feat: Allow setting custom Git commit messages (#193)

* feat: Support Git commit message templates

Signed-off-by: jannfis <[email protected]>

* More templating

Signed-off-by: jannfis <[email protected]>

* Update

Signed-off-by: jannfis <[email protected]>

* Make TemplateCommitMessage public

Signed-off-by: jannfis <[email protected]>

* Update

Signed-off-by: jannfis <[email protected]>

* Update

Signed-off-by: jannfis <[email protected]>

* Introduce git.CommitOptions{}

Signed-off-by: jannfis <[email protected]>

* Update documentation for commit message templates

Signed-off-by: jannfis <[email protected]>

* Add unit tests

Signed-off-by: jannfis <[email protected]>

* Update manifests

Signed-off-by: jannfis <[email protected]>

* Fix typo in docs

Signed-off-by: jannfis <[email protected]>

* Fix linter issues

Signed-off-by: jannfis <[email protected]>

* Fix linter issues

Signed-off-by: jannfis <[email protected]>

Author: jannfis

cmd/main.go

@@ -2,21 +2,26 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
 	"sync"
+	"text/template"
 	"time"
 
 	"github.com/argoproj-labs/argocd-image-updater/pkg/argocd"
+	"github.com/argoproj-labs/argocd-image-updater/pkg/common"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/env"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/health"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/image"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/kube"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/log"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/metrics"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/registry"
+	"github.com/argoproj-labs/argocd-image-updater/pkg/tag"
 	"github.com/argoproj-labs/argocd-image-updater/pkg/version"
 
 	"github.com/spf13/cobra"
@@ -31,6 +36,9 @@ const defaultArgoCDServerAddr = "argocd-server.argocd"
 // Default path to registry configuration
 const defaultRegistriesConfPath = "/app/config/registries.conf"
 
+// Default path to Git commit message template
+const defaultCommitTemplatePath = "/app/config/commit.template"
+
 const applicationsAPIKindK8S = "kubernetes"
 const applicationsAPIKindArgoCD = "argocd"
 
@@ -51,6 +59,7 @@ type ImageUpdaterConfig struct {
 	AppNamePatterns     []string
 	GitCommitUser       string
 	GitCommitMail       string
+	GitCommitMessage    *template.Template
 	DisableKubeEvents   bool
 }
 
@@ -155,6 +164,7 @@ func runImageUpdater(cfg *ImageUpdaterConfig, warmUp bool) (argocd.ImageUpdaterR
 				DryRun:            dryRun,
 				GitCommitUser:     cfg.GitCommitUser,
 				GitCommitEmail:    cfg.GitCommitMail,
+				GitCommitMessage:  cfg.GitCommitMessage,
 				DisableKubeEvents: cfg.DisableKubeEvents,
 			}
 			res := argocd.UpdateApplication(upconf, syncState)
@@ -203,6 +213,7 @@ func newRootCommand() error {
 	rootCmd.AddCommand(newRunCommand())
 	rootCmd.AddCommand(newVersionCommand())
 	rootCmd.AddCommand(newTestCommand())
+	rootCmd.AddCommand(newTemplateCommand())
 	err := rootCmd.Execute()
 	return err
 }
@@ -231,6 +242,55 @@ func newVersionCommand() *cobra.Command {
 	return versionCmd
 }
 
