Added support for getting tag name from environment variable

README.md

@@ -16,9 +16,17 @@ Usage
 
     Optional arguments:
         -t | --timeout          Default is 90s. Script monitors ECS Service for new task definition to be running.
+        -e | --tag-env-var      Get image tag name from environment variable. If provided this will override value specified in image name argument.
+        -v | --verbose          Verbose output
 
-    Example:
-        ecs-deploy -k ABC123 -s SECRETKEY -c production1 -n doorman-service -i docker.repo.com/doorman:latest
+    Examples:
+      Simple (Using env vars for AWS settings):
+
+        ecs-deploy -c production1 -n doorman-service -i docker.repo.com/doorman:latest
+
+      All options:
+
+        ecs-deploy -k ABC123 -s SECRETKEY -r us-east-1 -c production1 -n doorman-service -i docker.repo.com/doorman -t 240 -e CI_TIMESTAMP -v
 
 How it works
 ------------
@@ -72,19 +80,36 @@ be an unlikely use case._
 This behavior allows two possible process to specify which images, and therefore which configurations, to deploy. First, you
 may set the tag to always be `latest` (or some other static value), like so:
 
-    ecs-deploy XXXXX XXXXX us-east-1 default my_task_def my_app my.private.repo.com/frontend_container:lastest
+    ecs-deploy -c CLUSTERNAME -n SERVICENAME -i my.private.repo.com/frontend_container:lastest
 
 This will result in identical new versions of the Task Definition being created, but the Service will still do a blue/green
 deployment, and will so will pull down the latest version (if you previously pushed it into the registry).
 
 Alternatively, you may specify some other means of obtaining the tag, since the script `eval`s the image string. You could use
 git tags as a map to docker tags:
 
-    ecs-deploy XXXXX XXXXX us-east-1 default my_task_def my_app 'my.private.repo.com/frontend_container:`git describe`'
+    ecs-deploy -c CLUSTERNAME -n SERVICENAME -i 'my.private.repo.com/frontend_container:`git describe`'
 
 Or perhaps just obtain read the docker tag from another file in your development:
 
-    ecs-deploy XXXXX XXXXX us-east-1 default my_task_def my_app 'my.private.repo.com/frontend_container:$(< VERSION)'
+    ecs-deploy -c CLUSTERNAME -n SERVICENAME -i 'my.private.repo.com/frontend_container:$(< VERSION)'
 
 In any case, just make sure your process builds, tags, and pushes the docker image you use to the repository before running
 this script.
+
+Use Environment Variable for tag name value
+-------------------------------------------
+In some cases you may want to use an environment variable for the tag name of your image.
+For instance, we use Codeship for continous integration and deployment. In their Docker
+environment they can build images and tag them with different variables, such as
+the current unix timestamp. We want to use these unique and changing values for image tags
+so that each task definition refers to a unique docker image/tag. This gives us the
+ability to revert/rollback changes by just selecting a previous task definition and
+updating the service. We plan to add a revert command/option to ecs-deploy to simplify this further.
+
+Using the ```-e``` argument you can provide the name of an environment variable that
+holds the value you wish to use for the tag. On Codeship they set an env var named CI_TIMESTAMP.
+
+So we use ```ecs-deploy``` like this:
+
+    ecs-deploy -c production1 -n doorman-api -i my.private.repo/doorman-api -e CI_TIMESTAMP

ecs-deploy

@@ -17,9 +17,17 @@ function usage() {
 
     Optional arguments:
         -t | --timeout          Default is 90s. Script monitors ECS Service for new task definition to be running.
+        -e | --tag-env-var      Get image tag name from environment variable. If provided this will override value specified in image name argument.
+        -v | --verbose          Verbose output
 
-    Example:
-        ecs-deploy -k ABC123 -s SECRETKEY -c production1 -n doorman-service -i docker.repo.com/doorman:latest
+    Examples:
+      Simple (Using env vars for AWS settings):
+
+        ecs-deploy -c production1 -n doorman-service -i docker.repo.com/doorman:latest
+
+      All options:
+
+        ecs-deploy -k ABC123 -s SECRETKEY -r us-east-1 -c production1 -n doorman-service -i docker.repo.com/doorman -t 240 -e CI_TIMESTAMP -v
 
 EOM
 
@@ -34,8 +42,9 @@ SERVICE=false
 IMAGE=false
 TIMEOUT=90
 VERBOSE=false
+TAGVAR=false
 
-# AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY can be set as environment variables 
+# AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY can be set as environment variables
 if [ -z ${AWS_ACCESS_KEY_ID+x} ]; then AWS_ACCESS_KEY_ID=false; fi
 if [ -z ${AWS_SECRET_ACCESS_KEY+x} ]; then AWS_SECRET_ACCESS_KEY=false; fi
 
