Terraform: Is it possible to define an empty image based lambda? - amazon-web-services

Question

When defining a lambda of package_type = Zip, it's possible to create a dummy temp.zip file and set it as the lambda's filename.
When created, the lambda will basically have an empty zip, which can later be replaced by something like a continuous delivery pipeline that pushes an artifact to it.
I've noticed this pattern used at work.
However, I'm playing with lambda container images for something personal.
I set it package_type = Image, and set other required arguments (per the Terraform docs). But when I run terraform apply, I get an error saying the lambda's image_uri argument must be set.
What if I don't have an image built yet? Is there some equivalent technique to satisfy the image_uri requirement, to essentially create an "empty" lambda, which I later plan to update via a CD pipeline?
Been looking around but have not yet found a solution.

Answer 1

What if I don't have an image built yet?
Then you can't create container lambda. You have to provide some image url. It can be dummy image that does nothing, but it must preexist before you can create such a lambda function.
Then later you can update the dummy image with something else.

Answer 2

Yes you can! This question has already been answered here, which I've copied below
data "aws_ecr_authorization_token" "token" {}
resource "aws_ecr_repository" "repository" {
name = "lambda-${local.name}-${local.environment}"
image_tag_mutability = "MUTABLE"
tags = local.common_tags
image_scanning_configuration {
scan_on_push = true
}
lifecycle {
ignore_changes = all
}
provisioner "local-exec" {
# This is a 1-time execution to put a dummy image into the ECR repo, so
# terraform provisioning works on the lambda function. Otherwise there is
# a chicken-egg scenario where the lambda can't be provisioned because no
# image exists in the ECR
command = <<EOF
docker login ${data.aws_ecr_authorization_token.token.proxy_endpoint} -u AWS -p ${data.aws_ecr_authorization_token.token.password}
docker pull alpine
docker tag alpine ${aws_ecr_repository.repository.repository_url}:SOME_TAG
docker push ${aws_ecr_repository.repository.repository_url}:SOME_TAG
EOF
}
}