Add containers monitoring when opening UI

Signed-off-by: Lou Marvin Caraig <loumarvincaraig@gmail.com>

cmd/sourced/cmd/web.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"regexp"
 	"runtime"
 	"strings"
 	"time"
@@ -15,6 +16,7 @@ import (
 	"github.com/src-d/sourced-ce/cmd/sourced/compose"
 	"github.com/src-d/sourced-ce/cmd/sourced/compose/workdir"
 	"github.com/src-d/sourced-ce/cmd/sourced/dir"
+	"github.com/src-d/sourced-ce/cmd/sourced/docker"
 )
 
 // The service name used in docker-compose.yml for the srcd/sourced-ui image
@@ -78,6 +80,67 @@ func waitForContainer(stdout *bytes.Buffer) {
 	}
 }
 
+var newLineFormatter = regexp.MustCompile(`(\r\n|\r|\n)`)
+
+func normalizeNewLine(s string) string {
+	return newLineFormatter.ReplaceAllString(s, "\n")
+}
+
+func runMonitor(ch chan<- error) {
+	go func() {
+		client, err := docker.GetClient()
+		if err != nil {
+			ch <- errors.Wrap(err, "cannot get docker client")
+			return
+		}
+
+		var stdout bytes.Buffer
+		if err := compose.RunWithIO(context.Background(),
+			os.Stdin, &stdout, nil, "ps", "-q"); err != nil {
+			ch <- errors.Wrap(err, "cannot get services' container id")
+			return
+		}
+
+		containerIds := strings.Split(
+			normalizeNewLine(strings.TrimSpace(stdout.String())),
+			"\n",
+		)
+
+		for {
+			for _, contID := range containerIds {
+				cont, err := docker.InfoWithClient(client, contID)
+				if err != nil {
+					ch <- errors.Wrapf(err, "unable to get info for container with id '%s'", contID)
+					return
+				}
+
+				service := cont.Labels["com.docker.compose.service"]
+
+				if cont.State == "exited" {
+					if service != "ghsync" && service != "gitcollector" {
+						ch <- fmt.Errorf("service '%s' is in state '%s'", service, cont.State)
+						return
+					}
+
+					if !strings.HasPrefix(cont.Status, "Exited (0)") {
+						ch <- fmt.Errorf("service '%s' exited with status: %s", service, cont.Status)
+						return
+					}
+
+					continue
+				}
+
+				if cont.State != "created" && cont.State != "running" {
+					ch <- fmt.Errorf("service '%s' is in state '%s'", service, cont.State)
+					return
+				}
+			}
+
+			time.Sleep(1 * time.Second)
+		}
+	}()
+}
+
 // OpenUI opens the browser with the UI.
 func OpenUI(timeout time.Duration) error {
 	var stdout bytes.Buffer
@@ -89,6 +152,8 @@ func OpenUI(timeout time.Duration) error {
 	ch := make(chan error)
 	containerReady := err == nil
 
+	runMonitor(ch)
+
 	go func() {
 		if !containerReady {
 			waitForContainer(&stdout)