Adding tag with stage name (#9)

* Encapsulate variables as good practice

* Added stage tag and push

buildspec.yml

@@ -4,19 +4,21 @@ version: 0.2
 phases:
   pre_build:
     commands:
-      - echo Logging in to Amazon ECR...
-      - $(aws ecr get-login --region $AWS_REGION)
+      - echo "Logging in to Amazon ECR..."
+      - $(aws ecr get-login --region ${AWS_REGION})
   build:
     commands:
-      - echo Build started on `date`
-      - echo Building the Docker image...
-      - docker build -t $IMAGE_REPO_NAME .
-      - docker tag $IMAGE_REPO_NAME:$IMAGE_TAG $AWS_ACCOUNT_ID.dkr.ecr.$AWS_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG
+      - echo "Build started on $(date)"
+      - echo "Building the Docker image..."
+      - docker build --tag ${IMAGE_REPO_NAME} .
+      - docker tag ${IMAGE_REPO_NAME}:${IMAGE_TAG} ${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_REGION}.amazonaws.com/${IMAGE_REPO_NAME}:${IMAGE_TAG}
+      - docker tag ${IMAGE_REPO_NAME}:${IMAGE_TAG} ${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_REGION}.amazonaws.com/${IMAGE_REPO_NAME}:${STAGE}
   post_build:
     commands:
-      - echo Build completed on `date`
-      - echo Pushing the Docker image to ECR...
-      - docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG
+      - echo "Build completed on $(date)"
+      - echo "Pushing the Docker image to ECR..."
+      - docker push ${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_REGION}.amazonaws.com/${IMAGE_REPO_NAME}:${IMAGE_TAG}
+      - docker push ${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_REGION}.amazonaws.com/${IMAGE_REPO_NAME}:${STAGE}      
       - envsubst < "Dockerrun.aws.json.template" > "Dockerrun.aws.json"
 artifacts:
   files: