Working Directory is ignored in the Docker Image

[wperron]

I have the following configuration in Terraform:

resource "aws_lambda_function" "this" {
  # ...
  image_config {
    working_directory = "/var/task/foo/bar"
    command           = ["baz.handler"]
  }
}

but the bootstrap script seems to be ignoring the working_directory parameter and tries to import /var/task/baz.js instead of /var/task/foo/bar/baz.js - as a workaround I commented out the parameter and changed the command to ["foo/bar/baz.handler"]

[hayd]

Atm CMD ["foo/bar/baz.handler"] is the way forward. In some sense that's not a workaround but has always been the way to reference files not at the top level.

It's unclear to me how to support working directory... i need to think about it a little more... what you are supposed to do with LAMBDA_TASK_ROOT vs WORKDIR? 🤔

[wperron]

We should run some tests with some of the default runtimes to see how they behave, that might enlighten us as to how to support workdir for the deno runtime.

[hayd]

Not looked into this but my suspicion is what should be done is cd into /var/task and realpath the WORKDIR (initial directory).

# realpath -m --relative-to="/var/task/" "/var/task/foo/bar/baz.handler"
foo/bar/baz.handler

and use this as the HANDLER (if WORKDIR=LAMBDA_TASK_ROOT then above is a noop).

However, for sure there will need to be DENO_DIR tweak (since it's relative atm, but shouldn't be really).