[Feature Request] A "prune" option, or similar.

[casperisfine]

Context

In some situations, (such as docker image building, CI caching, etc), it's desirable to minimize the bundler path footprint.

Current workaround

Here's the script we're using right now:

#!/bin/bash
set -eo pipefail

bundler_root=/tmp/bundle

echo "Cache size before pruning:"
du -sh ${bundler_root}

# Another cache; no value once all gems are installed
rm -rf ${bundler_root}/ruby/*/cache
# git dirs of installed gems are useless once we no longer have to update them
rm -rf ${bundler_root}/ruby/*/bundler/gems/*/.git

find ${bundler_root} -type f \( \
  -iname '*.a' \
  -o -iname '*.o' \
  -o -iname '*.h' \
  -o -iname '*.c' \
  -o -iname '*.d' \
  -o -iname '*.hpp' \
  -o -iname '*.cpp' \
\) -print0 | xargs -0 -n 100 rm -f

echo "Cache size after pruning:"
du -sh ${bundler_root}

And it's quite effective:

Cache size before pruning:
1.7G	/tmp/bundle
Cache size after pruning:
800M	/tmp/bundle

Proposal

This script works well, but I think that if such feature was shipped with bundler itself it would be useful for many more people.

NB: the .a/o/etc removal is probably out of scope for a generic tool, but I think the cache and .git would benefit most people without breaking anything.

[simi]

This is interesting proposal and it seems this is partially fixed by #6133. Any idea how this should work? Should it be default behaviour for frozen install for example or implemented in additional command purge?

[casperisfine]

Should it be default behaviour for frozen install

I didn't think about that, but it's interesting. We could probably assume that if BUNDLE_DEPLOYMENT=1 then you'd like to not keep caches around.

I suppose it could be its own BUNDLE_PRUNE_CACHES option, and BUNDLE_DEPLOYMENT would just enable it, this way you can still opt-out if for some reason it breaks something.