+func newTemplateCommand() *cobra.Command {
+	var (
+		commitMessageTemplatePath string
+		tplStr                    string
+	)
+	var runCmd = &cobra.Command{
+		Use:   "template [<PATH>]",
+		Short: "Test & render a commit message template",
+		Long: `
+The template command lets you validate your commit message template. It will
+parse the template at given PATH and execute it with a defined set of changes
+so that you can see how it looks like when being templated by Image Updater.
+
+If PATH is not given, will show you the default message that is used.
+`,
+		Run: func(cmd *cobra.Command, args []string) {
+			var tpl *template.Template
+			var err error
+			if len(args) != 1 {
+				tplStr = common.DefaultGitCommitMessage
+			} else {
+				commitMessageTemplatePath = args[0]
+				tplData, err := ioutil.ReadFile(commitMessageTemplatePath)
+				if err != nil {
+					log.Fatalf("%v", err)
+				}
+				tplStr = string(tplData)
+			}
+			if tpl, err = template.New("commitMessage").Parse(tplStr); err != nil {
+				log.Fatalf("could not parse commit message template: %v", err)
+			}
+			chL := []argocd.ChangeEntry{
+				{
+					Image:  image.NewFromIdentifier("gcr.io/example/example:1.0.0"),
+					OldTag: tag.NewImageTag("1.0.0", time.Now(), ""),
+					NewTag: tag.NewImageTag("1.0.1", time.Now(), ""),
+				},
+				{
+					Image:  image.NewFromIdentifier("gcr.io/example/updater@sha256:f2ca1bb6c7e907d06dafe4687e579fce76b37e4e93b7605022da52e6ccc26fd2"),
+					OldTag: tag.NewImageTag("", time.Now(), "sha256:01d09d19c2139a46aebfb577780d123d7396e97201bc7ead210a2ebff8239dee"),
+					NewTag: tag.NewImageTag("", time.Now(), "sha256:7aa7a5359173d05b63cfd682e3c38487f3cb4f7f1d60659fe59fab1505977d4c"),
+				},
+			}
+			fmt.Printf("%s\n", argocd.TemplateCommitMessage(tpl, "example-app", chL))
+		},
+	}
+	return runCmd
+}
+
 func newTestCommand() *cobra.Command {
 	var (
 		semverConstraint  string
@@ -388,6 +448,8 @@ func newRunCommand() *cobra.Command {
 	var kubeConfig string
 	var disableKubernetes bool
 	var warmUpCache bool = true
+	var commitMessagePath string
+	var commitMessageTpl string
 	var runCmd = &cobra.Command{
 		Use:   "run",
 		Short: "Runs the argocd-image-updater with a set of options",
@@ -414,6 +476,33 @@ func newRunCommand() *cobra.Command {
 				getPrintableHealthPort(cfg.HealthPort),
 			)
 
+			// User can specify a path to a template used for Git commit messages
+			if commitMessagePath != "" {
+				tpl, err := ioutil.ReadFile(commitMessagePath)
+				if err != nil {
+					if errors.Is(err, os.ErrNotExist) {
+						log.Warnf("commit message template at %s does not exist, using default", commitMessagePath)
+						commitMessageTpl = common.DefaultGitCommitMessage
+					} else {
+						log.Fatalf("could not read commit message template: %v", err)
+					}
+				} else {
+					commitMessageTpl = string(tpl)
+				}
+			}
+
+			if commitMessageTpl == "" {
+				log.Infof("Using default Git commit messages")
+				commitMessageTpl = common.DefaultGitCommitMessage
+			}
+
+			if tpl, err := template.New("commitMessage").Parse(commitMessageTpl); err != nil {
+				log.Fatalf("could not parse commit message template: %v", err)
+			} else {
+				log.Debugf("Successfully parsed commit message template")
+				cfg.GitCommitMessage = tpl
+			}
+
 			// Load registries configuration early on. We do not consider it a fatal
 			// error when the file does not exist, but we emit a warning.
 			if cfg.RegistriesConf != "" {
@@ -548,6 +637,7 @@ func newRunCommand() *cobra.Command {
 	runCmd.Flags().BoolVar(&warmUpCache, "warmup-cache", true, "whether to perform a cache warm-up on startup")
 	runCmd.Flags().StringVar(&cfg.GitCommitUser, "git-commit-user", env.GetStringVal("GIT_COMMIT_USER", "argocd-image-updater"), "Username to use for Git commits")
 	runCmd.Flags().StringVar(&cfg.GitCommitMail, "git-commit-email", env.GetStringVal("GIT_COMMIT_EMAIL", "[email protected]"), "E-Mail address to use for Git commits")
+	runCmd.Flags().StringVar(&commitMessagePath, "git-commit-message-path", defaultCommitTemplatePath, "Path to a template to use for Git commit messages")
 	runCmd.Flags().BoolVar(&cfg.DisableKubeEvents, "disable-kube-events", env.GetBoolVal("IMAGE_UPDATER_KUBE_EVENTS", false), "Disable kubernetes events")
 
