feat: add templating command

CHANGELOG.md

@@ -1,4 +1,6 @@
 # Changes since 1.2.0
+- feat: add templating command
+
 # 1.2.0
 - feat: add wait option
 - feat: apiVersion 1.1 for wait option and add better version handling

cmd/template.go

@@ -0,0 +1,46 @@
+/*
+Copyright © 2023 The Helm Compose 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 cmd
+
+import (
+	"github.com/seacrew/helm-compose/internal/compose"
+	"github.com/seacrew/helm-compose/internal/config"
+	"github.com/spf13/cobra"
+)
+
+var templateCmd = &cobra.Command{
+	Use:   "template [RELEASE ...]",
+	Short: "Render templates for all releases locally and display the output.",
+	Long:  ``,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		cmd.SilenceUsage = true
+
+		if err := compose.CompatibleHelmVersion(); err != nil {
+			return err
+		}
+
+		config, err := config.ParseComposeFile(composeFile)
+		if err != nil {
+			return err
+		}
+
+		return compose.Template(config, args)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(templateCmd)
+}

docs/commands/template.md

@@ -0,0 +1,21 @@
+# helm compose template
+
+Template all kubernetes resources for the releases specified in your `helm-compose.yaml` and print them out to stdout.
+
+## Usage
+
+The following command will print out all kubernetes resources that would be installed or upgraded on stdout.
+
+```
+helm compose template [releases...] [flags]
+```
+
+## Options
+
+```
+Flags:
+  -h, --help   help for template
+
+Global Flags:
+  -f, --file string   Compose configuration file
+```

internal/compose/compose.go

@@ -21,6 +21,7 @@ import (
 
 	cfg "github.com/seacrew/helm-compose/internal/config"
 	prov "github.com/seacrew/helm-compose/internal/provider"
+	"github.com/seacrew/helm-compose/internal/util"
 )
 
 func RunUp(config *cfg.Config) error {
@@ -126,3 +127,28 @@ func GetRevision(rev int, config *cfg.Config) error {
 
 	return nil
 }
+
+func Template(config *cfg.Config, releases []string) error {
+	util.PrintColors = false
+
+	for name, url := range config.Repositories {
+		if err := addHelmRepository(name, url); err != nil {
+			return err
+		}
+	}
+
+	for name, release := range config.Releases {
+		if len(releases) == 0 {
+			templateHelmRelease(name, &release)
+			continue
+		}
+
+		for _, rel := range releases {
+			if rel == name {
+				templateHelmRelease(name, &release)
+			}
+		}
+	}
+
+	return nil
+}

internal/compose/helm.go

@@ -36,25 +36,33 @@ var (
 	minVersion = semver.MustParse("v3.0.0")
 )
 
+type HelmCommand string
+
+const (
+	HELM_UPGRADE   HelmCommand = "upgrade"
+	HELM_UNINSTALL HelmCommand = "uninstall"
+	HELM_TEMPLATE  HelmCommand = "template"
+)
+
 func CompatibleHelmVersion() error {
 	cmd := exec.Command(helm, "version")
 	util.DebugPrint("Executing %s", strings.Join(cmd.Args, " "))
 
 	output, err := cmd.CombinedOutput()
 	if err != nil {
-		return fmt.Errorf("Failed to run `%s version`: %v", os.Getenv("HELM_BIN"), err)
+		return fmt.Errorf("failed to run `%s version`: %v", os.Getenv("HELM_BIN"), err)
 	}
 
 	versionOutput := string(output)
 
 	matches := versionRE.FindStringSubmatch(versionOutput)
 	if matches == nil {
-		return fmt.Errorf("Failed to find version in output %#v", versionOutput)
+		return fmt.Errorf("failed to find version in output %#v", versionOutput)
 	}
 
 	helmVersion, err := semver.NewVersion(matches[1])
 	if err != nil {
-		return fmt.Errorf("Failed to parse version %#v: %v", matches[1], err)
+		return fmt.Errorf("failed to parse version %#v: %v", matches[1], err)
 	}
 
 	if minVersion.GreaterThan(helmVersion) {
@@ -74,10 +82,71 @@ func addHelmRepository(name string, url string) error {
 }
 
