Added support for ssh signed commits and completed gpg signed commit work

Signed-off-by: Dustin Lactin <[email protected]>

Author: dlactin

.github/actions/spelling/expect.txt

@@ -2,6 +2,9 @@
 aeece
 Artifactory
 applicationid
+atlassian
+Bitbucket
+bitbucketserver
 bacd
 CVE
 credref
@@ -11,7 +14,9 @@ eec
 fbd
 ffb
 gitlab
+GPG
 helmvalues
+html
 installationid
 jfrog
 mep

cmd/main.go

@@ -45,6 +45,8 @@ type ImageUpdaterConfig struct {
 	GitCommitUser       string
 	GitCommitMail       string
 	GitCommitMessage    *template.Template
+	GitCommitSigningKey string
+	GitCommitSignOff    bool
 	DisableKubeEvents   bool
 	GitCreds            git.CredsStore
 }

cmd/run.go

@@ -240,6 +240,8 @@ 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(&cfg.GitCommitSigningKey, "git-commit-signing-key", env.GetStringVal("GIT_COMMIT_SIGNING_KEY", ""), "GnuPG key ID or path to Public SSH Key used to sign the commits")
+	runCmd.Flags().BoolVar(&cfg.GitCommitSignOff, "git-commit-sign-off", env.GetBoolVal("GIT_COMMIT_SIGN_OFF", false), "Whether to sign-off 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")
 
@@ -327,6 +329,8 @@ func runImageUpdater(cfg *ImageUpdaterConfig, warmUp bool) (argocd.ImageUpdaterR
 				GitCommitUser:     cfg.GitCommitUser,
 				GitCommitEmail:    cfg.GitCommitMail,
 				GitCommitMessage:  cfg.GitCommitMessage,
+				GitCommitSigningKey: cfg.GitCommitSigningKey,
+				GitCommitSignOff:    cfg.GitCommitSignOff,
 				DisableKubeEvents: cfg.DisableKubeEvents,
 				GitCreds:          cfg.GitCreds,
 			}

docs/basics/update-methods.md

@@ -153,7 +153,8 @@ format. To create such a secret from an existing private key, you can use
 
 ```bash
 kubectl -n argocd-image-updater create secret generic git-creds \
-  --from-file=sshPrivateKey=~/.ssh/id_rsa
+  --from-file=sshPrivateKey=~/.ssh/id_rsa \
+  --from-file=sshPublicKey=~/.ssh/id_rsa.pub \
 ```
 
 ### <a name="method-git-repository"></a>Specifying a repository when using a Helm repository in repoURL
@@ -247,6 +248,52 @@ as the author. You can override the author using the
 `git.user` and `git.email`
 in the `argocd-image-updater-config` ConfigMap.
 
+### <a name="method-git-commit-signing"></a>Enabling commit signature verification using an SSH or GPG key
+Commit signing requires the repository be accessed using HTTPS or SSH with a user account.
+Repositories accessed using a GitHub App can not be verified when using the git command line at this time.
+
+Each Git commit associated with an author's name and email address can be signed via a public SSH key or GPG key.
+Commit signing requires a bot account with a GPG or SSH key and the username and email address configured to match the bot account.
+
+Your preferred signing key must be associated with your bot account. See provider documentation for further details:
+* [GitHub](https://docs.github.com/en/authentication/managing-commit-signature-verification/about-commit-signature-verification)
+* [GitLab](https://docs.gitlab.com/ee/user/project/repository/signed_commits/)
+* [Bitbucket](https://confluence.atlassian.com/bitbucketserver/controlling-access-to-code-776639770.html)
+
+Commit Sign Off can be enabled by setting `git.commit-sign-off: "true"`
+
+**SSH:**
+
+Both private and public keys must be mounted and accessible on the `argocd-image-updater` pod.
+
+Set `git.commit-signing-key` `argocd-image-updater-config` ConfigMap to the path of your public key:
+
+```yaml
+data:
+  git.commit-sign-off: "true"
+  git.commit-signing-key: /app/.ssh/id_rsa.pub
+```
+
+The matching private key must be available in the same location.
+
+Create a new SSH secret or add the public key to your existing SSH secret:
+```bash
+kubectl -n argocd-image-updater create secret generic ssh-git-creds \
+  --from-file=sshPrivateKey=~/.ssh/id_rsa \
+  --from-file=sshPublicKey=~/.ssh/id_rsa.pub
+```
+
+**GPG:**
+
+The GPG private key must be installed and available in the `argocd-image-updater` pod.
+Set `git.commit-signing-key` in the `argocd-image-updater-config` ConfigMap to the GPG key ID you want to use:
+
+```yaml
+data:
+  git.commit-sign-off: "true"
+  git.commit-signing-key: 3AA5C34371567BD2
+```
+
 ### <a name="method-git-commit-message"></a>Changing the Git commit message
 