 	return runCmd

docs/configuration/applications.md

@@ -224,3 +224,36 @@ as the author. You can override the author using the
 `--git-commit-user` and `--git-commit-email` command line switches or set
 `git.user` and `git.email`
 in the `argocd-image-updater-config` ConfigMap.
+
+#### Changing the Git commit message
+
+You can change the default commit message used by Argo CD Image Updater to some
+message that best suites your processes and regulations. For this, a simple
+template can be created (evaluating using the `text/template` Golang package)
+and made available through setting the key `git.commit-message-template` in the
+`argocd-image-updater-config` ConfigMap to the template's contents, e.g.
+
+```yaml
+data:
+  git.commit-message-template: |
+    build: automatic update of {{ .AppName }}
+
+    {{ range .AppChanges -}}
+    updates image {{ .Image }} tag '{{ .OldTag }}' to '{{ .NewTag }}'
+    {{ end -}}
+```
+
+Two top-level variables are provided to the template:
+
+* `.AppName` is the name of the application that is being updated
+* `.AppChanges` is a list of changes that were performed by the update. Each
+  entry in this list is a struct providing the following information for
+  each change:
+  * `.Image` holds the full name of the image that was updated
+  * `.OldTag` holds the tag name or SHA digest previous to the update
+  * `.NewTag` holds the tag name or SHA digest that was updated to
+
+In order to test a template before configuring it for use in Image Updater,
+you can store the template you want to use in a temporary file, and then use
+the `argocd-image-updater template /path/to/file` command to render the
+template using pre-defined data and see its outcome on the terminal.

ext/git/client.go

@@ -45,6 +45,18 @@ type Refs struct {
 	// heads and remotes are also refs, but are not needed at this time.
 }
 
+// CommitOptions holds options for a git commit operation
+type CommitOptions struct {
+	// CommitMessageText holds a short commit message (-m option)
+	CommitMessageText string
+	// CommitMessagePath holds the path to a file to be used for the commit message (-F option)
+	CommitMessagePath string
+	// SigningKey holds a GnuPG key ID used to sign the commit with (-S option)
+	SigningKey string
+	// SignOff specifies whether to sign-off a commit (-s option)
+	SignOff bool
+}
+
 // Client is a generic git client interface
 type Client interface {
 	Root() string
@@ -60,7 +72,7 @@ type Client interface {
 	RevisionMetadata(revision string) (*RevisionMetadata, error)
 	VerifyCommitSignature(string) (string, error)
 	Branch(sourceBranch, targetBranch string) error
-	Commit(pathSpec string, message string, signingKey string) error
+	Commit(pathSpec string, opts *CommitOptions) error
 	Push(remote string, branch string, force bool) error
 	Add(path string) error
 	SymRefToBranch(symRef string) (string, error)
@@ -522,17 +534,22 @@ func (m *nativeGitClient) VerifyCommitSignature(revision string) (string, error)
 // used as the commit message, otherwise a default commit message will be used.
 // If signingKey is not the empty string, commit will be signed with the given
 // GPG key.
-func (m *nativeGitClient) Commit(pathSpec string, message string, signingKey string) error {
+func (m *nativeGitClient) Commit(pathSpec string, opts *CommitOptions) error {
 	defaultCommitMsg := "Update parameters"
 	args := []string{"commit"}
 	if pathSpec == "" || pathSpec == "*" {
 		args = append(args, "-a")
 	}
-	if signingKey != "" {
-		args = append(args, "-S", signingKey)
+	if opts.SigningKey != "" {
+		args = append(args, "-S", opts.SigningKey)
+	}
+	if opts.SignOff {
+		args = append(args, "-s")
 	}
-	if message != "" {
-		args = append(args, "-m", message)
+	if opts.CommitMessageText != "" {
+		args = append(args, "-m", opts.CommitMessageText)
+	} else if opts.CommitMessagePath != "" {
+		args = append(args, "-F", opts.CommitMessagePath)
 	} else {
 		args = append(args, "-m", defaultCommitMsg)
 	}

ext/git/mocks/Client.go

@@ -98,14 +98,16 @@ spec:
           initialDelaySeconds: 3
           periodSeconds: 30
         volumeMounts:
-        - name: registries-conf
+        - name: image-updater-conf
           mountPath: /app/config
       serviceAccountName: argocd-image-updater
       volumes:
-      - name: registries-conf
+      - name: image-updater-conf
         configMap:
           name: argocd-image-updater-config
           optional: true
           items:
           - key: registries.conf
             path: registries.conf
+          - key: git.commit-message-template
+            path: commit.template

ext/git/mocks/Creds.go

@@ -174,13 +174,15 @@ spec:
           periodSeconds: 30
         volumeMounts:
         - mountPath: /app/config
-          name: registries-conf
+          name: image-updater-conf
       serviceAccountName: argocd-image-updater
       volumes:
       - configMap:
           items:
           - key: registries.conf
             path: registries.conf
+          - key: git.commit-message-template
+            path: commit.template
           name: argocd-image-updater-config
           optional: true
-        name: registries-conf
+        name: image-updater-conf