provide default git configuration in .gitconfig instead of environmen…

…t variables
coder · dwahler · Jul 14, 2022 · Jul 14, 2022 · Jul 14, 2022 · Jul 14, 2022
commit 5a2ea9bc3ca8d0f94d7fbec68877090084ffc0a5
diff --git a/agent/agent.go b/agent/agent.go
@@ -66,6 +66,7 @@ type Metadata struct {
 	EnvironmentVariables map[string]string  `json:"environment_variables"`
 	StartupScript        string             `json:"startup_script"`
 	Directory            string             `json:"directory"`
+	GitConfigPath        string             `json:"git_config_path"`
 }
 
 type WireguardPublicKeys struct {
@@ -193,7 +194,19 @@ func (a *agent) run(ctx context.Context) {
 }
 
 func (a *agent) performInitialSetup(ctx context.Context, metadata *Metadata) error {
-	err := a.runStartupScript(ctx, metadata.StartupScript)
+	err := setupGitconfig(ctx, metadata.GitConfigPath, map[string]string{
+		"user.name":  metadata.OwnerUsername,
+		"user.email": metadata.OwnerEmail,
+	})
+	if errors.Is(err, context.Canceled) {
+		return err
+	}
+	if err != nil {
+		// failure to set up gitconfig shouldn't prevent the startup script from running
+		a.logger.Warn(ctx, "git autoconfiguration failed", slog.Error(err))
+	}
+
+	err = a.runStartupScript(ctx, metadata.StartupScript)
 	if err != nil {
 		return xerrors.Errorf("agent script failed: %w", err)
 	}
@@ -402,12 +415,6 @@ func (a *agent) createCommand(ctx context.Context, rawCommand string, env []stri
 	// If using backslashes, it's unable to find the executable.
 	unixExecutablePath := strings.ReplaceAll(executablePath, "\\", "/")
 	cmd.Env = append(cmd.Env, fmt.Sprintf(`GIT_SSH_COMMAND=%s gitssh --`, unixExecutablePath))
-	// These prevent the user from having to specify _anything_ to successfully commit.
-	// Both author and committer must be set!
-	cmd.Env = append(cmd.Env, fmt.Sprintf(`GIT_AUTHOR_EMAIL=%s`, metadata.OwnerEmail))
-	cmd.Env = append(cmd.Env, fmt.Sprintf(`GIT_COMMITTER_EMAIL=%s`, metadata.OwnerEmail))
-	cmd.Env = append(cmd.Env, fmt.Sprintf(`GIT_AUTHOR_NAME=%s`, metadata.OwnerUsername))
-	cmd.Env = append(cmd.Env, fmt.Sprintf(`GIT_COMMITTER_NAME=%s`, metadata.OwnerUsername))
 
 	// Load environment variables passed via the agent.
 	// These should override all variables we manually specify.

diff --git a/agent/agent_test.go b/agent/agent_test.go
@@ -216,6 +216,25 @@ func TestAgent(t *testing.T) {
 		require.Equal(t, content, strings.TrimSpace(gotContent))
 	})
 
+	t.Run("GitAutoconfig", func(t *testing.T) {
+		t.Parallel()
+		configPath := filepath.Join(os.TempDir(), "gitconfig")
+
+		initialContent := "[user]\nemail = [email protected]\n"
+		err := os.WriteFile(configPath, []byte(initialContent), 0600)
+		require.NoError(t, err)
+
+		setupAgent(t, agent.Metadata{
+			OwnerUsername: "Kermit the Frog",
+			OwnerEmail:    "[email protected]",
+			GitConfigPath: configPath,
+		}, 0)
+
+		gotContent := readFileContents(t, configPath)
+		require.Contains(t, gotContent, "name = Kermit the Frog")
+		require.Contains(t, gotContent, "email = [email protected]")
+	})
+
 	t.Run("ReconnectingPTY", func(t *testing.T) {
 		t.Parallel()
 		if runtime.GOOS == "windows" {

diff --git a/agent/gitconfig.go b/agent/gitconfig.go
@@ -0,0 +1,59 @@
+package agent
+
+import (
+	"context"
+	"os/exec"
+	"os/user"
+	"strings"
+
+	"golang.org/x/xerrors"
+)
+
+var errNoGitAvailable = xerrors.New("Git does not seem to be installed")
+
+func setupGitconfig(ctx context.Context, configPath string, params map[string]string) error {
+	if configPath == "" {
+		return nil
+	}
+	if strings.HasPrefix(configPath, "~/") {
+		currentUser, err := user.Current()
+		if err != nil {
+			return xerrors.Errorf("get current user: %w", err)
+		}
+		configPath = currentUser.HomeDir + "/" + configPath[2:]
+	}
+
+	cmd := exec.CommandContext(ctx, "git", "--version")
+	err := cmd.Run()
+	if err != nil {
+		return errNoGitAvailable
+	}
+
+	for name, value := range params {
+		err = setGitConfigIfUnset(ctx, configPath, name, value)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func setGitConfigIfUnset(ctx context.Context, configPath, name, value string) error {
+	cmd := exec.CommandContext(ctx, "git", "config", "--file", configPath, "--get", name)
+	err := cmd.Run()
+	if err == nil {
+		// an exit status of 0 means the value exists, so there's nothing to do
+		return nil
+	}
+	// an exit status of 1 means the value is unset
+	if cmd.ProcessState.ExitCode() != 1 {
+		return xerrors.Errorf("getting %s: %w", name, err)
+	}
+
+	cmd = exec.CommandContext(ctx, "git", "config", "--file", configPath, "--add", name, value)
+	_, err = cmd.Output()
+	if err != nil {
+		return xerrors.Errorf("setting %s=%s: %w", name, value, err)
+	}
+	return nil
+}
diff --git a/coderd/workspaceagents.go b/coderd/workspaceagents.go
@@ -178,6 +178,7 @@ func (api *API) workspaceAgentMetadata(rw http.ResponseWriter, r *http.Request)
 		EnvironmentVariables: apiAgent.EnvironmentVariables,
 		StartupScript:        apiAgent.StartupScript,
 		Directory:            apiAgent.Directory,
+		GitConfigPath:        "~/.gitconfig",
 	})
 }