "edit",
   "metadata": {
-    "description": "The `edit` subcommand adds Prometheus ServiceMonitor configuration for monitoring your operator.",
+    "description": "The `edit` subcommand adds Prometheus instance configuration for monitoring your operator.",
     "examples": "kubebuilder edit --plugins sampleexternalplugin/v1"
   },
   "universe": {
-    "config/prometheus/monitor.yaml": "# Prometheus ServiceMonitor manifest...",
-    "config/prometheus/kustomization.yaml": "resources:\n  - monitor.yaml\n"
+    "config/prometheus/prometheus.yaml": "# Prometheus instance manifest...",
+    "config/prometheus/kustomization.yaml": "resources:\n  - prometheus.yaml\n"
   },
   "error": false,
   "errorMsgs": []
@@ -121,10 +132,15 @@ Otherwise, Kubebuilder would search for the plugins in a default path based on y
 You can now use it by calling the CLI commands:
 
 ```sh
-# Update the project configuration with the sample external plugin
-# The sampleexternalplugin adds Prometheus ServiceMonitor configuration
+# Initialize a new project with Prometheus monitoring
+kubebuilder init --plugins sampleexternalplugin/v1
+
+# Update an existing project with Prometheus monitoring
 kubebuilder edit --plugins sampleexternalplugin/v1
 
+# Display help information for the init subcommand
+kubebuilder init --plugins sampleexternalplugin/v1 --help
+
 # Display help information for the edit subcommand
 kubebuilder edit --plugins sampleexternalplugin/v1 --help
 

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/.gitignore

@@ -0,0 +1,20 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+sampleexternalplugin
+bin/
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Go workspace file
+go.work
+
+# Temporary test directories
+testdata/testplugin/

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/Makefile

@@ -63,3 +63,7 @@ install: build ## Build and install the binary with the current source code. Use
 .PHONY: test-plugin
 test-plugin: ## Run the plugin test.
 	./test/test.sh
+
+.PHONY: clean
+clean: ## Clean build artifacts.
+	rm -rf ./bin

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/cmd/cmd.go

@@ -59,6 +59,9 @@ func Run() {
 
 	// Run logic depending on the command that is requested by Kubebuilder
 	switch pluginRequest.Command {
+	// the `init` subcommand is used to add features during project initialization
+	case "init":
+		response = scaffolds.InitCmd(pluginRequest)
 	// the `edit` subcommand is used to add optional features to an existing project
 	// This is a realistic use case for external plugins - adding optional monitoring
 	case "edit":

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/cmd/flags.go

@@ -36,13 +36,27 @@ func flagsCmd(pr *external.PluginRequest) external.PluginResponse {
 		Flags:      []external.Flag{},
 	}
 
-	switch pr.Command {
+	// Parse args to determine which subcommand flags are being requested
+	var subcommand string
+	for _, arg := range pr.Args {
+		if arg == "--init" {
+			subcommand = "init"
+			break
+		} else if arg == "--edit" {
+			subcommand = "edit"
+			break
+		}
+	}
+
+	switch subcommand {
+	case "init":
+		pluginResponse.Flags = scaffolds.InitFlags
 	case "edit":
 		pluginResponse.Flags = scaffolds.EditFlags
 	default:
 		pluginResponse.Error = true
 		pluginResponse.ErrorMsgs = []string{
-			"unrecognized command: " + pr.Command,
+			"unrecognized subcommand flag in args: " + string(rune(len(pr.Args))),
 		}
 	}
 

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/cmd/metadata.go

@@ -39,6 +39,7 @@ func metadataCmd(pr *external.PluginRequest) external.PluginResponse {
 
 	// Here is an example of parsing multiple flags from a Kubebuilder external plugin request
 	flagsToParse := pflag.NewFlagSet("flagsFlags", pflag.ContinueOnError)
+	flagsToParse.Bool("init", false, "sets the init flag to true")
 	flagsToParse.Bool("edit", false, "sets the edit flag to true")
 
 	if err := flagsToParse.Parse(pr.Args); err != nil {
@@ -49,11 +50,16 @@ func metadataCmd(pr *external.PluginRequest) external.PluginResponse {
 		return pluginResponse
 	}
 
+	initFlag, _ := flagsToParse.GetBool("init")
 	editFlag, _ := flagsToParse.GetBool("edit")
 
 	// The Phase 2 Plugins implementation will only ever pass a single boolean flag
-	// argument in the JSON request `args` field. The flag will be `--edit` for `edit`
-	if editFlag {
+	// argument in the JSON request `args` field.
