Show note in console when image is being pulled, show pull status to admins

environment/docker/container.go

@@ -3,6 +3,7 @@ package docker
 import (
 	"bufio"
 	"context"
+	"encoding/json"
 	"fmt"
 	"github.com/apex/log"
 	"github.com/docker/docker/api/types"
@@ -19,6 +20,11 @@ import (
 	"time"
 )
 
+type imagePullStatus struct {
+	Status   string `json:"status"`
+	Progress string `json:"progress"`
+}
+
 // Attaches to the docker container itself and ensures that we can pipe data in and out
 // of the process stream. This should not be used for reading console data as you *will*
 // miss important output at the beginning because of the time delay with attaching to the
@@ -307,6 +313,9 @@ func (e *Environment) followOutput() error {
 //
 // TODO: local images
 func (e *Environment) ensureImageExists(image string) error {
+	e.Events().Publish(environment.DockerImagePullStarted, "")
+	defer e.Events().Publish(environment.DockerImagePullCompleted, "")
+
 	// Give it up to 15 minutes to pull the image. I think this should cover 99.8% of cases where an
 	// image pull might fail. I can't imagine it will ever take more than 15 minutes to fully pull
 	// an image. Let me know when I am inevitably wrong here...
@@ -374,12 +383,18 @@ func (e *Environment) ensureImageExists(image string) error {
 	// is done being pulled, which is what we need.
 	scanner := bufio.NewScanner(out)
 	for scanner.Scan() {
-		continue
+		s := imagePullStatus{}
+		fmt.Println(scanner.Text())
+		if err := json.Unmarshal(scanner.Bytes(), &s); err == nil {
+			e.Events().Publish(environment.DockerImagePullStatus, s.Status+" "+s.Progress)
+		}
 	}
 
 	if err := scanner.Err(); err != nil {
 		return err
 	}
 
+	log.WithField("image", image).Debug("completed docker image pull")
+
 	return nil
 }

environment/environment.go

@@ -9,6 +9,9 @@ const (
 	ConsoleOutputEvent       = "console output"
 	StateChangeEvent         = "state change"
 	ResourceEvent            = "resources"
+	DockerImagePullStarted   = "docker image pull started"
+	DockerImagePullStatus    = "docker image pull status"
+	DockerImagePullCompleted = "docker image pull completed"
 )
 
 const (

server/listeners.go

@@ -11,6 +11,12 @@ import (
 	"strconv"
 )
 
+var dockerEvents = []string{
+	environment.DockerImagePullStatus,
+	environment.DockerImagePullStarted,
+	environment.DockerImagePullCompleted,
+}
+
 // Adds all of the internal event listeners we want to use for a server. These listeners can only be
 // removed by deleting the server as they should last for the duration of the process' lifetime.
 func (s *Server) StartEventListeners() {
@@ -45,10 +51,23 @@ func (s *Server) StartEventListeners() {
 		s.emitProcUsage()
 	}
 
+	docker := func(e events.Event) {
+		if e.Topic == environment.DockerImagePullStatus {
+			s.Events().Publish(InstallOutputEvent, e.Data)
+		} else if e.Topic == environment.DockerImagePullStarted {
+			s.PublishConsoleOutputFromDaemon("Pulling Docker container image, this could take a few minutes to complete...")
+		} else {
+			s.PublishConsoleOutputFromDaemon("Finished pulling Docker container image")
+		}
+	}
+
 	s.Log().Info("registering event listeners: console, state, resources...")
 	s.Environment.Events().On(environment.ConsoleOutputEvent, &console)
 	s.Environment.Events().On(environment.StateChangeEvent, &state)
 	s.Environment.Events().On(environment.ResourceEvent, &stats)
+	for _, evt := range dockerEvents {
+		s.Environment.Events().On(evt, &docker)
+	}
 }
 
 var stripAnsiRegex = regexp.MustCompile("[\u001B\u009B][[\\]()#;?]*(?:(?:(?:[a-zA-Z\\d]*(?:;[a-zA-Z\\d]*)*)?\u0007)|(?:(?:\\d{1,4}(?:;\\d{0,4})*)?[\\dA-PRZcf-ntqry=><~]))")