bazel-lib/tools/hashes.bzl

67 lines
2.0 KiB
Python

"""Rule for generating integrity files
Default output is a .sha256 file but .sha1 and .md5 files are also available
via output groups.
Based on https://github.com/bazelbuild/examples/blob/main/rules/implicit_output/hash.bzl
"""
def _hash(ctx, algo, file):
coreutils = ctx.toolchains["@aspect_bazel_lib//lib:coreutils_toolchain_type"]
out = ctx.actions.declare_file("{}.{}".format(file.basename, algo), sibling = file)
ctx.actions.run_shell(
outputs = [out],
inputs = [file],
tools = [coreutils.coreutils_info.bin],
# coreutils has --no-names option but it doesn't work in current version, so we have to use cut.
command = """HASH=$({coreutils} hashsum --{algo} {src} | {coreutils} cut -f1 -d " ") && {coreutils} echo -ne "$HASH {basename}" > {out}""".format(
coreutils = coreutils.coreutils_info.bin.path,
algo = algo,
src = file.path,
basename = file.basename,
out = out.path,
),
)
return out
def _impl(ctx):
# Create actions to generate the three output files.
# Actions are run only when the corresponding file is requested.
md5out = _hash(ctx, "md5", ctx.file.src)
sha1out = _hash(ctx, "sha1", ctx.file.src)
sha256out = _hash(ctx, "sha256", ctx.file.src)
# By default (if you run `bazel build` on this target, or if you use it as a
# source of another target), only the sha256 is computed.
return [
DefaultInfo(
files = depset([sha256out]),
),
OutputGroupInfo(
md5 = depset([md5out]),
sha1 = depset([sha1out]),
sha256 = depset([sha256out]),
),
]
_hashes = rule(
implementation = _impl,
toolchains = [
"@aspect_bazel_lib//lib:coreutils_toolchain_type",
],
attrs = {
"src": attr.label(
allow_single_file = True,
mandatory = True,
),
},
)
def hashes(name, src, **kwargs):
_hashes(
name = name,
src = src,
**kwargs
)