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package xdsconfig
import (
"encoding/json"
"fmt"
"os"
"os/user"
"path"
"path/filepath"
"regexp"
)
type SyncThingConf struct {
BinDir string `json:"binDir"`
Home string `json:"home"`
GuiAddress string `json:"gui-address"`
GuiAPIKey string `json:"gui-apikey"`
}
type FileConfig struct {
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/agent-config.json file
// 3/ <current_dir>/agent-config.json file
// 4/ <executable dir>/agent-config.json file
func updateConfigFromFile(c *Config, confFile string) (*FileConfig, 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", "agent-config.json"))
}
cwd, err := os.Getwd()
if err == nil {
searchIn = append(searchIn, path.Join(cwd, "agent-config.json"))
}
exePath, err := filepath.Abs(filepath.Dir(os.Args[0]))
if err == nil {
searchIn = append(searchIn, path.Join(exePath, "agent-config.json"))
}
var cFile *string
for _, p := range searchIn {
if _, err := os.Stat(p); err == nil {
cFile = &p
break
}
}
fCfg := FileConfig{}
if cFile == nil {
// No config file found
return &fCfg, nil
}
c.log.Infof("Use config file: %s", *cFile)
// 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()
if err := json.NewDecoder(fd).Decode(&fCfg); err != nil {
return nil, err
}
// Support environment variables (IOW ${MY_ENV_VAR} syntax) in agent-config.json
// TODO: better to use reflect package to iterate on fields and be more generic
var rep string
if rep, err = resolveEnvVar(fCfg.SThgConf.BinDir); err != nil {
return nil, err
}
fCfg.SThgConf.BinDir = path.Clean(rep)
if rep, err = resolveEnvVar(fCfg.SThgConf.Home); err != nil {
return nil, err
}
fCfg.SThgConf.Home = path.Clean(rep)
return &fCfg, nil
}
// resolveEnvVar Resolved environment variable regarding the syntax ${MYVAR}
func resolveEnvVar(s string) (string, error) {
re := regexp.MustCompile("\\${(.*)}")
vars := re.FindAllStringSubmatch(s, -1)
res := s
for _, v := range vars {
val := os.Getenv(v[1])
if val == "" {
return res, fmt.Errorf("ERROR: %s env variable not defined", v[1])
}
rer := regexp.MustCompile("\\${" + v[1] + "}")
res = rer.ReplaceAllString(res, val)
}
return res, nil
}
// 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
}
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