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authorSebastien Douheret <sebastien.douheret@iot.bzh>2017-05-15 11:12:21 +0200
committerSebastien Douheret <sebastien.douheret@iot.bzh>2017-05-15 19:08:31 +0200
commitbfeab33538d50ee52750de4dd4c0e72b64f674f6 (patch)
treea8ebab2a62f4ca4ccbfbe848106ca53d708c724b /lib/xdsconfig/fileconfig.go
Initial commit.
Signed-off-by: Sebastien Douheret <sebastien.douheret@iot.bzh>
Diffstat (limited to 'lib/xdsconfig/fileconfig.go')
-rw-r--r--lib/xdsconfig/fileconfig.go120
1 files changed, 120 insertions, 0 deletions
diff --git a/lib/xdsconfig/fileconfig.go b/lib/xdsconfig/fileconfig.go
new file mode 100644
index 0000000..0c4828c
--- /dev/null
+++ b/lib/xdsconfig/fileconfig.go
@@ -0,0 +1,120 @@
+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
+}