 func installHelmRelease(name string, release *cfg.Release) {
+	args, err := createHelmArguments(HELM_UPGRADE, name, release)
+	if err != nil {
+		cp := util.NewColorPrinter(name)
+		cp.Printf("%s |\t\t%s", name, err)
+	}
+
+	helmExec(name, args)
+}
+
+func templateHelmRelease(name string, release *cfg.Release) {
+	args, err := createHelmArguments(HELM_TEMPLATE, name, release)
+	if err != nil {
+		cp := util.NewColorPrinter(name)
+		cp.Printf("# %s |\t\t%s", name, err)
+	}
+
+	helmExec("", args)
+}
+
+func uninstallHelmRelease(name string, release *cfg.Release) {
+	var args []string
+
+	args = append(args, "uninstall")
+
+	if release.Namespace != "" {
+		args = append(args, fmt.Sprintf("--namespace=%s", release.Namespace))
+	}
+
+	if release.KubeConfig != "" {
+		args = append(args, fmt.Sprintf("--kubeconfig=%s", release.KubeConfig))
+	}
+
+	if release.KubeContext != "" {
+		args = append(args, fmt.Sprintf("--kube-context=%s", release.KubeContext))
+	}
+
+	if release.DeletionStrategy != "" {
+		args = append(args, fmt.Sprintf("--cascade=%s", release.DeletionStrategy))
+	}
+
+	if release.DeletionTimeout != "" {
+		args = append(args, fmt.Sprintf("--timeout=%s", release.DeletionTimeout))
+	}
+
+	if release.DeletionNoHooks {
+		args = append(args, "--no-hooks")
+	}
+
+	if release.KeepHistory {
+		args = append(args, "--keep-history")
+	}
+
+	args = append(args, name)
+
+	helmExec(name, args)
+}
+
+func createHelmArguments(command HelmCommand, name string, release *cfg.Release) ([]string, error) {
 	var args []string
 
-	args = append(args, "upgrade")
-	args = append(args, "--install")
+	args = append(args, string(command))
+
+	if command == HELM_UPGRADE {
+		args = append(args, "--install")
+	}
 
 	if release.ChartVersion != "" {
 		args = append(args, fmt.Sprintf("--version=%s", release.ChartVersion))
@@ -162,9 +231,7 @@ func installHelmRelease(name string, release *cfg.Release) {
 		data := util.ConvertJson(release.Values[key])
 		values, err := json.Marshal(data)
 		if err != nil {
-			cp := util.NewColorPrinter(name)
-			cp.Printf("%s |\t\t%s", name, err)
-			return
+			return nil, err
 		}
 
 		jsonValues = append(jsonValues, fmt.Sprintf("%s=%s", key, values))
@@ -177,45 +244,7 @@ func installHelmRelease(name string, release *cfg.Release) {
 	args = append(args, name)
 	args = append(args, release.Chart)
 
-	helmExec(name, args)
-}
-
-func uninstallHelmRelease(name string, release *cfg.Release) {
-	var args []string
-
-	args = append(args, "uninstall")
-
-	if release.Namespace != "" {
-		args = append(args, fmt.Sprintf("--namespace=%s", release.Namespace))
-	}
-
-	if release.KubeConfig != "" {
-		args = append(args, fmt.Sprintf("--kubeconfig=%s", release.KubeConfig))
-	}
-
-	if release.KubeContext != "" {
-		args = append(args, fmt.Sprintf("--kube-context=%s", release.KubeContext))
-	}
-
-	if release.DeletionStrategy != "" {
-		args = append(args, fmt.Sprintf("--cascade=%s", release.DeletionStrategy))
-	}
-
-	if release.DeletionTimeout != "" {
-		args = append(args, fmt.Sprintf("--timeout=%s", release.DeletionTimeout))
-	}
-
-	if release.DeletionNoHooks {
-		args = append(args, "--no-hooks")
-	}
-
-	if release.KeepHistory {
-		args = append(args, "--keep-history")
-	}
-
-	args = append(args, name)
-
-	helmExec(name, args)
+	return args, nil
 }
 
 func helmExec(name string, args []string) {
@@ -224,7 +253,11 @@ func helmExec(name string, args []string) {
 
 	scanner := bufio.NewScanner(strings.NewReader(output))
 	for scanner.Scan() {
-		cp.Printf("%s |\t\t%s", name, scanner.Text())
+		if len(name) == 0 {
+			fmt.Printf("%s\n", scanner.Text())
+		} else {
+			cp.Printf("%s |\t\t%s", name, scanner.Text())
+		}
 	}
 
 	err := scanner.Err()

internal/util/colors.go

@@ -27,6 +27,8 @@ type ColorPrinter struct {
 	colorFunc func(...interface{}) string
 }
 
+var PrintColors = true
+
 func NewColorPrinter(s string) *ColorPrinter {
 	c := hashColor(s)
 	return &ColorPrinter{
@@ -35,7 +37,12 @@ func NewColorPrinter(s string) *ColorPrinter {
 }
 
 func (c ColorPrinter) Printf(format string, a ...any) {
-	fmt.Printf(c.colorFunc(format)+"\n", a...)
+	if PrintColors {
+		fmt.Printf(c.colorFunc(format)+"\n", a...)
+		return
+	}
+
+	fmt.Printf(format+"\n", a...)
 }
 
 var colorFuncs [](func(...interface{}) string) = [](func(...interface{}) string){