Add prefix/suffix support, short ID fallback, unit docs

- config: add Prefix/Suffix fields to Config struct
- systemd: ServiceName/Generate/UnitPath/Install/Uninstall/Enable/Disable/Status all accept prefix+suffix
- runtime: fall back to short container ID (12 chars) when container has no name
- cmd: active, status, install all thread prefix/suffix from config
- systemd/generator_test.go: updated all calls + added TestGenerate_WithPrefixSuffix
- docs/generated-units.md: full examples of every unit type + ordering + naming
- README: updated config docs, prefix/suffix section, link to docs/

systemd/manager.go

@@ -13,26 +13,27 @@ import (
 const systemUnitDir = "/etc/systemd/system"
 
 // UnitPath returns the filesystem path where the .service file should be written.
-func UnitPath(u config.Unit) (string, error) {
+func UnitPath(u config.Unit, prefix, suffix string) (string, error) {
+	svcName := ServiceName(u, prefix, suffix)
 	if u.User == "" {
-		return filepath.Join(systemUnitDir, ServiceName(u)), nil
+		return filepath.Join(systemUnitDir, svcName), nil
 	}
 	// Rootless: write to the user's systemd config dir
 	home, err := userHomeDir(u.User)
 	if err != nil {
 		return "", err
 	}
-	return filepath.Join(home, ".config", "systemd", "user", ServiceName(u)), nil
+	return filepath.Join(home, ".config", "systemd", "user", svcName), nil
 }
 
 // Install writes the .service file for a unit and reloads systemd.
-func Install(u config.Unit) error {
-	content, err := Generate(u)
+func Install(u config.Unit, prefix, suffix string) error {
+	content, err := Generate(u, prefix, suffix)
 	if err != nil {
 		return err
 	}
 
-	path, err := UnitPath(u)
+	path, err := UnitPath(u, prefix, suffix)
 	if err != nil {
 		return err
 	}
@@ -49,8 +50,8 @@ func Install(u config.Unit) error {
 }
 
 // Uninstall removes the .service file for a unit and reloads systemd.
-func Uninstall(u config.Unit) error {
-	path, err := UnitPath(u)
+func Uninstall(u config.Unit, prefix, suffix string) error {
+	path, err := UnitPath(u, prefix, suffix)
 	if err != nil {
 		return err
 	}
@@ -63,18 +64,18 @@ func Uninstall(u config.Unit) error {
 }
 
 // Enable enables and starts a unit.
-func Enable(u config.Unit) error {
-	return systemctl(u.User, "enable", "--now", ServiceName(u))
+func Enable(u config.Unit, prefix, suffix string) error {
+	return systemctl(u.User, "enable", "--now", ServiceName(u, prefix, suffix))
 }
 
 // Disable disables and stops a unit.
-func Disable(u config.Unit) error {
-	return systemctl(u.User, "disable", "--now", ServiceName(u))
+func Disable(u config.Unit, prefix, suffix string) error {
+	return systemctl(u.User, "disable", "--now", ServiceName(u, prefix, suffix))
 }
 
 // Status returns the ActiveState of a unit ("active", "inactive", "failed", "unknown").
-func Status(u config.Unit) string {
-	args := []string{"show", "-p", "ActiveState", "--value", ServiceName(u)}
+func Status(u config.Unit, prefix, suffix string) string {
+	args := []string{"show", "-p", "ActiveState", "--value", ServiceName(u, prefix, suffix)}
 	var out []byte
 	var err error
 
@@ -90,8 +91,8 @@ func Status(u config.Unit) string {
 }
 
 // IsInstalled returns true if the unit file exists on disk.
-func IsInstalled(u config.Unit) bool {
-	path, err := UnitPath(u)
+func IsInstalled(u config.Unit, prefix, suffix string) bool {
+	path, err := UnitPath(u, prefix, suffix)
 	if err != nil {
 		return false
 	}