Fix Docker client port mappings by actually exposing them after binding

pkg/runtime/docker/client.go

@@ -118,19 +118,21 @@ func (dc *dockerClient) RunContainer(image string, config *runtime.ContainerConf
 	}
 
 	stopTimeout := int(config.StopTimeout)
+	bindings, exposed := portBindingsToDocker(config.PortBindings)
 
 	c, err := dc.client.ContainerCreate(context.Background(), &container.Config{
-		Hostname:    config.Hostname,
-		Tty:         true, // --tty
-		OpenStdin:   true, // --interactive
-		Cmd:         config.Cmd,
-		Image:       image,
-		Labels:      config.Labels,
-		StopTimeout: &stopTimeout,
+		Hostname:     config.Hostname,
+		ExposedPorts: exposed,
+		Tty:          true, // --tty
+		OpenStdin:    true, // --interactive
+		Cmd:          config.Cmd,
+		Image:        image,
+		Labels:       config.Labels,
+		StopTimeout:  &stopTimeout,
 	}, &container.HostConfig{
 		Binds:        binds,
 		NetworkMode:  container.NetworkMode(config.NetworkMode),
-		PortBindings: portBindingsToPortMap(config.PortBindings),
+		PortBindings: bindings,
 		AutoRemove:   config.AutoRemove,
 		CapAdd:       config.CapAdds,
 		Resources: container.Resources{

pkg/runtime/docker/port.go

@@ -8,8 +8,10 @@ import (
 	meta "github.com/weaveworks/ignite/pkg/apis/meta/v1alpha1"
 )
 
-func portBindingsToPortMap(portMappings meta.PortMappings) nat.PortMap {
-	portMap := make(nat.PortMap)
+// portBindingsToDocker takes in portMappings and returns a nat.PortMap of the
+// port bindings and a nat.PortSet of the exposed ports for the Docker client
+func portBindingsToDocker(portMappings meta.PortMappings) (nat.PortMap, nat.PortSet) {
+	bindings, exposed := make(nat.PortMap, len(portMappings)), make(nat.PortSet, len(portMappings))
 
 	for _, portMapping := range portMappings {
 		var hostIP string
@@ -23,13 +25,15 @@ func portBindingsToPortMap(portMappings meta.PortMappings) nat.PortMap {
 			protocol = meta.ProtocolTCP
 		}
 
-		portMap[nat.Port(fmt.Sprintf("%d/%s", portMapping.VMPort, protocol.String()))] = []nat.PortBinding{
+		port := nat.Port(fmt.Sprintf("%d/%s", portMapping.VMPort, protocol.String()))
+		exposed[port] = struct{}{}
+		bindings[port] = []nat.PortBinding{
 			{
 				HostIP:   hostIP,
 				HostPort: strconv.FormatUint(portMapping.HostPort, 10),
 			},
 		}
 	}
 
-	return portMap
+	return bindings, exposed
 }