load absent property from env

src/adminserver/systemcfg/systemcfg.go

@@ -227,11 +227,22 @@ func initCfgStore() (err error) {
 }
 
 // LoadFromEnv loads the configurations from allEnvs, if all is false, it just loads
-// the repeatLoadEnvs
+// the repeatLoadEnvs and the env which is absent in cfgs
 func LoadFromEnv(cfgs map[string]interface{}, all bool) error {
-	envs := repeatLoadEnvs
+	var envs map[string]interface{}
+
 	if all {
 		envs = allEnvs
+	} else {
+		envs = make(map[string]interface{})
+		for k, v := range repeatLoadEnvs {
+			envs[k] = v
+		}
+		for k, v := range allEnvs {
+			if _, exist := cfgs[k]; !exist {
+				envs[k] = v
+			}
+		}
 	}
 
 	for k, v := range envs {

src/adminserver/systemcfg/systemcfg_test.go

@@ -94,5 +94,21 @@ func TestLoadFromEnv(t *testing.T) {
 	err = LoadFromEnv(cfgs, false)
 	assert.Nil(t, err)
 	assert.Equal(t, extEndpoint, cfgs[common.ExtEndpoint])
-	assert.Equal(t, nil, cfgs[common.LDAPURL])
+	assert.Equal(t, ldapURL, cfgs[common.LDAPURL])
+
+	os.Clearenv()
+	if err := os.Setenv("LDAP_URL", ldapURL); err != nil {
+		t.Fatalf("failed to set env: %v", err)
+	}
+	if err := os.Setenv("EXT_ENDPOINT", extEndpoint); err != nil {
+		t.Fatalf("failed to set env: %v", err)
+	}
+
+	cfgs = map[string]interface{}{
+		common.LDAPURL: "ldap_url",
+	}
+	err = LoadFromEnv(cfgs, false)
+	assert.Nil(t, err)
+	assert.Equal(t, extEndpoint, cfgs[common.ExtEndpoint])
+	assert.Equal(t, "ldap_url", cfgs[common.LDAPURL])
 }