Adds "--image_tags" flag to have better control over (#24)

container definition image tags rewrites.

Fixes #23

Author: ekini

cmd/deploy.go

@@ -41,6 +41,7 @@ If deployment failed, then rolls back to the previous stack definition.`,
 			viper.GetString("profile"),
 			viper.GetString("cluster"),
 			viper.GetString("image_tag"),
+			viper.GetStringSlice("image_tags"),
 			viper.GetStringSlice("deploy.services"),
 		)
 		if err != nil {

cmd/root.go

@@ -48,11 +48,13 @@ func init() {
 	rootCmd.PersistentFlags().BoolVarP(&debug, "debug", "d", false, "Show debug output")
 	rootCmd.PersistentFlags().StringP("cluster", "c", "", "name of cluster (required)")
 	rootCmd.PersistentFlags().StringP("profile", "p", "", "name of AWS profile to use, which is set in ~/.aws/config")
-	rootCmd.PersistentFlags().StringP("image_tag", "", "", "Overrides the docker image tag")
+	rootCmd.PersistentFlags().StringP("image_tag", "", "", "Overrides the docker image tag in all container definitions. Overrides \"--image-tags\" flag.")
+	rootCmd.PersistentFlags().StringSliceP("image_tags", "", []string{}, "Modifies the docker image tags in container definitions. Can be specified several times, one for each container definition. Also takes comma-separated values in one tag. I.e. if there are 2 containers and --image-tags is set once to \"new\", then the image tag of the first container will be modified, leaving the second one untouched. Gets overridden by  \"--image-tag\". If you have 3 container definitions and want to modify tags for the 1st and the 3rd, but leave the 2nd unchanged, specify it as \"--image_tags first_tag,,last_tag\".")
 
 	viper.BindPFlag("profile", rootCmd.PersistentFlags().Lookup("profile"))
 	viper.BindPFlag("cluster", rootCmd.PersistentFlags().Lookup("cluster"))
 	viper.BindPFlag("image_tag", rootCmd.PersistentFlags().Lookup("image_tag"))
+	viper.BindPFlag("image_tags", rootCmd.PersistentFlags().Lookup("image_tags"))
 
 }
 

cmd/run.go

@@ -34,6 +34,7 @@ It can modify the container command.
 			viper.GetString("run.service"),
 			viper.GetString("task_definition"),
 			viper.GetString("image_tag"),
+			viper.GetStringSlice("image_tags"),
 			containerName,
 			viper.GetString("log_group"),
 			viper.GetString("run.launch_type"),

lib/deploy.go

@@ -2,7 +2,6 @@ package lib
 
 import (
 	"fmt"
-	"strings"
 	"sync"
 	"time"
 
@@ -12,7 +11,7 @@ import (
 )
 
 // DeployServices deploys specified services in parallel
-func DeployServices(profile, cluster, imageTag string, services []string) (exitCode int, err error) {
+func DeployServices(profile, cluster, imageTag string, imageTags, services []string) (exitCode int, err error) {
 	ctx := log.WithFields(log.Fields{
 		"cluster":   cluster,
 		"image_tag": imageTag,
@@ -31,7 +30,7 @@ func DeployServices(profile, cluster, imageTag string, services []string) (exitC
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			deployService(ctx, cluster, imageTag, service, exits, rollback, &wg)
+			deployService(ctx, cluster, imageTag, imageTags, service, exits, rollback, &wg)
 		}()
 	}
 
@@ -53,7 +52,7 @@ func DeployServices(profile, cluster, imageTag string, services []string) (exitC
 	return
 }
 
-func deployService(ctx log.Interface, cluster, imageTag string, service string, exitChan chan int, rollback chan bool, wg *sync.WaitGroup) {
+func deployService(ctx log.Interface, cluster, imageTag string, imageTags []string, service string, exitChan chan int, rollback chan bool, wg *sync.WaitGroup) {
 	ctx = ctx.WithFields(log.Fields{
 		"service": service,
 	})
@@ -91,22 +90,9 @@ func deployService(ctx log.Interface, cluster, imageTag string, service string,
 
