Bazel- How to get all transitive sources of a target - bazel

Question

I have a need to write a rule which zips up all transitive config files (*.foo) of an executable (can be custom rule, java_binary and docker container_image).
The config files can appear on the srcs attribute of any attribute of the executable (tars, deps, runtime_deps, etc)
This sounds like it should be rather easy to do with an aspect attached to my rule but I lost my way between the various examples.

Answer 1

sources_aspect.bzl:
SourceFiles = provider(
fields = {
"transitive_source_files": "list of transitive source files of a target",
},
)
#add 'resources' ? if so _accumulate_transitive_config_files needs to check for dep in deps if ConfigFiles in dep
SourceAttr = ["tars", "deps", "runtime_deps", "exports"]
def _accumulate_transitive_source_files(accumulated, deps):
return depset(
transitive = [dep[SourceFiles].transitive_source_files for dep in deps] + [accumulated],
)
def _collect_current_source_files(srcs):
return [file for src in srcs for file in src.files.to_list()]
def _collect_source_files_aspect_impl(target, ctx):
current_source_files = []
if hasattr(ctx.rule.attr, "srcs"):
current_source_files = _collect_current_source_files(ctx.rule.attr.srcs)
if hasattr(ctx.rule.attr, "resources"):
current_source_files = current_source_files + _collect_current_source_files(ctx.rule.attr.resources)
accumulated_source_files = depset(current_source_files)
for attr in SourceAttr:
if hasattr(ctx.rule.attr, attr):
accumulated_source_files = _accumulate_transitive_source_files(accumulated_source_files, getattr(ctx.rule.attr, attr))
return [SourceFiles(transitive_source_files = accumulated_source_files)]
collect_source_files_aspect = aspect(
implementation = _collect_source_files_aspect_impl,
attr_aspects = SourceAttr,
)
sources.bzl
load("//sources/src/main:sources_aspect.bzl", "SourceFiles", "collect_source_files_aspect")
def _owner_to_bazel_file(fileLabel):
workspace = fileLabel.workspace_root
package = fileLabel.package
if 0 < len(workspace):
workspace = workspace + "/"
if 0 < len(package):
package = package + "/"
return workspace + package + "BUILD.bazel"
def _collect_source_files_rule_impl(ctx):
metadata = [ctx.attr.group_id, ctx.attr.artifact_id]
paths = sorted([f.path for f in ctx.attr.main_artifact_name[SourceFiles].transitive_source_files.to_list()])
owners = sorted(depset([_owner_to_bazel_file(f.owner) for f in ctx.attr.main_artifact_name[SourceFiles].transitive_source_files.to_list()] + [_owner_to_bazel_file(ctx.label)]).to_list())
ctx.actions.write(ctx.outputs.sources, "\n".join(metadata + paths + owners))
ctx.actions.write(ctx.outputs.source_files, "{\"groupId\": \"%s\", \"artifactId\": \"%s\", \"sources\": %s, \"buildFiles\": %s}" % (ctx.attr.group_id, ctx.attr.artifact_id, paths, owners))
return DefaultInfo(
runfiles = ctx.runfiles(files = [ctx.outputs.sources, ctx.outputs.source_files]),
)
source_files = rule(
implementation = _collect_source_files_rule_impl,
attrs = {
"main_artifact_name": attr.label(aspects = [collect_source_files_aspect]),
"group_id": attr.string(mandatory = True),
"artifact_id": attr.string(mandatory = True),
},
outputs = {"sources": "%{name}.sources.txt", "source_files": "%{name}.sources.json"},
)