Use other CloudFormation stack outputs as env variables in my ECS tasks

[asungomez]

Amplify CLI Version

12.7.1

Question

Hi all!

I've created an API as a serverless container in Fargate using the Amplify CLI. All is good and works. Then I want to set up a DocumentDB for data storage (I need Mongo compatibility, cannot do the default DynamoDB). I've created a custom resource with the stack that creates my cluster, my instances, and a secret in the Secrets Manager with the credentials. The stack outputs are the Cluster endpoint, Cluster port, and Secret ARN.

I would like to inject these 3 values into my Fargate container as environment variables. Here's what I've tried so far:

• Adding them as parameters to the API CF stack: not sure if it's possible. Can't do it through the CLI using the "Access other resources" option, and do not want to do it through the team-provider file because that would mean hardcoding the values, and that's not what I want.
• Adding the Cluster, Instance, and Secret to the API stack as extra resources, so I can reference them directly. They get deleted every time I amplify push (I assume the stack gets regenerated from the docker-compose and overrides any changes I make).

Is there anything else I can try?

Edit: I've managed to inject the parameters into the stack by adding them to the backend-config.json and to the amplify-meta.json, into the dependsOn array, like this:

  "MyAPI": {
      "apiType": "REST",
      "build": true,
      "dependsOn": [
        {
          "attributes": [
            "ClusterName",
            "VpcId",
            "VpcCidrBlock",
            "SubnetIds",
            "VpcLinkId",
            "CloudMapNamespaceId"
          ],
          "category": "",
          "resourceName": "NetworkStack"
        },
        {
          "attributes": [
            "ClusterEndpoint",
            "ClusterPort",
            "PasswordSecretArn"
          ],
          "category": "",
          "resourceName": "customDatabase"
        }
      ],
      "deploymentMechanism": "FULLY_MANAGED",
      "iamAccessUnavailable": true,
      "imageSource": {
        "type": "CUSTOM"
      },
      "providerPlugin": "awscloudformation",
      "resourceName": "graphql",
      "restrictAccess": false,
      "service": "ElasticContainer",
      "skipHashing": false
    }

Now I have them in the CF stack:

    "customDatabaseClusterEndpoint": {
      "Type": "String"
    },
    "customDatabaseClusterPort": {
      "Type": "String"
    },
    "customDatabasePasswordSecretArn": {
      "Type": "String"
    },

But every time I try to reference them from the container definition:

        "ContainerDefinitions": [
          {
            "Command": [],
            "EntryPoint": [],
            "Environment": [
              {
                "Name": "DB_ENDPOINT",
                "Value": {
                  "Ref": "customDatabaseClusterEndpoint"
                }
              }
            ],

It gets overriden by the amplify push command

[ykethan]

Hey @asungomez, thank you for reaching out. The issue appears to be similar to feature request #7049. Utilizing custom resource outputs into a different resource such as API is currently not supported.
Closing the issue as duplicate, please feel free in adding a thumbs up to the feature request.

[github-actions]

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