S3-backed CI cache helper. A single static Go binary.
cacher is the build that the typical "check S3, fall back to
upstream, upload for next time" shell loop should have been. It downloads,
uploads, lists, and invalidates cached artifacts in any S3-compatible
bucket — single files, docker images (via streamed
save | zstd | s3), and whole directory trees keyed by lockfile
hash. Built for builds.sr.ht; works
anywhere you can run a binary and reach an S3 endpoint.
wget https://bigbes.pages.srht.bigb.es/ci-cacher/cacher-linux-amd64 \
-O ~/.local/bin/cacher
chmod +x ~/.local/bin/cacherVerify the binary against the sha256 below before using it.
# before — install awscli, write ~/.aws/config, then in every task:
if aws s3api head-object --bucket "$B" --key "$K" >/dev/null 2>&1; then
aws s3 cp "s3://$B/$K" "$out"
else
curl -sSL "$url" -o "$out"
aws s3 cp "$out" "s3://$B/$K"
fi# after — one binary, one config, one command:
cacher download "$key" "$out" --url "$url"init / doctor — persist config + smoke-test credsdownload / upload — single file, with --url fallback and --sha256 verifyexists / list / delete / key — management + shell helpersdocker {exists,download,upload} — streamed save/load via zstddir {download,upload} — tar+zstd directory caching, keyed by content hash
Run cacher --help for the full surface. Read
the
README for usage patterns, Garage compatibility notes, and exit-code semantics.
The shell version this replaced repeated five things in every CI task:
install AWS CLI v2 (≈50 MB per build), write a Garage-tuned
~/.aws/config, compute cache keys from file content with
sha256sum | cut, branch HIT/MISS by hand, and for
docker images pipe docker save | zstd | aws s3 cp - (and the
inverse). cacher collapses all of that into one fetched binary
plus a config file. The directory caching is the genuinely new capability —
the shell version only ever handled single files.