Add Docker image for cargo-pgo

[bioinformatist]

Hey Jakub! Sorry for such a late PR!

To deploy an image with your Docker Hub account, you may need to generate an access token and then add your account and token to this repo's secrets.

I've tested the new workflow with a test-use repository and it works well. These repositories will be deleted once this PR is merged 😄

[Kobzol]

Hi, thanks a lot for the PR!

Regarding the LLVM installation approach, have you tried that BOLT indeed works, both for instrumentation and then for generating samples? I haven't tried with LLVM 18, but with previous versions, the installed bolt-XY package from Ubuntu haven't been functioning properly (#31). It was detected, but failed during instrumentation/sample gathering.

[bioinformatist]

Yeah the BOLT also works well. You can test it locally using cargo-pgo itself in these steps:

Firstly, build the image and get into the container:

git clone https://github.com/bioinformatist/cargo-pgo.git && cd cargo-pgo
docker build -t pgo .
docker run --entrypoint bash -v $(pwd):/workdir --rm -it pgo

Then in the container:

cargo pgo build
/workdir/target/x86_64-unknown-linux-gnu/release/cargo-pgo pgo info
cargo pgo bolt build --with-pgo
/workdir/target/x86_64-unknown-linux-gnu/release/cargo-pgo-bolt-instrumented pgo info
cargo pgo bolt optimize --with-pgo

Below shows the result:

I believe the issue lies in the suffix of the binaries (like the -18 in merge-fdata-18) and the incorrect location of the linking library (.a), which caused the bolt-XY package from Ubuntu to not work. The soft linking (ln -s) in Dockerfile can fix it. While compiling LLVM from the source code is a more elegant way, it spends more time, which maybe not ideal for CI.

[Kobzol]

Ah, I didn't notice the symlinks. That's great, thanks! I left a few comments, mostly I want to simplify the PR a bit.

[bioinformatist]

Got that! I'll finish it ASAP.

[Kobzol]

No need to hurry ;)

[Kobzol]

The resulting files will be owned by root by default 🤔 Maybe we should somehow mention setting a different user ID. But it's probably outside of scope for this README.

[Kobzol]

Thank you! :)