 You can change the default commit message used by Argo CD Image Updater to some

ext/git/client.go

@@ -82,6 +82,7 @@ type Client interface {
 	Add(path string) error
 	SymRefToBranch(symRef string) (string, error)
 	Config(username string, email string) error
+	SigningConfig(signingkey string) error
 }
 
 type EventHandlers struct {

ext/git/mocks/Client.go

@@ -3,6 +3,7 @@ package git
 import (
 	"fmt"
 	"os/exec"
+	"regexp"
 	"strings"
 
 	"github.com/argoproj-labs/argocd-image-updater/pkg/log"
@@ -14,7 +15,7 @@ type CommitOptions struct {
 	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 holds a GnuPG key ID or path to Public SSH Key used to sign the commit with (-S option)
 	SigningKey string
 	// SignOff specifies whether to sign-off a commit (-s option)
 	SignOff bool
@@ -33,7 +34,16 @@ func (m *nativeGitClient) Commit(pathSpec string, opts *CommitOptions) error {
 		args = append(args, "-a")
 	}
 	if opts.SigningKey != "" {
-		args = append(args, "-S", opts.SigningKey)
+		// Check if SiginingKey is a GPG key or Public SSH Key
+		keyCheck, err := regexp.MatchString(".*pub$", opts.SigningKey)
+		if err != nil {
+			return fmt.Errorf("could not validate Signing Key as GPG or Public SSH Key: %v", err)
+		}
+		if keyCheck {
+			args = append(args, "-S")
+		} else {
+			args = append(args, "-S", opts.SigningKey)
+		}
 	}
 	if opts.SignOff {
 		args = append(args, "-s")
@@ -147,3 +157,28 @@ func (m *nativeGitClient) runCredentialedCmdWithOutput(args ...string) (string,
 	cmd.Env = append(cmd.Env, environ...)
 	return m.runCmdOutput(cmd, runOpts{})
 }
+
+// SigningConfig configures commit signing for the repository
+func (m *nativeGitClient) SigningConfig(signingkey string) error {
+	// Check if SiginingKey is a GPG key or Public SSH Key
+	keyCheck, err := regexp.MatchString(".*pub$", signingkey)
+	if err != nil {
+		return fmt.Errorf("could not validate Signing Key as GPG or Public SSH Key: %v", err)
+	}
+	if keyCheck {
+		// Setting the GPG format to ssh
+		log.Warnf("Setting GPG Format to SSH")
+		_, err = m.runCmd("config", "gpg.format", "ssh")
+		if err != nil {
+			return fmt.Errorf("could not set gpg format to ssh: %v", err)
+		}
+		// Setting Public SSH Key as our signing key
+		// SSH Keys can not currently be set via cli flag
+		_, err = m.runCmd("config", "user.signingkey", signingkey)
+		if err != nil {
+			return fmt.Errorf("could not set git signing key: %v", err)
+		}
+	}
+
+	return nil
+}

