`local start-api --container-env-vars` option does not work

Description:

It is not clear (to me) what --container-env-vars does when used with sam local start-api.

My understanding is that it should set environment variable to underlying docker container which runs lambda (of PackageType::Zip) in sam local environment without having that environment variable defined in template.yaml

when I run:

sam local start-api --container-env-vars sam_local_envs.json --warm-containers EAGER

sam does not set environment variables to container it starts.

Also, it is not clear what kind the format that file should have, is it same format like --env-vars ?

Steps to reproduce:

sam local start-api --container-env-vars sam_local_envs.json --warm-containers EAGER

where sam_local_envs.json is defined like (hoping that at least one key will work) :

{
    "P1": "V1",
    "Parameters": {
        "P2": "V2",
    }
}

function part of template.yaml is something like:

  LambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: bootstrap
      Runtime: provided.al2
      CodeUri: .
      Events:
        HelloApi:
          Type: Api
          Properties:
            Path: /{path_param}
            Method: get
            RestApiId:
              Ref: ApiGatewayApi
    Metadata:
      BuildMethod: makefile

Observed result:

docker inspect of container which sam started returns:

          "Env": [
              "AWS_SAM_LOCAL=true",
              "AWS_LAMBDA_FUNCTION_MEMORY_SIZE=128",
              "AWS_LAMBDA_FUNCTION_TIMEOUT=10",
              "AWS_LAMBDA_FUNCTION_HANDLER=bootstrap",
              "AWS_LAMBDA_FUNCTION_NAME=[REDACTED]",
              "AWS_LAMBDA_FUNCTION_VERSION=$LATEST",
              "AWS_LAMBDA_LOG_GROUP_NAME=aws/lambda/[REDACTED]",
              "AWS_LAMBDA_LOG_STREAM_NAME=$LATEST",
              "AWS_REGION=us-east-1",
              "AWS_DEFAULT_REGION=us-east-1",
              "AWS_ACCESS_KEY_ID=[REDACTED]",
              "AWS_SECRET_ACCESS_KEY=[REDACTED]",
              "AWS_ACCOUNT_ID=[REDACTED]",
              "RUST_BACKTRACE=1",
              "RUST_LOG=trace",
              "LANG=en_US.UTF-8",
              "TZ=:/etc/localtime",
              "PATH=/var/lang/bin:/usr/local/bin:/usr/bin/:/bin:/opt/bin",
              "LD_LIBRARY_PATH=/var/lang/lib:/lib64:/usr/lib64:/var/runtime:/var/runtime/lib:/var/task:/var/task/lib:/opt/lib",
              "LAMBDA_TASK_ROOT=/var/task",
              "LAMBDA_RUNTIME_DIR=/var/runtime"
          ],

Expected result:

environment variables which exists in --container-env-vars file should be set in container

Additional environment details (Ex: Windows, Mac, Amazon Linux etc)

1. OS: MacOS
2. sam --version: SAM CLI, version 1.43.0
3. AWS region:

Add --debug flag to command you are running

[qingchm]

Thanks for your detailed feedback! Let me take a look at this more closely!

[milenkovicm]

thanks @madeupname, that would be one way i know, but that would not preferred way as I wouldn’t like debug related options on configuration which may go to production. if there is an option, someone can flip it 😃

but anyhow, it does not look that this issue is going anywhere anytime soon