Add version arg to install command

cmd/tk/install.go

@@ -1,13 +1,17 @@
 package main
 
 import (
+	"bufio"
 	"bytes"
 	"context"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"os"
 	"os/exec"
+	"path"
 	"strings"
+	"text/template"
 
 	"github.com/spf13/cobra"
 )
@@ -16,35 +20,49 @@ var installCmd = &cobra.Command{
 	Use:   "install",
 	Short: "Install the toolkit components",
 	Long: `
-The Install command deploys the toolkit components
+The install command deploys the toolkit components
 on the configured Kubernetes cluster in ~/.kube/config`,
-	Example: `  install --manifests github.com/fluxcd/toolkit//manifests/install --dry-run`,
+	Example: `  install --version=master --namespace=gitops-systems`,
 	RunE:    installCmdRun,
 }
 
 var (
 	installDryRun        bool
 	installManifestsPath string
+	installVersion       string
 )
 
 func init() {
 	installCmd.Flags().BoolVarP(&installDryRun, "dry-run", "", false,
 		"only print the object that would be applied")
+	installCmd.Flags().StringVarP(&installVersion, "version", "v", "master",
+		"toolkit tag or branch")
 	installCmd.Flags().StringVarP(&installManifestsPath, "manifests", "", "",
-		"path to the manifest directory")
-
+		"path to the manifest directory, dev only")
 	rootCmd.AddCommand(installCmd)
 }
 
 func installCmdRun(cmd *cobra.Command, args []string) error {
-	if installManifestsPath == "" {
-		return fmt.Errorf("no manifests specified")
-	}
-
-	if !strings.HasPrefix(installManifestsPath, "github.com/") {
+	kustomizePath := ""
+	if installVersion == "" && !strings.HasPrefix(installManifestsPath, "github.com/") {
 		if _, err := os.Stat(installManifestsPath); err != nil {
 			return fmt.Errorf("manifests not found: %w", err)
 		}
+		kustomizePath = installManifestsPath
+	}
+
+	tmpDir, err := ioutil.TempDir("", namespace)
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(tmpDir)
+
+	if kustomizePath == "" {
+		err = generateInstall(tmpDir)
+		if err != nil {
+			return err
+		}
+		kustomizePath = tmpDir
 	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
@@ -55,7 +73,7 @@ func installCmdRun(cmd *cobra.Command, args []string) error {
 		dryRun = "--dry-run=client"
 	}
 	command := fmt.Sprintf("kustomize build %s | kubectl apply -f- %s",
-		installManifestsPath, dryRun)
+		kustomizePath, dryRun)
 	c := exec.CommandContext(ctx, "/bin/sh", "-c", command)
 
 	var stdoutBuf, stderrBuf bytes.Buffer
@@ -63,7 +81,7 @@ func installCmdRun(cmd *cobra.Command, args []string) error {
 	c.Stderr = io.MultiWriter(os.Stderr, &stderrBuf)
 
 	logAction("installing components in %s namespace", namespace)
-	err := c.Run()
+	err = c.Run()
 	if err != nil {
 		logFailure("install failed")
 		os.Exit(1)
@@ -91,3 +109,144 @@ func installCmdRun(cmd *cobra.Command, args []string) error {
 	logSuccess("install finished")
 	return nil
 }
+
+var namespaceTmpl = `---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: {{.}}
+`
+
+var labelsTmpl = `---
+apiVersion: builtin
+kind: LabelTransformer
+metadata:
+  name: labels
+labels:
+  app.kubernetes.io/instance: {{.}}
+fieldSpecs:
+  - path: metadata/labels
+    create: true
+`
+
+var kustomizationTmpl = `---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+namespace: {{.Namespace}}
+transformers:
+  - labels.yaml
+resources:
+  - namespace.yaml
+  - roles
+  - github.com/fluxcd/toolkit/manifests/bases/source-controller?ref={{.Version}}
+  - github.com/fluxcd/toolkit/manifests/bases/kustomize-controller?ref={{.Version}}
+  - github.com/fluxcd/toolkit/manifests/policies?ref={{.Version}}
+`
+
+var kustomizationRolesTmpl = `---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - github.com/fluxcd/toolkit/manifests/rbac?ref={{.Version}}
+nameSuffix: -{{.Namespace}}
+`
+
+func generateInstall(tmpDir string) error {
+	logAction("generating install manifests for %s namespace", namespace)
+
+	nst, err := template.New("tmpl").Parse(namespaceTmpl)
+	if err != nil {
+		return fmt.Errorf("template parse error: %w", err)
+	}
+
+	ns, err := execTemplate(nst, namespace)
+	if err != nil {
+		return err
+	}
+
+	if err := writeToFile(path.Join(tmpDir, "namespace.yaml"), ns); err != nil {
+		return err
+	}
+
+	labelst, err := template.New("tmpl").Parse(labelsTmpl)
+	if err != nil {
+		return fmt.Errorf("template parse error: %w", err)
+	}
+
+	labels, err := execTemplate(labelst, namespace)
+	if err != nil {
+		return err
+	}
+
+	if err := writeToFile(path.Join(tmpDir, "labels.yaml"), labels); err != nil {
+		return err
+	}
+
+	model := struct {
+		Version   string
+		Namespace string
+	}{
+		Version:   installVersion,
+		Namespace: namespace,
+	}
+
+	kt, err := template.New("tmpl").Parse(kustomizationTmpl)
+	if err != nil {
+		return fmt.Errorf("template parse error: %w", err)
+	}
+
+	k, err := execTemplate(kt, model)
+	if err != nil {
+		return err
+	}
+
+	if err := writeToFile(path.Join(tmpDir, "kustomization.yaml"), k); err != nil {
+		return err
+	}
+
+	krt, err := template.New("tmpl").Parse(kustomizationRolesTmpl)
+	if err != nil {
+		return fmt.Errorf("template parse error: %w", err)
+	}
+
+	kr, err := execTemplate(krt, model)
+	if err != nil {
+		return err
+	}
+
+	if err := os.MkdirAll(path.Join(tmpDir, "roles"), os.ModePerm); err != nil {
+		return err
+	}
+
+	if err := writeToFile(path.Join(tmpDir, "roles/kustomization.yaml"), kr); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func execTemplate(t *template.Template, obj interface{}) (string, error) {
+	var data bytes.Buffer
+	writer := bufio.NewWriter(&data)
+	if err := t.Execute(writer, obj); err != nil {
+		return "", fmt.Errorf("template execution failed: %w", err)
+	}
+	if err := writer.Flush(); err != nil {
+		return "", fmt.Errorf("template flush failed: %w", err)
+	}
+	return data.String(), nil
+}
+
+func writeToFile(filename string, data string) error {
+	file, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	_, err = io.WriteString(file, data)
+	if err != nil {
+		return err
+	}
+	return file.Sync()
+}