Query DinD instances for running containers and list the published ports

so the user can reverse proxy to the instance/port easily.

services/broadcast_info_task.go

@@ -4,5 +4,5 @@ type broadcastInfoTask struct {
 }
 
 func (c *broadcastInfoTask) Run(i *Instance) {
-	wsServer.BroadcastTo(i.session.Id, "instance stats", i.Name, i.Mem, i.Cpu, i.IsManager)
+	wsServer.BroadcastTo(i.session.Id, "instance stats", i.Name, i.Mem, i.Cpu, i.IsManager, i.Ports)
 }

services/check_used_ports_task.go

@@ -0,0 +1,10 @@
+package services
+
+type checkUsedPortsTask struct {
+}
+
+func (c checkUsedPortsTask) Run(i *Instance) {
+	if ports, err := GetUsedPorts(i); err == nil {
+		i.Ports = ports
+	}
+}

services/docker.go

@@ -46,6 +46,28 @@ func GetDaemonInfo(i *Instance) (types.Info, error) {
 	}
 	return i.dockerClient.Info(context.Background())
 }
+func GetUsedPorts(i *Instance) ([]uint16, error) {
+	if i.dockerClient == nil {
+		return nil, fmt.Errorf("Docker client for DinD (%s) is not ready", i.IP)
+	}
+	opts := types.ContainerListOptions{}
+	containers, err := i.dockerClient.ContainerList(context.Background(), opts)
+	if err != nil {
+		return nil, err
+	}
+
+	openPorts := []uint16{}
+	for _, c := range containers {
+		for _, p := range c.Ports {
+			// When port is not published on the host docker return public port as 0, so we need to avoid it
+			if p.PublicPort != 0 {
+				openPorts = append(openPorts, p.PublicPort)
+			}
+		}
+	}
+
+	return openPorts, nil
+}
 
 func CreateNetwork(name string) error {
 	opts := types.NetworkCreate{Driver: "overlay", Attachable: true}

services/instance.go

@@ -27,6 +27,7 @@ type Instance struct {
 	IsManager    *bool                   `json:"is_manager"`
 	Mem          string                  `json:"mem"`
 	Cpu          string                  `json:"cpu"`
+	Ports        []uint16                `json:"ports"`
 }
 
 func (i *Instance) IsConnected() bool {

services/task.go

@@ -7,5 +7,5 @@ type periodicTask interface {
 var periodicTasks []periodicTask
 
 func init() {
-	periodicTasks = append(periodicTasks, &collectStatsTask{}, &checkSwarmStatusTask{}, &broadcastInfoTask{})
+	periodicTasks = append(periodicTasks, &collectStatsTask{}, &checkSwarmStatusTask{}, &checkUsedPortsTask{}, &broadcastInfoTask{})
 }