[plugin] Feature: Build docker image

[tadelv]

Add option to PackagePlugin, to build image before building Lambda package

Motivation:

I have a Swift Lambda that has dependencies that require the base docker image to have openssl-dev installed. The default implementation did not work for me - I must have missed something somewhere. Therefore I added another optional step to the packaging plugin to also build the image before the compilation step.

Modifications:

Added two flags, --build-docker-image and --docker-image-platform, which when set will run an additional build step using docker-buildx and use the Dockerfile in the project root to build the image

Result:

When additional arguments are passed to swift package archive and a Dockerfile is present, the plugin will build the image before compiling the Lambda

[tomerd]

thanks @tadelv, thanks for the suggestion and PR. the original design is that you can provide a baseImage which the plugin would use. this could be a vanilla image or one that you created yourself for example with additional system dependencies. building a custom base image is in principal a one-time thing, so wrapping that in the plugin does not seem to add a huge amount of value compared to just running the docker commands on your own and making the image available for future use. thoughts?

[tadelv]

Hi @tomerd, thank you for chiming in! Like I mentioned before, I was sure I missed something :) I'm not familiar enough with Docker to have thought of using a different prebuilt base image. Thank you, this seems like a much better way.

Do I close the PR?