 	taskDefinition := describeTaskResult.TaskDefinition
 	// replace the image tag if there is any
-	for n, containerDefinition := range taskDefinition.ContainerDefinitions {
-		if imageTag != "" {
-			imageWithTag := strings.SplitN(aws.StringValue(containerDefinition.Image), ":", 2)
-			if len(imageWithTag) == 2 { // successfully split into 2 parts: repo and tag
-				image := strings.Join([]string{
-					imageWithTag[0],
-					imageTag,
-				}, ":")
-				taskDefinition.ContainerDefinitions[n].Image = aws.String(image)
-				ctx.WithFields(log.Fields{
-					"container_name": aws.StringValue(containerDefinition.Name),
-					"image":          image,
-					"old_image_tag":  imageWithTag[1],
-				}).Info("Image tag changed")
-			}
-		}
+	if err := modifyContainerDefinitionImages(imageTag, imageTags, taskDefinition.ContainerDefinitions, ctx); err != nil {
+		ctx.WithError(err).Error("Can't modify container definition images")
+		exitChan <- 1
 	}
 
 	// now, register the new task

lib/run.go

@@ -2,15 +2,14 @@ package lib
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/apex/log"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/ecs"
 )
 
 // RunTask runs the specified one-off task in the cluster using the task definition
-func RunTask(profile, cluster, service, taskDefinitionName, imageTag, containerName, awslogGroup, launchType string, args []string) (exitCode int, err error) {
+func RunTask(profile, cluster, service, taskDefinitionName, imageTag string, imageTags []string, containerName, awslogGroup, launchType string, args []string) (exitCode int, err error) {
 	err = makeSession(profile)
 	if err != nil {
 		return 1, err
@@ -27,23 +26,12 @@ func RunTask(profile, cluster, service, taskDefinitionName, imageTag, containerN
 		return 1, err
 	}
 	taskDefinition := describeResult.TaskDefinition
-	//var containerNumber int
+
 	var foundContainerName bool
+	if err := modifyContainerDefinitionImages(imageTag, imageTags, taskDefinition.ContainerDefinitions, ctx); err != nil {
+		return 1, err
+	}
 	for n, containerDefinition := range taskDefinition.ContainerDefinitions {
-		if imageTag != "" {
-			imageWithTag := strings.SplitN(aws.StringValue(containerDefinition.Image), ":", 2)
-			if len(imageWithTag) == 2 { // successfully split into 2 parts: repo and tag
-				image := strings.Join([]string{
-					imageWithTag[0],
-					imageTag,
-				}, ":")
-				taskDefinition.ContainerDefinitions[n].Image = aws.String(image)
-				ctx.WithFields(log.Fields{
-					"container_name": aws.StringValue(containerDefinition.Name),
-					"image":          image,
-				}).Debug("Image tag changed")
-			}
-		}
 		if aws.StringValue(containerDefinition.Name) == containerName {
 			foundContainerName = true
 			taskDefinition.ContainerDefinitions[n].Command = aws.StringSlice(args)

lib/util.go

@@ -9,6 +9,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/arn"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/cloudwatchlogs"
+	"github.com/aws/aws-sdk-go/service/ecs"
 )
 
 var localSession *session.Session
@@ -92,3 +93,38 @@ func fetchCloudWatchLog(cluster, containerName, awslogGroup, taskUUID string, de
 	}()
 	return printCloudWatchLogs(awslogGroup, streamName)
 }
+
+func modifyContainerDefinitionImages(imageTag string, imageTags []string, containerDefinitions []*ecs.ContainerDefinition, ctx log.Interface) error {
+
+	for n, containerDefinition := range containerDefinitions {
+		ctx := ctx.WithField("container_name", aws.StringValue(containerDefinition.Name))
+		imageWithTag := strings.SplitN(aws.StringValue(containerDefinition.Image), ":", 2)
+
+		if len(imageWithTag) == 2 { // successfully split into 2 parts: repo and tag
+			var newTag string // if set we'll change the definition
+			if imageTag != "" {
+				newTag = imageTag // this takes precedence
+			} else if len(imageTags) > n && imageTags[n] != "" { // the expression below will make this obsolete, as if the tag is "", then it won't be used anyway. But just adding this condition here to be explicit, just in case we want to do something in here later.
+				newTag = imageTags[n]
+			}
+
+			if newTag != "" {
+				image := strings.Join([]string{
+					imageWithTag[0],
+					newTag,
+				}, ":")
+				containerDefinitions[n].Image = aws.String(image)
+				ctx.WithFields(log.Fields{
+					"image":   image,
+					"new_tag": newTag,
+					"old_tag": imageWithTag[1],
+				}).Debug("Image tag changed")
+			}
+
+		} else {
+			ctx.Debug("Container doesn't seem to have a tag in the image. It's safer to not do anything.")
+		}
+
+	}
+	return nil
+}