@@ -69,6 +78,10 @@ do
             TIMEOUT="$2"
             shift
             ;;
+        -e|--tag-env-var)
+            TAGVAR="$2"
+            shift
+            ;;
         -v|--verbose)
             VERBOSE=true
             ;;
@@ -85,23 +98,23 @@ if [ $VERBOSE == true ]; then
 fi
 
 # Make sure we have all the variables needed: AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, CLUSTER, SERVICE, IMAGE
-if [ $AWS_ACCESS_KEY_ID == false ]; then 
+if [ $AWS_ACCESS_KEY_ID == false ]; then
     echo "AWS_ACCESS_KEY_ID is required. You can set it as an environment variable or pass the value using -k or --aws-access-key"
     exit 1
 fi
-if [ $AWS_SECRET_ACCESS_KEY == false ]; then 
+if [ $AWS_SECRET_ACCESS_KEY == false ]; then
     echo "AWS_SECRET_ACCESS_KEY is required. You can set it as an environment variable or pass the value using -s or --aws-secret-key"
     exit 1
 fi
-if [ $CLUSTER == false ]; then 
+if [ $CLUSTER == false ]; then
     echo "CLUSTER is required. You can pass the value using -c or --cluster"
     exit 1
 fi
-if [ $SERVICE == false ]; then 
+if [ $SERVICE == false ]; then
     echo "SERVICE is required. You can pass the value using -n or --service-name"
     exit 1
 fi
-if [ $IMAGE == false ]; then 
+if [ $IMAGE == false ]; then
     echo "IMAGE is required. You can pass the value using -i or --image"
     exit 1
 fi
@@ -115,13 +128,30 @@ aws ecs describe-task-definition --task-def $TASK_DEFINITION > def
 
 # Extract the image from its tag
 if [[ $IMAGE =~ ^[^:]+:[^:/]+$ ]]; then
+  # Image with format registry/repo:tag
   im=`echo $IMAGE | cut -d':' -f 1`
   tag=`echo $IMAGE | cut -d':' -f 2`
+elif [[ $IMAGE =~ ^[^:]+/[^:]+$ ]]; then
+  # Image with format registry/repo (no tag specified)
+  im=`echo $IMAGE | cut -d':' -f 1`
 elif [[ $IMAGE =~ ^[^:]+:[^:]+:[^:]+$ ]]; then
+  # Image with format registry:port/repo:tag
   im=`echo $IMAGE | cut -d':' -f 1,2`
   tag=`echo $IMAGE | cut -d':' -f 3`
+elif [[ $IMAGE =~ ^[^:/]+:[^:]+/[^:]+$ ]]; then
+  # Image with format registry:port/repo (no tag specified)
+  im=`echo $IMAGE | cut -d':' -f 1,2`
 else
-  echo "You must specify an image with a tag" && exit 1;
+  echo "Unable to parse image name: $IMAGE, check the format and try again" && exit 1
+fi
+
+# Tag was not found in image name
+if [[ -n $tag ]]; then
+  # Get tag name value from ENV var
+  tag=${!TAGVAR}
+  if [[ "x$tag" == "x" ]]; then
+    echo "The ENV var named $TAGNAME is empty or not set" && exit 1;
+  fi
 fi
 
 # Extract out the registry (and possibly repository) from the image, if applicable
@@ -163,30 +193,29 @@ UPDATE=`aws ecs update-service --cluster $CLUSTER --service $SERVICE --task-defi
 # See if the service is able to come up again
 every=10
 i=0
-while [ $i -lt $TIMEOUT ] 
+while [ $i -lt $TIMEOUT ]
 do
   # Scan the list of running tasks for that service, and see if one of them is the
   # new version of the task definition
   rm -f tasks
-  
+
   aws ecs list-tasks --cluster $CLUSTER  --service-name $SERVICE --desired-status RUNNING \
     | jq '.taskArns[]' \
     | xargs -I{} aws ecs describe-tasks --cluster $CLUSTER --tasks {} >> tasks
-  
+
   jq < tasks > results ".tasks[]| if .taskDefinitionArn == \"$NEW_TASKDEF\" then . else empty end|.lastStatus"
-  
+
   RUNNING=`grep -e "RUNNING" results`
 
   if [ $RUNNING ]; then
     echo "Service updated successfully, new task definition running.";
     exit 0
   fi
-  
+
   sleep $every
   i=$(( $i + $every ))
 done
 
 # Timeout
 echo "ERROR: New task definition not running within $TIMEOUT seconds"
 exit 1
-