fix: stage apko cache as a tree artifact (follow-up to #294)#302
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xnox merged 1 commit intoApr 27, 2026
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…#294) After some more testing we noticed that the per-file cp staging introduced in chainguard-dev#294 - which replaced ctx.actions.symlink to fix Bazel 9 sandbox issues - regresses on remote execution. apko's cache is URL-keyed, so when a cached resource's URL ends in its own filename - typical for keyrings, e.g. https://packages.wolfi.dev/os/wolfi-signing.rsa.pub the cache key equals the filename and the entry lands at: .../wolfi-signing.rsa.pub/wolfi-signing.rsa.pub Some remote-execution backends reject declared output paths whose basename equals their parent directory name as REv2 validation failures, so cache staging fails on RBE even though the cp command itself succeeds. Declare the whole cache as a single tree artifact (via ctx.actions.declare_directory) and populate it in one ctx.actions.run_shell. apko sees the identical files at the identical relative paths, but the problematic paths are now contents of the tree artifact rather than individually declared outputs, so per-output validation no longer sees them. copy_to_workdir grows a list-of-Files branch for this; the lockfile, config, and apko binary continue through the existing single-file and directory paths unchanged.
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Ack! thank you!
note I only use apko locally, or via terraform provider apko, and never with remote executors.
It would be interesting how to setup remote executors in github actiona for testing. Do I need to sign up for some service, or can this be mocked with docker or some such?
as ideally all the issues you are seeing should be tested in our CI.
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After some more testing we noticed that the per-file cp staging introduced in #294 - which replaced ctx.actions.symlink to fix Bazel 9 sandbox issues - regresses on remote execution.
apko's cache is URL-keyed, so when a cached resource's URL ends in its own filename - typical for keyrings, e.g.
the cache key equals the filename and the entry lands at:
Some remote-execution backends reject declared output paths whose basename equals their parent directory name as REv2 validation failures, so cache staging fails on RBE even though the cp command itself succeeds.
Declare the whole cache as a single tree artifact (via ctx.actions.declare_directory) and populate it in one ctx.actions.run_shell. apko sees the identical files at the identical relative paths, but the problematic paths are now contents of the tree artifact rather than individually declared outputs, so per-output validation no longer sees them.
copy_to_workdir grows a list-of-Files branch for this; the lockfile, config, and apko binary continue through the existing single-file and directory paths unchanged.