First skeleton of a simulator

backends/backends.go

@@ -15,5 +15,6 @@ func New() *engine.Engine {
 	back.Logging = false
 	// Register all backends here
 	Debug().Install(back)
+	Simulator().Install(back)
 	return back
 }

backends/simulator.go

@@ -0,0 +1,32 @@
+package backends
+
+import (
+	"github.com/dotcloud/docker/engine"
+)
+
+func Simulator() engine.Installer {
+	return &simulator{}
+}
+
+type simulator struct {
+	containers []string
+}
+
+func (s *simulator) Install(eng *engine.Engine) error {
+	eng.Register("simulator", func(job *engine.Job) engine.Status {
+		s.containers = job.Args
+		job.Eng.Register("containers", func(job *engine.Job) engine.Status {
+			t := engine.NewTable("Id", len(s.containers))
+			for _, c := range s.containers {
+				e := &engine.Env{}
+				e.Set("Id", c)
+				e.Set("Image", "foobar")
+				t.Add(e)
+			}
+			t.WriteListTo(job.Stdout)
+			return engine.StatusOK
+		})
+		return engine.StatusOK
+	})
+	return nil
+}