basic ec2 config

Docker-DCO-1.1-Signed-off-by: Aaron Feng <aaron.feng@gmail.com> (github: aaronfeng)

backends/ec2.go

@@ -3,10 +3,24 @@ package backends
 import (
   "time"
   "fmt"
+  "strings"
   "github.com/docker/libswarm/beam"
 )
 
+type ec2Config struct {
+  access_key     string
+  secret_key     string
+  security_group string
+  instance_type  string
+  keypair        string
+  region         string
+  zone           string
+  ami            string
+  tag            string
+}
+
 type ec2Client struct {
+  config *ec2Config
   Server *beam.Server
 }
 
@@ -64,12 +78,52 @@ func (c *ec2Client) attach(ctx *beam.Message) error {
   return nil
 }
 
+func newConfig(args []string) (config *ec2Config, err error) {
+  // TODO (aaron): fail fast on incorrect number of args
+
+  var optValPair []string
+  var opt, val string
+
+  config = new(ec2Config)
+  for _, value := range args {
+    optValPair = strings.Split(value, "=")
+    opt = optValPair[0]
+    val = optValPair[1]
+
+    switch opt {
+      case "--region":
+        config.region = val
+      case "--zone":
+        config.zone = val
+      case "--tag":
+        config.tag = val
+      case "--ami":
+        config.ami = val
+      case "--keypair":
+        config.keypair = val
+      case "--security_group":
+        config.security_group = val
+      case "--instance_type":
+        config.instance_type = val
+      default:
+        fmt.Printf("Unrecognizable option: %s value: %s", opt, val)
+    }
+  }
+  return config, nil
+}
 
 func Ec2() beam.Sender {
   backend := beam.NewServer()
   backend.OnSpawn(beam.Handler(func(ctx *beam.Message) error {
     fmt.Println("*** init ***")
-    client := &ec2Client{beam.NewServer()}
+
+    var config, err = newConfig(ctx.Args)
+
+    if (err != nil) {
+      return err
+    }
+
+    client := &ec2Client{config, beam.NewServer()}
     client.Server.OnSpawn(beam.Handler(client.spawn))
     client.Server.OnStart(beam.Handler(client.start))
     client.Server.OnStop(beam.Handler(client.stop))
@@ -78,7 +132,7 @@ func Ec2() beam.Sender {
     client.Server.OnError(beam.Handler(client.error))
     client.Server.OnLs(beam.Handler(client.ls))
     client.Server.OnGet(beam.Handler(client.get))
-    _, err := ctx.Ret.Send(&beam.Message{Verb: beam.Ack, Ret: client.Server})
+    _, err = ctx.Ret.Send(&beam.Message{Verb: beam.Ack, Ret: client.Server})
     return err
   }))
   return backend