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| | #! /usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0-or-later
#
# Copyright Red Hat
# Author: David Gibson <david@gibson.dropbear.id.au>
"""
Test A Simple Socket Transport
tasst/snh.py - Simulated network hosts for testing
"""
import contextlib
import json
import subprocess
import sys
import exeter
STDOUT = 1
class SnhProcess(contextlib.AbstractContextManager):
"""
A background process running on a SimNetHost
"""
def __init__(self, snh, *cmd, check=True, context_timeout=1.0, **kwargs):
self.snh = snh
self.cmd = cmd
self.check = check
self.context_timeout = float(context_timeout)
self.kwargs = kwargs
def __enter__(self):
self.popen = subprocess.Popen(self.cmd, **self.kwargs)
return self
def run(self, **kwargs):
stdout, stderr = self.popen.communicate(**kwargs)
cp = subprocess.CompletedProcess(self.popen.args,
self.popen.returncode,
stdout, stderr)
if self.check:
cp.check_returncode()
return cp
def terminate(self):
self.popen.terminate()
def kill(self):
self.popen.kill()
def __exit__(self, *exc_details):
try:
self.popen.wait(timeout=self.context_timeout)
except subprocess.TimeoutExpired as e:
self.terminate()
try:
self.popen.wait(timeout=self.context_timeout)
except subprocess.TimeoutExpired:
self.kill()
raise e
class SimNetHost(contextlib.AbstractContextManager):
"""
A (usually virtual or simulated) location where we can execute
commands and configure networks.
"""
def __init__(self, name):
self.name = name # For debugging
def hostify(self, *cmd, **kwargs):
raise NotImplementedError
def __enter__(self):
return self
def __exit__(self, *exc_details):
pass
def output(self, *cmd, **kwargs):
proc = self.fg(*cmd, capture=STDOUT, **kwargs)
return proc.stdout
def fg(self, *cmd, timeout=None, **kwargs):
# We don't use subprocess.run() because it kills without
# attempting to terminate on timeout
with self.bg(*cmd, **kwargs) as proc:
res = proc.run(timeout=timeout)
return res
def bg(self, *cmd, capture=None, **kwargs):
if capture == STDOUT:
kwargs['stdout'] = subprocess.PIPE
hostcmd, kwargs = self.hostify(*cmd, **kwargs)
proc = SnhProcess(self, *hostcmd, **kwargs)
print(f"SimNetHost {self.name}: Started {cmd} => {proc}",
file=sys.stderr)
return proc
def ifs(self):
info = json.loads(self.output('ip', '-j', 'link', 'show'))
return [i['ifname'] for i in info]
# Internal tests
def test_true(self):
with self as snh:
snh.fg('true')
def test_false(self):
with self as snh:
exeter.assert_raises(subprocess.CalledProcessError,
snh.fg, 'false')
def test_echo(self):
msg = 'Hello tasst'
with self as snh:
out = snh.output('echo', f'{msg}')
exeter.assert_eq(out, msg.encode('utf-8') + b'\n')
def test_timeout(self):
with self as snh:
exeter.assert_raises(subprocess.TimeoutExpired, snh.fg,
'sleep', 'infinity', timeout=0.1, check=False)
def test_bg_true(self):
with self as snh:
with snh.bg('true'):
pass
def test_bg_false(self):
with self as snh:
with snh.bg('false') as proc:
exeter.assert_raises(subprocess.CalledProcessError, proc.run)
def test_bg_echo(self):
msg = 'Hello tasst'
with self as snh:
with snh.bg('echo', f'{msg}', capture=STDOUT) as proc:
res = proc.run()
exeter.assert_eq(res.stdout, msg.encode('utf-8') + b'\n')
def test_bg_timeout(self):
with self as snh:
with snh.bg('sleep', 'infinity') as proc:
exeter.assert_raises(subprocess.TimeoutExpired,
proc.run, timeout=0.1)
proc.terminate()
def test_bg_context_timeout(self):
with self as snh:
def run_timeout():
with snh.bg('sleep', 'infinity', context_timeout=0.1):
pass
exeter.assert_raises(subprocess.TimeoutExpired, run_timeout)
def test_has_lo(self):
with self as snh:
assert 'lo' in snh.ifs()
SELFTESTS = [test_true, test_false, test_echo, test_timeout,
test_bg_true, test_bg_false, test_bg_echo, test_bg_timeout,
test_bg_context_timeout,
test_has_lo]
@classmethod
def selftest(cls, setup):
"Register standard snh tests for instance returned by setup"
for t in cls.SELFTESTS:
testid = f'{setup.__qualname__}|{t.__qualname__}'
exeter.register_pipe(testid, setup, t)
# Additional tests only valid if the snh is isolated (no outside
# network connections)
def test_is_isolated(self):
with self as snh:
exeter.assert_eq(snh.ifs(), ['lo'])
ISOLATED_SELFTESTS = [test_is_isolated]
@classmethod
def selftest_isolated(cls, setup):
"Register self tests for an isolated snh example"
cls.selftest(setup)
for t in cls.ISOLATED_SELFTESTS:
testid = f'{setup.__qualname__}|{t.__qualname__}'
exeter.register_pipe(testid, setup, t)
class RealHost(SimNetHost):
"""Represents the host on which the tests are running (as opposed
to some simulated host created by the tests)
"""
def __init__(self):
super().__init__('REAL_HOST')
def hostify(self, *cmd, capable=False, **kwargs):
assert not capable, \
"BUG: Shouldn't run commands with capabilities on host"
return cmd, kwargs
SimNetHost.selftest(RealHost)
|