package xdsconfig import ( "encoding/json" "os" "os/user" "path" "path/filepath" "regexp" "strings" ) type SyncThingConf struct { Home string `json:"home"` GuiAddress string `json:"gui-address"` GuiAPIKey string `json:"gui-apikey"` } type FileConfig struct { WebAppDir string `json:"webAppDir"` ShareRootDir string `json:"shareRootDir"` HTTPPort string `json:"httpPort"` SThgConf SyncThingConf `json:"syncthing"` } // getConfigFromFile reads configuration from a config file. // Order to determine which config file is used: // 1/ from command line option: "--config myConfig.json" // 2/ $HOME/.xds/config.json file // 3/ /config.json file func updateConfigFromFile(c *Config, confFile string) error { searchIn := make([]string, 0, 3) if confFile != "" { searchIn = append(searchIn, confFile) } if usr, err := user.Current(); err == nil { searchIn = append(searchIn, path.Join(usr.HomeDir, ".xds", "config.json")) } cwd, err := os.Getwd() if err == nil { searchIn = append(searchIn, path.Join(cwd, "config.json")) } exePath, err := filepath.Abs(filepath.Dir(os.Args[0])) if err == nil { searchIn = append(searchIn, path.Join(exePath, "config.json")) } var cFile *string for _, p := range searchIn { if _, err := os.Stat(p); err == nil { cFile = &p break } } if cFile == nil { // No config file found return nil } // TODO move on viper package to support comments in JSON and also // bind with flags (command line options) // see https://github.com/spf13/viper#working-with-flags fd, _ := os.Open(*cFile) defer fd.Close() fCfg := FileConfig{} if err := json.NewDecoder(fd).Decode(&fCfg); err != nil { return err } c.fileConf = fCfg // Support environment variables (IOW ${MY_ENV_VAR} syntax) in config.json // TODO: better to use reflect package to iterate on fields and be more generic fCfg.WebAppDir = path.Clean(resolveEnvVar(fCfg.WebAppDir)) fCfg.ShareRootDir = path.Clean(resolveEnvVar(fCfg.ShareRootDir)) fCfg.SThgConf.Home = path.Clean(resolveEnvVar(fCfg.SThgConf.Home)) // Config file settings overwrite default config if fCfg.WebAppDir != "" { c.WebAppDir = strings.Trim(fCfg.WebAppDir, " ") } // Is it a full path ? if !strings.HasPrefix(c.WebAppDir, "/") && exePath != "" { // Check first from current directory for _, rootD := range []string{cwd, exePath} { ff := path.Join(rootD, c.WebAppDir, "index.html") if exists(ff) { c.WebAppDir = path.Join(rootD, c.WebAppDir) break } } } if fCfg.ShareRootDir != "" { c.ShareRootDir = fCfg.ShareRootDir } if fCfg.HTTPPort != "" { c.HTTPPort = fCfg.HTTPPort } return nil } // resolveEnvVar Resolved environment variable regarding the syntax ${MYVAR} func resolveEnvVar(s string) string { re := regexp.MustCompile("\\${(.*)}") vars := re.FindAllStringSubmatch(s, -1) res := s for _, v := range vars { val := os.Getenv(v[1]) if val != "" { rer := regexp.MustCompile("\\${" + v[1] + "}") res = rer.ReplaceAllString(res, val) } } return res } // exists returns whether the given file or directory exists or not func exists(path string) bool { _, err := os.Stat(path) if err == nil { return true } if os.IsNotExist(err) { return false } return true }