CloudFormation Template - Setting Container Image by Parameter Selection

Question

Looking to set a specified container image based on the selection of a parameter; say if the selection is "aceptance" the container image would point to the acceptance branch image, or "deploy" would point to deploy, etc..

Here is one attempt I have tried, but not sure if this is the best or allowed path. Upon Creating the Stack I receive an error:

ECSTaskDefinition CREATE_FAILED Invalid request provided: Create TaskDefinition: Container.name should not be null or empty. (Service: AmazonECS; Status Code: 400; Error Code: ClientException; Request ID: b679c7be-ad3e-4791-b388-d2cb87332b94; Proxy: null)

Parameters:
    Branch:
    Type: String
    AllowedValues:
        - acceptance
        - canary
        - deploy
Mappings:
BranchSelection:
    acceptance:
        BranchType: "${AWS::AccountId}.dkr.ecr.${AWS::Region}.amazonaws.com/acceptance"
    canary:
        BranchType: "${AWS::AccountId}.dkr.ecr.${AWS::Region}.amazonaws.com/canary"
    deploy:
        BranchType: "${AWS::AccountId}.dkr.ecr.${AWS::Region}.amazonaws.com/deploy"

ECSTaskDefinition:
        Type: "AWS::ECS::TaskDefinition"
        Properties:
            ContainerDefinitions: 
              - 
                Environment: 
                  - 
                    Name: "ACCESS_KEY_ID"
                    Value:
                        !Sub
                            - "{{resolve:ssm:/doorways/${STAGE}/ACCESS_KEY_ID:1}}"
                            - { STAGE: !Ref STAGE }
                  - 
                    Name: "SECRET_ACCESS_KEY"
                    Value:
                        !Sub
                            - "{{resolve:ssm:/doorways/${STAGE}/AWS_SECRET_KEY:1}}"
                            - { STAGE: !Ref STAGE }                  
                  - 
                    Name: "SENDGRID_USERNAME"
                    Value:
                        !Sub
                            - "{{resolve:ssm:/doorways/${STAGE}/SENDGRID_USERNAME:1}}"
                            - { STAGE: !Ref STAGE }
                  - 
                    Name: "SENDGRID_PASSWORD"
                    Value:
                        !Sub
                            - "{{resolve:ssm:/doorways/${STAGE}/SENDGRID_PASSWORD:1}}"
                            - { STAGE: !Ref STAGE }
                  - 
                    Name: "REGION"
                    Value: !Ref AWS::Region                  
              -
                Essential: true                 
                Image: !FindInMap
                  - BranchSelection
                  - !Ref Branch
                  - BranchType
                LogConfiguration: 
                    LogDriver: "awslogs"
                    Options: 
                        awslogs-group: "/ecs/doorways-task-definition"
                        awslogs-region: !Ref AWS::Region
                        awslogs-stream-prefix: "ecs"
                Name:
                    !Sub
                        - 'dw-${FriendlyName}-${SiteId}-${STAGE}'
                        - { FriendlyName: !Ref FriendlyName, SiteId: !Ref SiteId, STAGE: !Ref STAGE }
                PortMappings: 
                  - 
                    ContainerPort: 3000
                    HostPort: 3000
                    Protocol: "tcp"
              - 

Has anyone had a similar use case, and could possibly point me in the right direction?

Answer 1

Environment must have at least one:

  Name: String
  Value: String

You don't have any. Also your FindInMap will not work they way you think it will. The values ${AWS::AccountId} and ${AWS::Region} will not be substituted and you will end up with literal strings.