[Feature] Inject the GraphQL API Id Output to all the Lambdas

Is your feature request related to a problem? Please describe. The GraphQL API Id is used to generate the DynamoDB table’s name, is also used to generate the export name of some outputs of other stacks, for example, the StreamArn of a table. I’ve seen a few comments asking how to get the API Id from a Lambda like this one https://github.com/aws-amplify/amplify-cli/issues/1002#issuecomment-474714854 Additionally, the export name of the GraphQL API Id Output is so random that it can not be referenced easily, see this comments https://github.com/aws-amplify/amplify-cli/issues/1002#issuecomment-471125831 https://github.com/aws-amplify/amplify-cli/issues/1002#issuecomment-472120075

Describe the solution you’d like The generated template in amplify\backend\awscloudformation\nested-cloudformation-stack.yml should pass the GraphQL API Id Output to all the Lambdas as a parameter. Let’s call the API myamplifytest, then, the resource identifier will be like apimyamplifytest, so, we can get the GraphQL API Id Output and pass as a parameter

"functionmyfunction": {
    "Type": "AWS::CloudFormation::Stack",
    "DependsOn": ["apimyamplifytest"],
    "Properties": {
        "TemplateURL": "https://s3.amazonaws.com/myproject-20190306200305-deployment/amplify-cfn-templates/function/functionmyfunction-cloudformation-template.json",
        "Parameters": {
            "env": "dev",
            "GraphQLAPIId": {
                "Fn::GetAtt": ["apimyamplifytest", "Outputs.GraphQLAPIIdOutput"]
            }
        }
    }
},

Note that all the Lambdas then will need a DependsOn the resource that outputs the GraphQL API Id.

Additional context This will make it easy for people writing custom logic in the Lambdas and trying to get either the GraphQL API Id, a table name, StreamArn or any other output generated using the GraphQL API Id. Implementing this can be a way of dealing with aws-amplify/amplify-category-api#440

[zjullion]

how is this functionality hidden and undocumented?.

I’m not sure why the amplify-cli team has not documented it. I’m just a contributor here (like you!)

Is it gonna be removed? Editing backend-config.json is safe?

I can’t say for certain, but I think it’s fairly safe. When you add / remove resources via amplify cli, this is the file that gets edited. As well, you’ll see dependsOn is used between auth and api resources.

I mean, changes won’t get lost by running amplify push/publish or others commands?

For certain, the changes won’t get lost.

Just remember to always do an 'amplify env checkout <env>` after editing the file.

As well, this file can be used to add 100% custom resources to amplify: https://github.com/aws-amplify/amplify-cli/issues/80#issuecomment-492428916

[zjullion]

@kstro21, you can provide the GraphQLApiIdOutput to the lambdas, just follow something similar to what I mention here: https://github.com/aws-amplify/amplify-cli/issues/1481#issuecomment-493603180