[RFR] Do not rebuild binaries each time

container/container.go

@@ -60,7 +60,7 @@ func (c *Container) Init() {
 	if c.Add == nil {
 		c.Add = make(map[string]string)
 	}
-	
+
 	if c.Custom == nil {
 		c.Custom = make(map[string]interface{})
 	}
@@ -213,9 +213,11 @@ func (c *Container) Start(rebuild bool) {
 }
 
 func (c *Container) BuildAndRun(currentPath string, arguments []string) {
-	buildChans := make(chan bool, 1)
-	go c.BuildOrPull(buildChans)
-	<-buildChans
+	if docker.ShouldRebuild(c.Image) {
+		buildChans := make(chan bool, 1)
+		go c.BuildOrPull(buildChans)
+		<-buildChans
+	}
 
 	c.Run(currentPath, arguments)
 }

docker/docker.go

@@ -220,6 +220,42 @@ func SnapshotProcesses() (map[string]string, error) {
 	return images, nil
 }
 
+func ShouldRebuild(imageName string) bool {
+	images, err := GetImages()
+
+	if err != nil {
+		return false
+	}
+
+	_, ok := images[imageName]
+	return !ok
+}
+
+func GetImages() (map[string]string, error) {
+	images := make(map[string]string)
+
+	imagesCommand := exec.Command(getDockerBinaryPath(), "images")
+	out, err := imagesCommand.CombinedOutput()
+	if err != nil {
+		return nil, errors.New(string(out))
+	}
+
+	// Retrieve lines & remove first and last one
+	lines := strings.Split(string(out), "\n")
+	lines = lines[1 : len(lines)-1]
+
+	for _, line := range lines {
+		fields := strings.Fields(line)
+		if fields[0] == "<none>" {
+			continue
+		}
+
+		images[fields[0]] = fields[2]
+	}
+
+	return images, nil
+}
+
 func getDockerBinaryPath() string {
 	if len(docker) != 0 {
 		return docker

gaudi/gaudi_unit_test.go

@@ -297,6 +297,7 @@ func (s *GaudiTestSuite) TestStartBinariesShouldCleanAndBuildThem(c *C) {
 
 	docker.EXPECT().ImageExists(gomock.Any()).Return(true).Times(1)
 	docker.EXPECT().HasDocker().Return(true).Times(1)
+	docker.EXPECT().ShouldRebuild(gomock.Any()).Return(true).Times(1)
 
 	util.EXPECT().PrintGreen("Building", "gaudi/npm", "...")
 	docker.EXPECT().Build(gomock.Any(), gomock.Any()).Times(1)