Lambda@Edge submodule doesn't allow to control log group settings

[bartelemi]

Describe the Feature

Lambda@Edge submodule should allow tweaking the log group settings, like log retention days or kms key. Currently it's creating the log group automatically with default AWS settings, which are not always the most desirable.

Expected Behavior

New variables var.cloudwatch_logs_kms_key_arn and var.cloudwatch_logs_retention_in_days to control the log group settings, with sensible defaults (similar to other modules).

Use Case

Just like for the https://github.com/cloudposse/terraform-aws-lambda-function module, we want to be able to change the log retention days and KMS keys for our lambdas@edge.

Describe Ideal Solution

Introduce 2 new vars as described above, do not create log group automatically, but via the cloudposse/cloudwatch-logs/aws module and tweak the IAM role in this submodule to reflect those changes.

Alternatively, this functionality could be achieved by leveraging the original lambda module, as this lambda@edge submodule is just a more specialized use-case.

Alternatives Considered

As a workaround, we're updating these settings via AWS console.

[szbartnik]

+1