Enable portable mode by reading a config file 'gropple.yml' from the current directory, if present. Closes #13

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to this project will be documented in this file.
 - Add a stop button in the popup to abort a download (Linux/Mac only)
 - Move included JS to local app instead of accessing from a CDN
 - Make the simultaneous download limit apply to each unique domain
+- Support "portable" mode, reading gropple.yml from the current directory, if present
 
 ## [v0.5.3] - 2021-11-21
 

README.md

@@ -75,6 +75,13 @@ While gropple will use your `PATH` to find the executable, you can also specify
 instead. Note that any tools that the downloader calls itself (for instance, ffmpeg) will 
 probably need to be available on your path.
 
+## Portable mode
+
+If you'd like to use gropple from a USB stick or similar, copy the config file from
+it's default location (shown when you start gropple) to the same location as the binary, and rename it to `gropple.yml`. 
+
+If that file is present in the same directory as the binary, it will be used instead.
+
 ## Problems
 
 Most download problems are probably diagnosable via the log - check in the popup window and scroll

config/config.go

@@ -40,7 +40,8 @@ type Config struct {
 // ConfigService is a struct to handle configuration requests, allowing for the
 // location that config files are loaded to be customised.
 type ConfigService struct {
-	Config *Config
+	Config     *Config
+	ConfigPath string
 }
 
 func (cs *ConfigService) LoadTestConfig() {
@@ -166,9 +167,17 @@ func (c *Config) UpdateFromJSON(j []byte) error {
 	return nil
 }
 
-// configPath returns the full path to the config file (which may or may
-// not yet exist) and also creates the subdir if needed (one level)
-func (cs *ConfigService) configPath() string {
+// DetermineConfigDir determines where the config is (or should be) stored.
+func (cs *ConfigService) DetermineConfigDir() {
+	// check current directory first, for a file called gropple.yml
+	_, err := os.Stat("gropple.yml")
+	if err == nil {
+		// exists in current directory, use that.
+		cs.ConfigPath = "gropple.yml"
+		return
+	}
+
+	// otherwise fall back to using the UserConfigDir
 	dir, err := os.UserConfigDir()
 	if err != nil {
 		log.Fatalf("cannot find a directory to store config: %v", err)
@@ -186,13 +195,13 @@ func (cs *ConfigService) configPath() string {
 	}
 
 	fullFilename := fullPath + string(os.PathSeparator) + "config.yml"
-	return fullFilename
+	cs.ConfigPath = fullFilename
 }
 
 // ConfigFileExists checks if the config file already exists, and also checks
 // if there is an error accessing it
 func (cs *ConfigService) ConfigFileExists() (bool, error) {
-	path := cs.configPath()
+	path := cs.ConfigPath
 	info, err := os.Stat(path)
 	if os.IsNotExist(err) {
 		return false, nil
@@ -209,7 +218,7 @@ func (cs *ConfigService) ConfigFileExists() (bool, error) {
 // LoadConfig loads the configuration from disk, migrating and updating it to the
 // latest version if needed.
 func (cs *ConfigService) LoadConfig() error {
-	path := cs.configPath()
+	path := cs.ConfigPath
 	b, err := os.ReadFile(path)
 	if err != nil {
 		return fmt.Errorf("Could not read config '%s': %v", path, err)
@@ -246,18 +255,16 @@ func (cs *ConfigService) WriteConfig() {
 		panic(err)
 	}
 
-	path := cs.configPath()
+	path := cs.ConfigPath
 	file, err := os.Create(
 		path,
 	)
 
 	if err != nil {
-		log.Fatalf("Could not open config file")
+		log.Fatalf("Could not open config file %s: %s", path, err)
 	}
 	defer file.Close()
 
 	file.Write(s)
 	file.Close()
-
-	log.Printf("Wrote configuration out to %s", path)
 }

main.go

@@ -39,20 +39,26 @@ type errorResponse struct {
 }
 
 func main() {
-	cs := config.ConfigService{}
-	exists, err := cs.ConfigFileExists()
+	log.Printf("Starting gropple %s - https://github.com/tardisx/gropple", versionInfo.CurrentVersion)
+
+	configService = &config.ConfigService{}
+	configService.DetermineConfigDir()
+	exists, err := configService.ConfigFileExists()
 	if err != nil {
 		log.Fatal(err)
 	}
 	if !exists {
 		log.Print("No config file - creating default config")
-		cs.LoadDefaultConfig()
-		cs.WriteConfig()
+		configService.LoadDefaultConfig()
+		configService.WriteConfig()
+		log.Printf("Configuration written to %s", configService.ConfigPath)
 	} else {
-		err := cs.LoadConfig()
+		err := configService.LoadConfig()
 		if err != nil {
 			log.Fatal(err)
 		}
+		log.Printf("Configuration loaded from %s", configService.ConfigPath)
+
 	}
 
 	r := mux.NewRouter()
@@ -97,8 +103,7 @@ func main() {
 		}
 	}()
 
-	log.Printf("starting gropple %s - https://github.com/tardisx/gropple", versionInfo.CurrentVersion)
-	log.Printf("go to %s for details on installing the bookmarklet and to check status", configService.Config.Server.Address)
+	log.Printf("Visit %s for details on installing the bookmarklet and to check status", configService.Config.Server.Address)
 	log.Fatal(srv.ListenAndServe())
 
 }

version/version.go

@@ -63,8 +63,6 @@ func (i *Info) canUpgrade() bool {
 		return false
 	}
 
-	log.Printf("We are %s, github is %s", i.CurrentVersion, i.GithubVersion)
-
 	if !semver.IsValid(i.CurrentVersion) {
 		log.Printf("current version %s is invalid", i.CurrentVersion)
 	}