- Fix .gitignore

- Note about bug with Docker driver
- Implement experimental pid ulimit of 150.

.gitignore

@@ -0,0 +1,2 @@
+play-with-docker
+

services/docker.go

@@ -29,10 +29,14 @@ func GetContainerInfo(id string) (types.ContainerJSON, error) {
 }
 
 func CreateNetwork(name string) error {
+	// TODO: This line appears to give an error when running on localhost:3000
+	// when driver is specified a name must be given.
 	opts := types.NetworkCreate{Attachable: true, Driver: "overlay"}
 	_, err := c.NetworkCreate(context.Background(), name, opts)
 
 	if err != nil {
+		log.Printf("Starting session err [%s]\n", err)
+
 		return err
 	}
 
@@ -72,7 +76,11 @@ func AttachExecConnection(execId string, ctx context.Context) (*types.HijackedRe
 
 func CreateInstance(net string) (*ptypes.Instance, error) {
 
+	var maximumPidLimit int64
+	maximumPidLimit = 150 // Set a ulimit value to prevent misuse
 	h := &container.HostConfig{NetworkMode: container.NetworkMode(net), Privileged: true}
+	h.Resources.PidsLimit = maximumPidLimit
+
 	conf := &container.Config{Image: "docker:dind"}
 	container, err := c.ContainerCreate(context.Background(), conf, h, nil, "")
 

services/session.go

@@ -18,6 +18,7 @@ func NewSession() (*types.Session, error) {
 	s := &types.Session{}
 	s.Id = uuid.NewV4().String()
 	s.Instances = map[string]*types.Instance{}
+	log.Printf("NewSession id=[%s]\n", s.Id)
 
 	//TODO: Store in something like redis
 	sessions[s.Id] = s