如何在Bazel规则中运行其他规则的可执行程序

Question

假设我有一个自定义规则my_object。它看起来像：

my_object(
name = "foo",
deps = [
//services/image-A:push,
//services/image-B:push,
]
)

其中，deps中的标签是rules_docker的container_push规则。

我希望能够bazel run //:foo，并让它在deps列表中推送Docker映像。我该怎么做？

这似乎是一种特定的情况，通常只想在自定义规则的可执行文件中运行其他规则的可运行文件。

Answer 1

这里要做的是让my_object输出一个执行其他可执行文件的可执行文件。

考虑这个例子：

def _impl1(ctx):
ctx.actions.write(
output = ctx.outputs.executable,
is_executable = True,
content = "echo %s 123" % ctx.label.name)
return DefaultInfo(executable = ctx.outputs.executable)

exec_rule1 = rule(
implementation = _impl1,
executable = True,
)

def _impl2(ctx):
executable_paths = []
runfiles = ctx.runfiles()
for dep in ctx.attr.deps:
# the "./" is needed if the executable is in the current directory
# (i.e. in the workspace root)
executable_paths.append("./" + dep.files_to_run.executable.short_path)
# collect the runfiles of the other executables so their own runfiles
# will be available when the top-level executable runs
runfiles = runfiles.merge(dep.default_runfiles)
ctx.actions.write(
output = ctx.outputs.executable,
is_executable = True,
content = "n".join(executable_paths))
return DefaultInfo(
executable = ctx.outputs.executable,
runfiles = runfiles)

exec_rule2 = rule(
implementation = _impl2,
executable = True,
attrs = {
"deps": attr.label_list(),
},
)

BUILD.bazel:

load(":defs.bzl", "exec_rule1", "exec_rule2")
exec_rule1(name = "foo")
exec_rule1(name = "bar")
exec_rule2(name = "baz", deps = [":foo", ":bar"])

然后运行它：

$ bazel run //:baz
INFO: Analyzed target //:baz (4 packages loaded, 19 targets configured).
INFO: Found 1 target...
Target //:baz up-to-date:
bazel-bin/baz
INFO: Elapsed time: 0.211s, Critical Path: 0.01s
INFO: 0 processes.
INFO: Build completed successfully, 6 total actions
INFO: Build completed successfully, 6 total actions
foo 123
bar 123

Answer 2

我通过在规则中实现DefaultInfo来实现这一点。

def build_all_impl(ctx):
targets = ctx.attr.targets
run_files = []
for target in targets:
run_files = run_files + target.files.to_list()
DefaultInfo(
runfiles = ctx.runfiles(run_files),
)
build_all = rule(
implementation = build_all_impl,
attrs = {
"targets": attr.label_list(
doc = "target to build",
),
},
)

然后通过运行build_all规则

build_all(
name = "all",
targets = [
":target-1",
":target-2",
...
],
)