Detect undefined env variables used in config.json

Signed-off-by: Sebastien Douheret <sebastien.douheret@iot.bzh>

diff --git a/lib/xdsconfig/fileconfig.go b/lib/xdsconfig/fileconfig.go
index 262d023..ed3e82d 100644 (file)
--- a/lib/xdsconfig/fileconfig.go
+++ b/lib/xdsconfig/fileconfig.go
@@ -2,6 +2,7 @@ package xdsconfig
 
 import (
        "encoding/json"
+       "fmt"
        "os"
        "os/user"
        "path"
@@ -59,6 +60,8 @@ func updateConfigFromFile(c *Config, confFile string) error {
                return 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
@@ -73,9 +76,21 @@ func updateConfigFromFile(c *Config, confFile string) error {
 
        // 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))
+       var rep string
+       if rep, err = resolveEnvVar(fCfg.WebAppDir); err != nil {
+               return err
+       }
+       fCfg.WebAppDir = path.Clean(rep)
+
+       if rep, err = resolveEnvVar(fCfg.ShareRootDir); err != nil {
+               return err
+       }
+       fCfg.ShareRootDir = path.Clean(rep)
+
+       if rep, err = resolveEnvVar(fCfg.SThgConf.Home); err != nil {
+               return err
+       }
+       fCfg.SThgConf.Home = path.Clean(rep)
 
        // Config file settings overwrite default config
 
@@ -106,18 +121,21 @@ func updateConfigFromFile(c *Config, confFile string) error {
 }
 
 // resolveEnvVar Resolved environment variable regarding the syntax ${MYVAR}
-func resolveEnvVar(s string) string {
+func resolveEnvVar(s string) (string, error) {
        re := regexp.MustCompile("\\${(.*)}")
        vars := re.FindAllStringSubmatch(s, -1)
        res := s
        for _, v := range vars {
                val := os.Getenv(v[1])
-               if val != "" {
-                       rer := regexp.MustCompile("\\${" + v[1] + "}")
-                       res = rer.ReplaceAllString(res, val)
+               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
+
+       return res, nil
 }
 
 // exists returns whether the given file or directory exists or not