helm: add arkade chart bump to bump chart versions

README.md

@@ -22,6 +22,7 @@ With over 120 CLIs and 55 Kubernetes apps (charts, manifests, installers) availa
   - [Download CLI tools with arkade](#download-cli-tools-with-arkade)
   - [Install System Packages](#install-system-packages)
   - [Install CLIs during CI with GitHub Actions](#install-clis-during-ci-with-github-actions)
+  - [Bump Helm chart versions](#bump-helm-chart-versions)
   - [Verify and upgrade images in Helm charts](#verify-and-upgrade-images-in-helm-charts)
     - [Upgrade images within a Helm chart](#upgrade-images-within-a-helm-chart)
   - [Verify images within a helm chart](#verify-images-within-a-helm-chart)
@@ -283,6 +284,25 @@ If you just need system applications, you could also try "setup-arkade":
         arkade system install go
 ```
 
+## Bump Helm chart versions
+
+To bump the patch version of your Helm chart, run `arkade chart bump -f ./chart/values.yaml`. This updates the patch component of the version specified in Chart.yaml.
+
+```bash
+arkade chart bump -f ./charts/flagger/values.yaml
+charts/flagger/Chart.yaml 1.36.0 => 1.37.0
+```
+
+By default, the new version is written to stdout. To bump the version in the file, run the above command with the `--write` flag.
+To bump the version in the chart's Chart.yaml only if the chart has any changes, specify the `--check-for-updates` flag:
+
+```bash
+arkade chart bump -f ./charts/flagger/values.yaml --check-for-updates
+no changes detected in charts/flagger/values.yaml; skipping version bump
+```
+
+The directory that contains the Helm chart should be a Git repository. If the flag is specified, the command runs `git diff --exit-code <file>` to figure out if the file has any changes.
+
 ## Verify and upgrade images in Helm charts
 
 There are two commands built into arkade designed for software vendors and open source maintainers.

cmd/chart/bump.go

@@ -0,0 +1,133 @@
+package chart
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/Masterminds/semver"
+	"github.com/alexellis/arkade/pkg/helm"
+	"github.com/alexellis/go-execute/v2"
+	"github.com/spf13/cobra"
+)
+
+const (
+	versionKey        = "version"
+	ChartYamlFileName = "Chart.yaml"
+	ChartYmlFileName  = "Chart.yml"
+)
+
+func MakeBump() *cobra.Command {
+	var command = &cobra.Command{
+		Use:   "bump",
+		Short: "Bump the patch version of the Helm chart.",
+		Long: `Bump the version present in the Chart.yaml of a Helm chart.
+To bump the version only if the chart has changes then specify the
+--check-for-updates flag. If the chart has no changes the command
+returns early with an exit code zero.
+`,
+		Example: `arkade chart bump -f ./chart/values.yaml
+  arkade chart bump -f ./charts/values.yaml --check-for-updates`,
+		SilenceUsage: true,
+	}
+
+	command.Flags().StringP("file", "f", "", "Path to values.yaml file")
+	command.Flags().BoolP("verbose", "v", false, "Verbose output")
+	command.Flags().BoolP("write", "w", false, "Write the updated values back to the file, or stdout when set to false")
+	command.Flags().Bool("check-for-updates", false, "Check for updates to the chart before bumping its version")
+
+	command.RunE = func(cmd *cobra.Command, args []string) error {
+		valuesFile, err := cmd.Flags().GetString("file")
+		if err != nil {
+			return fmt.Errorf("invalid value for --file")
+		}
+		if valuesFile == "" {
+			return fmt.Errorf("flag --file is required")
+		}
+		verbose, _ := cmd.Flags().GetBool("verbose")
+		write, err := cmd.Flags().GetBool("write")
+		if err != nil {
+			return fmt.Errorf("invalid value for --write")
+		}
+		checkForUpdates, err := cmd.Flags().GetBool("check-for-updates")
+		if err != nil {
+			return fmt.Errorf("invalid value for --check-for-updates")
+		}
+
+		chartDir := filepath.Dir(valuesFile)
+		chartYamlPath := filepath.Join(chartDir, ChartYamlFileName)
+
+		// Map with key as the path to Chart.yaml and the value as the parsed contents of Chart.yaml
+		var values helm.ValuesMap
+		// Try to read a Chart.yaml, but if thats unsuccessful then fall back to Chart.yml
+		if values, err = helm.Load(chartYamlPath); err != nil {
+			if verbose {
+				log.Printf("unable to read %s, falling back to Chart.yml\n", chartYamlPath)
+			}
+			chartYamlPath = filepath.Join(chartDir, ChartYmlFileName)
+			if values, err = helm.Load(chartYamlPath); err != nil {
+				return fmt.Errorf("unable to read Chart.yaml or Chart.yml in directory %s", chartDir)
+			}
+		}
+
+		// If the yaml does not contain a `version` key then error out.
+		if val, ok := values[versionKey]; !ok {
+			return fmt.Errorf("unable to find a version in %s", chartYamlPath)
+		} else {
+			version, ok := val.(string)
+			if !ok {
+				log.Printf("unable to find a valid version in %s", chartYamlPath)
+			}
+			if checkForUpdates {
+				absPath, err := filepath.Abs(chartDir)
+				if err != nil {
+					return err
+				}
+
+				// Run `git diff --exit-code <file>` to check if any files in the chart dir changed.
+				// An exit code of 0 indicates that there are no changes, thus we skip bumping the
+				// version of the chart.
+				cmd := execute.ExecTask{
+					Command: "git",
+					Args:    []string{"diff", "--exit-code", "."},
+					Cwd:     absPath,
+				}
+				res, err := cmd.Execute(context.Background())
+				if err != nil {
+					return fmt.Errorf("could not check updates to chart values: %s", err)
+				}
+
+				if res.ExitCode == 0 {
+					fmt.Printf("no changes detected in %s; skipping version bump\n", chartDir)
+					os.Exit(0)
+				}
+			}
+
+			ver, err := semver.NewVersion(version)
+			if err != nil {
+				return fmt.Errorf("%s", err)
+			}
+			newVer := ver.IncPatch()
+			fmt.Printf("%s %s => %s\n", chartYamlPath, ver.String(), newVer.String())
+			if write {
+				if verbose {
+					log.Printf("Bumping version")
+				}
+				update := map[string]string{
+					fmt.Sprintf("%s: %s", versionKey, ver.String()): fmt.Sprintf("%s: %s", versionKey, newVer.String()),
+				}
+				rawChartYaml, err := helm.ReplaceValuesInHelmValuesFile(update, chartYamlPath)
+				if err != nil {
+					return fmt.Errorf("unable to bump chart version in %s", chartYamlPath)
+				}
+				if err = os.WriteFile(chartYamlPath, []byte(rawChartYaml), 0600); err != nil {
+					return fmt.Errorf("unable to write updated yaml to %s", chartYamlPath)
+				}
+			}
+		}
+		return nil
+	}
+	return command
+}

cmd/chart/chart.go

@@ -26,6 +26,7 @@ func MakeChart() *cobra.Command {
 
 	command.AddCommand(MakeVerify())
 	command.AddCommand(MakeUpgrade())
+	command.AddCommand(MakeBump())
 
 	return command
 }