+	if initFlag {
+		// Populate the JSON response `metadata` field with a description
+		// and examples for the `init` subcommand
+		pluginResponse.Metadata = scaffolds.InitMeta
+	} else if editFlag {
 		// Populate the JSON response `metadata` field with a description
 		// and examples for the `edit` subcommand
 		pluginResponse.Metadata = scaffolds.EditMeta

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/internal/test/plugins/prometheus/kustomization.go

@@ -30,7 +30,7 @@ func NewPrometheusKustomization() *PrometheusKustomization {
 }
 
 const prometheusKustomizationTemplate = `resources:
-  - monitor.yaml
+  - prometheus.yaml
 `
 
 // DefaultKustomizationPatch represents a patch to config/default/kustomization.yaml
@@ -47,12 +47,12 @@ func NewDefaultKustomizationPatch() *DefaultKustomizationPatch {
 	}
 }
 
-const defaultKustomizationPatchTemplate = `# [PROMETHEUS] To enable prometheus monitor, uncomment the following line in config/default/kustomization.yaml:
+const defaultKustomizationPatchTemplate = `# [PROMETHEUS] To enable prometheus monitoring, uncomment the following line in config/default/kustomization.yaml:
 #
 # In the resources section, add:
 # - ../prometheus
 #
-# This will include the Prometheus ServiceMonitor in your deployment.
+# This will include the Prometheus instance in your deployment.
 # Make sure you have the Prometheus Operator installed in your cluster.
 #
 # For more information, see: https://github.com/prometheus-operator/prometheus-operator

docs/book/src/simple-external-plugin-tutorial/testdata/sampleexternalplugin/v1/internal/test/plugins/prometheus/prometheus.go

@@ -0,0 +1,132 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+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.
+*/
+package prometheus
+
+import "fmt"
+
+// PrometheusInstance represents a Prometheus instance manifest
+type PrometheusInstance struct {
+	Path    string
+	Content string
+}
+
+// PrometheusOptions allows configuration of the Prometheus instance
+type PrometheusOptions func(*PrometheusInstance)
+
+// WithDomain sets the domain for the Prometheus instance
+func WithDomain(domain string) PrometheusOptions {
+	return func(p *PrometheusInstance) {
+		p.Content = fmt.Sprintf(prometheusTemplate, domain, domain, domain, domain)
+	}
+}
+
+// WithProjectName sets the project name for the Prometheus instance
+func WithProjectName(projectName string) PrometheusOptions {
+	return func(p *PrometheusInstance) {
+		// Project name can be used for labels or naming
+		// For now, we'll use it in a future iteration if needed
+	}
+}
+
+// NewPrometheusInstance creates a new Prometheus instance manifest
+func NewPrometheusInstance(opts ...PrometheusOptions) *PrometheusInstance {
+	p := &PrometheusInstance{
+		Path: "config/prometheus/prometheus.yaml",
+	}
+
+	for _, opt := range opts {
+		opt(p)
+	}
+
+	// Set default content if not set by options
+	if p.Content == "" {
+		p.Content = fmt.Sprintf(prometheusTemplate, "example.com", "example.com", "example.com", "example.com")
+	}
+
+	return p
+}
+
+const prometheusTemplate = `# Prometheus ServiceAccount
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: prometheus
+  namespace: system
+  labels:
+    app.kubernetes.io/name: %s
+    app.kubernetes.io/managed-by: kustomize
+
+---
+# Prometheus ClusterRole
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: prometheus
+  labels:
+    app.kubernetes.io/name: %s
+    app.kubernetes.io/managed-by: kustomize
+rules:
+- apiGroups: [""]
+  resources: ["nodes", "nodes/metrics", "services", "endpoints", "pods"]
+  verbs: ["get", "list", "watch"]
+- apiGroups: [""]
+  resources: ["configmaps"]
+  verbs: ["get"]
+- nonResourceURLs: ["/metrics"]
+  verbs: ["get"]
+
+---
+# Prometheus ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: prometheus
+  labels:
+    app.kubernetes.io/name: %s
+    app.kubernetes.io/managed-by: kustomize
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: prometheus
+subjects:
+- kind: ServiceAccount
+  name: prometheus
+  namespace: system
+
+---
+# Prometheus Instance
+apiVersion: monitoring.coreos.com/v1
+kind: Prometheus
+metadata:
+  name: prometheus
+  namespace: system
+  labels:
+    app.kubernetes.io/name: %s
+    app.kubernetes.io/managed-by: kustomize
+spec:
+  logLevel: debug
+  ruleSelector: {}
+  scrapeInterval: 1m
+  scrapeTimeout: 30s
+  securityContext:
+    runAsNonRoot: true
+    runAsUser: 65534
+    seccompProfile:
+      type: RuntimeDefault
+  serviceAccountName: prometheus
+  serviceDiscoveryRole: EndpointSlice
+  serviceMonitorSelector: {}
+`