// Wait for a subprocess and test the status code for the following
// conditions of 'expected_status':
// 1. 'None' = Anything but '0'.
// 2. 'Some' = the value of 'expected_status'.
// Returns Nothing if the resulting status code matches the
// expectation otherwise a Failure with the output of the subprocess.
// TODO(jmlvanre): Turn this into a generally useful abstraction for
// gtest where we can have a more straigtforward 'expected_status'.
Future<Nothing> await_subprocess(
const Subprocess& subprocess,
const Option<int>& expected_status = None())
{
// Dup the pipe fd of the subprocess so we can read the output if
// needed.
int out = dup(subprocess.out().get());
// Once we get the status of the process.
return subprocess.status()
.then([=](const Option<int>& status) -> Future<Nothing> {
// If the status is not set, fail out.
if (status.isNone()) {
return Failure("Subprocess status is none");
}
// If the status is not what we expect then fail out with the
// output of the subprocess. The failure message will include
// the assertion failures of the subprocess.
if ((expected_status.isSome() && status.get() != expected_status.get()) ||
(expected_status.isNone() && status.get() == 0)) {
return io::read(out)
.then([](const string& output) -> Future<Nothing> {
return Failure("\n[++++++++++] Subprocess output.\n" + output +
"[++++++++++]\n");
});
}
// If the subprocess ran successfully then return nothing.
return Nothing();
}).onAny([=]() {
os::close(out);
});
}
Future<Version> Docker::_version(const string& cmd, const Subprocess& s)
{
const Option<int>& status = s.status().get();
if (status.isNone() || status.get() != 0) {
string msg = "Failed to execute '" + cmd + "': ";
if (status.isSome()) {
msg += WSTRINGIFY(status.get());
} else {
msg += "unknown exit status";
}
return Failure(msg);
}
CHECK_SOME(s.out());
return io::read(s.out().get())
.then(lambda::bind(&Docker::__version, lambda::_1));
}