ext/git/writer.go

@@ -77,6 +77,18 @@ spec:
               name: argocd-image-updater-config
               key: git.email
               optional: true
+        - name: GIT_COMMIT_SIGNING_KEY
+          valueFrom:
+            configMapKeyRef:
+              key: git.commit-signing-key
+              name: argocd-image-updater-config
+              optional: true
+        - name: GIT_COMMIT_SIGN_OFF
+          valueFrom:
+            configMapKeyRef:
+              key: git.commit-sign-off
+              name: argocd-image-updater-config
+              optional: true
         - name: IMAGE_UPDATER_KUBE_EVENTS
           valueFrom:
             configMapKeyRef:
@@ -116,6 +128,14 @@ spec:
           name: ssh-config
         - mountPath: /tmp
           name: tmp
+        - name: ssh-signing-key
+          mountPath: /app/.ssh/id_rsa
+          readOnly: true
+          subPath: sshPrivateKey
+        - name: ssh-signing-key
+          mountPath: /app/.ssh/id_rsa.pub
+          readOnly: true
+          subPath: sshPublicKey
       serviceAccountName: argocd-image-updater
       volumes:
       - configMap:
@@ -135,5 +155,9 @@ spec:
           name: argocd-image-updater-ssh-config
           optional: true
         name: ssh-config
+      - name: ssh-signing-key
+        secret:
+          secretName: ssh-git-creds
+        optional: true
       - emptyDir: {}
         name: tmp

manifests/base/deployment/argocd-image-updater-deployment.yaml

@@ -158,6 +158,18 @@ spec:
               key: git.email
               name: argocd-image-updater-config
               optional: true
+        - name: GIT_COMMIT_SIGNING_KEY
+          valueFrom:
+            configMapKeyRef:
+              key: git.commit-signing-key
+              name: argocd-image-updater-config
+              optional: true
+        - name: GIT_COMMIT_SIGN_OFF
+          valueFrom:
+            configMapKeyRef:
+              key: git.commit-sign-off
+              name: argocd-image-updater-config
+              optional: true
         - name: IMAGE_UPDATER_KUBE_EVENTS
           valueFrom:
             configMapKeyRef:
@@ -199,6 +211,14 @@ spec:
           name: ssh-config
         - mountPath: /tmp
           name: tmp
+        - mountPath: /app/.ssh/id_rsa
+          name: ssh-signing-key
+          readOnly: true
+          subPath: sshPrivateKey
+        - mountPath: /app/.ssh/id_rsa.pub
+          name: ssh-signing-key
+          readOnly: true
+          subPath: sshPublicKey
       serviceAccountName: argocd-image-updater
       volumes:
       - configMap:
@@ -218,5 +238,9 @@ spec:
           name: argocd-image-updater-ssh-config
           optional: true
         name: ssh-config
+      - name: ssh-signing-key
+        optional: true
+        secret:
+          secretName: ssh-git-creds
       - emptyDir: {}
         name: tmp

manifests/install.yaml

@@ -169,6 +169,14 @@ func commitChangesGit(app *v1alpha1.Application, wbc *WriteBackConfig, changeLis
 		}
 	}
 
+	// Set commit signing configuration
+	if wbc.GitCommitSigningKey != "" {
+		err = gitC.SigningConfig(wbc.GitCommitSigningKey)
+		if err != nil {
+			return err
+		}
+	}
+
 	// The branch to checkout is either a configured branch in the write-back
 	// config, or taken from the application spec's targetRevision. If the
 	// target revision is set to the special value HEAD, or is the empty
@@ -234,6 +242,12 @@ func commitChangesGit(app *v1alpha1.Application, wbc *WriteBackConfig, changeLis
 		defer os.Remove(cm.Name())
 	}
 
+	if wbc.GitCommitSigningKey != "" {
+		commitOpts.SigningKey = wbc.GitCommitSigningKey
+	}
+
+	commitOpts.SignOff = wbc.GitCommitSignOff
+
 	err = gitC.Commit("", commitOpts)
 	if err != nil {
 		return err