fix: exclude non source files in .dockerignore

[paolofacchinetti]

Existing issue

Right now the COPY . . instruction in the Dockerfile copies pretty almost everything from the repository into the build container (including the .git/ directory, the Dockerfile, the README, etc.) which causes two things:

• slower builds (need to copy everything into the build container)
• Docker build cache invalidation even when files that aren't source code are changed. This leads to full rebuilds of the reth binary instead of using the existing cached build layer

Solution

To fix this, I changed the /.dockerignore file to exclude all but the source files required at build-time. I've tested that this works and produces a working Docker container, while solving the issues i wrote above.

This approach to exclude all but the source files means that when new files are added to the repo that are not source files, they will be ignored by the COPY . . instruction. New files or directories that are required during the build stage can be whitelisted in the .dockerignore file.

[onbjerg]

@paolofacchinetti Please check that this does not break Dockerfile.cross as that is what we use to build releases

[onbjerg]

(see above)

[onbjerg]

Please include the licenses too

[paolofacchinetti]

FYI right now (before my PR) the licenses are copied during the reth binary build stage of the Dockerfile, but are not copied into the final runner container. Which means that the end user that pulls the reth image won't find the licenses in it. It seems pointless to me to copy the licenses during build time only, would you like that I add them to the final runner container by copying them across the various build stages?

[onbjerg]

That would be ideal

[onbjerg]

lgtm

[codecov]

Codecov Report

Merging #3387 (1ddf70d) into main (30a1ad2) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3387      +/-   ##
==========================================
- Coverage   69.40%   69.39%   -0.01%     
==========================================
  Files         537      537              
  Lines       72018    71991      -27     
==========================================
- Hits        49981    49957      -24     
+ Misses      22037    22034       -3     

Flag	Coverage Δ
integration-tests	16.33% <ø> (+0.01%)	⬆️
unit-tests	64.43% <ø> (-0.02%)	⬇️

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see 17 files with indirect coverage changes