cmd: Allow add-package to select version of package

cmd/commands.go

@@ -409,12 +409,13 @@ latest versions. EXPERIMENTAL: May be changed or removed.
 
 	RegisterCommand(Command{
 		Name:  "add-package",
-		Usage: "<packages...>",
+		Usage: "<package[@version]...>",
 		Short: "Adds Caddy packages (EXPERIMENTAL)",
 		Long: `
 Downloads an updated Caddy binary with the specified packages (module/plugin)
-added. Retains existing packages. Returns an error if the any of packages are
-already included. EXPERIMENTAL: May be changed or removed.
+added, with an optional version specified (e.g., "package@version"). Retains
+existing packages. Returns an error if any of the specified packages are already
+included. EXPERIMENTAL: May be changed or removed.
 `,
 		CobraFunc: func(cmd *cobra.Command) {
 			cmd.Flags().BoolP("keep-backup", "k", false, "Keep the backed up binary, instead of deleting it")

cmd/packagesfuncs.go

@@ -46,6 +46,25 @@ func cmdUpgrade(fl Flags) (int, error) {
 	return upgradeBuild(pluginPkgs, fl)
 }
 
+func splitModule(arg string) (module, version string, err error) {
+	const versionSplit = "@"
+
+	// accommodate module paths that have @ in them, but we can only tolerate that if there's also
+	// a version, otherwise we don't know if it's a version separator or part of the file path
+	lastVersionSplit := strings.LastIndex(arg, versionSplit)
+	if lastVersionSplit < 0 {
+		module = arg
+	} else {
+		module, version = arg[:lastVersionSplit], arg[lastVersionSplit+1:]
+	}
+
+	if module == "" {
+		err = fmt.Errorf("module name is required")
+	}
+
+	return
+}
+
 func cmdAddPackage(fl Flags) (int, error) {
 	if len(fl.Args()) == 0 {
 		return caddy.ExitCodeFailedStartup, fmt.Errorf("at least one package name must be specified")
@@ -60,10 +79,15 @@ func cmdAddPackage(fl Flags) (int, error) {
 	}
 
 	for _, arg := range fl.Args() {
-		if _, ok := pluginPkgs[arg]; ok {
+		module, version, err := splitModule(arg)
+		if err != nil {
+			return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid module name: %v", err)
+		}
+		// only allow a version to be specified if it's different from the existing version
+		if _, ok := pluginPkgs[module]; ok && !(version != "" && pluginPkgs[module].Version != version) {
 			return caddy.ExitCodeFailedStartup, fmt.Errorf("package is already added")
 		}
-		pluginPkgs[arg] = struct{}{}
+		pluginPkgs[module] = pluginPackage{Version: version, Path: module}
 	}
 
 	return upgradeBuild(pluginPkgs, fl)
@@ -83,7 +107,11 @@ func cmdRemovePackage(fl Flags) (int, error) {
 	}
 
 	for _, arg := range fl.Args() {
-		if _, ok := pluginPkgs[arg]; !ok {
+		module, _, err := splitModule(arg)
+		if err != nil {
+			return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid module name: %v", err)
+		}
+		if _, ok := pluginPkgs[module]; !ok {
 			// package does not exist
 			return caddy.ExitCodeFailedStartup, fmt.Errorf("package is not added")
 		}
@@ -93,7 +121,7 @@ func cmdRemovePackage(fl Flags) (int, error) {
 	return upgradeBuild(pluginPkgs, fl)
 }
 
-func upgradeBuild(pluginPkgs map[string]struct{}, fl Flags) (int, error) {
+func upgradeBuild(pluginPkgs map[string]pluginPackage, fl Flags) (int, error) {
 	l := caddy.Log()
 
 	thisExecPath, err := os.Executable()
@@ -120,8 +148,8 @@ func upgradeBuild(pluginPkgs map[string]struct{}, fl Flags) (int, error) {
 		"os":   {runtime.GOOS},
 		"arch": {runtime.GOARCH},
 	}
-	for pkg := range pluginPkgs {
-		qs.Add("p", pkg)
+	for _, pkgInfo := range pluginPkgs {
+		qs.Add("p", pkgInfo.String())
 	}
 
 	// initiate the build
@@ -276,14 +304,14 @@ func downloadBuild(qs url.Values) (*http.Response, error) {
 	return resp, nil
 }
 
-func getPluginPackages(modules []moduleInfo) (map[string]struct{}, error) {
-	pluginPkgs := make(map[string]struct{})
+func getPluginPackages(modules []moduleInfo) (map[string]pluginPackage, error) {
+	pluginPkgs := make(map[string]pluginPackage)
 	for _, mod := range modules {
 		if mod.goModule.Replace != nil {
 			return nil, fmt.Errorf("cannot auto-upgrade when Go module has been replaced: %s => %s",
 				mod.goModule.Path, mod.goModule.Replace.Path)
 		}
-		pluginPkgs[mod.goModule.Path] = struct{}{}
+		pluginPkgs[mod.goModule.Path] = pluginPackage{Version: mod.goModule.Version, Path: mod.goModule.Path}
 	}
 	return pluginPkgs, nil
 }
@@ -312,3 +340,15 @@ func writeCaddyBinary(path string, body *io.ReadCloser, fileInfo os.FileInfo) er
 }
 
 const downloadPath = "https://caddyserver.com/api/download"
+
+type pluginPackage struct {
+	Version string
+	Path    string
+}
+
+func (p pluginPackage) String() string {
+	if p.Version == "" {
+		return p.Path
+	}
+	return p.Path + "@" + p.Version
+}