Add dryad executable

Compiled dryad exposes Dryad interface with Go RPC.

Currently the only flag is path to configuration file.
It will be generated if it is not found.

Change-Id: I07809bea9991228b32f9bb24fae9c99dc1fad0c0
Signed-off-by: Aleksander Mistewicz <a.mistewicz@samsung.com>
Reviewed-on: https://mcdsrvbld02.digital.local/review/49536
Reviewed-by: Maciej Wereski <m.wereski@partner.samsung.com>
Tested-by: Maciej Wereski <m.wereski@partner.samsung.com>

diff --git a/cmd/dryad/dryad.go b/cmd/dryad/dryad.go
new file mode 100644 (file)
index 0000000..4339a5a
--- /dev/null
+++ b/cmd/dryad/dryad.go
@@ -0,0 +1,93 @@
+/*
+ *  Copyright (c) 2017-2018 Samsung Electronics Co., Ltd All Rights Reserved
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License
+ */
+
+package main
+
+import (
+       "flag"
+       "log"
+       "net"
+       "net/rpc"
+       "os"
+       "os/signal"
+
+       "git.tizen.org/tools/boruta/dryad"
+       "git.tizen.org/tools/boruta/dryad/conf"
+       dryad_rpc "git.tizen.org/tools/boruta/rpc/dryad"
+)
+
+var (
+       confPath      string
+       configuration *conf.General
+)
+
+func init() {
+       configuration = conf.NewConf()
+
+       flag.StringVar(&confPath, "conf", "/etc/boruta/dryad.conf", "path to the configuration file")
+}
+
+func exitOnErr(ctx string, err error) {
+       if err != nil {
+               log.Fatal(ctx, err)
+       }
+}
+
+func generateConfFile() {
+       f, err := os.Create(confPath)
+       exitOnErr("can't create configuration file:", err)
+       defer f.Close()
+       exitOnErr("can't generate new configuration:", configuration.Marshal(f))
+}
+
+func readConfFile() {
+       f, err := os.Open(confPath)
+       exitOnErr("can't open configuration file:", err)
+       defer f.Close()
+       exitOnErr("can't parse configuration:", configuration.Unmarshal(f))
+}
+
+func main() {
+       flag.Parse()
+
+       // Read configuration.
+       _, err := os.Stat(confPath)
+       if err != nil {
+               if os.IsNotExist(err) {
+                       generateConfFile()
+                       log.Fatal("configuration file generated. Please edit it first")
+               }
+               log.Fatal("can't access file:", err)
+       }
+       readConfFile()
+
+       rusalka := dryad.NewRusalka(configuration.User.Name, configuration.User.Groups)
+
+       l, err := net.Listen("tcp", configuration.Address)
+       exitOnErr("can't listen on port:", err)
+       defer l.Close()
+
+       srv := rpc.NewServer()
+       err = dryad_rpc.RegisterDryadService(srv, rusalka)
+       exitOnErr("can't start RPC service:", err)
+
+       go srv.Accept(l)
+
+       // Wait for interrupt.
+       c := make(chan os.Signal, 1)
+       signal.Notify(c, os.Interrupt)
+       <-c
+}