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|
# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Test the cylc.flow.host_select module with hosts.
NOTE: These tests require a remote host to work with and are skipped
unless one is provided.
NOTE: These are functional tests, for unit tests see the docstrings in
the host_select module.
"""
from shlex import quote
import socket
from subprocess import call, DEVNULL
import pytest
from cylc.flow.cfgspec.glbl_cfg import glbl_cfg
from cylc.flow.exceptions import HostSelectException
from cylc.flow.host_select import (
select_host,
select_workflow_host
)
from cylc.flow.hostuserutil import get_fqdn_by_host
local_host, local_host_alises, _ = socket.gethostbyname_ex('localhost')
local_host_fqdn = get_fqdn_by_host(local_host)
try:
# get a suitable remote host for running tests on
# NOTE: do NOT copy this testing approach in other python tests
remote_platform = glbl_cfg().get(
['platforms', '_remote_background_shared_tcp', 'hosts'],
[]
)[0]
# don't run tests unless host is contactable
if call(
['ssh', quote(remote_platform), 'hostname'],
stdin=DEVNULL, stdout=DEVNULL, stderr=DEVNULL
):
raise KeyError('remote platform')
# get the fqdn for this host
remote_platform_fqdn = get_fqdn_by_host(remote_platform)
except (KeyError, IndexError):
pytest.skip('Remote test host not available', allow_module_level=True)
remote_platform = None
def test_remote_select():
"""Test host selection works with remote host names."""
assert select_host([remote_platform]) == (
remote_platform, remote_platform_fqdn
)
def test_remote_blacklict():
"""Test that blacklisting works with remote host names."""
# blacklist by fqdn
with pytest.raises(HostSelectException):
select_host(
[remote_platform],
blacklist=[remote_platform]
)
# blacklist by short name
with pytest.raises(HostSelectException):
select_host(
[remote_platform],
blacklist=[remote_platform_fqdn]
)
# make extra sure filters are really being applied
for _ in range(10):
assert select_host(
[remote_platform, local_host],
blacklist=[remote_platform]
) == (local_host, local_host_fqdn)
def test_remote_rankings():
"""Test that ranking evaluation works on hosts (via SSH)."""
assert select_host(
[remote_platform],
ranking_string='''
# if this test fails due to race conditions
# then you have bigger issues than a test failure
virtual_memory().available > 1
getloadavg()[0] < 500
cpu_count() > 1
disk_usage('/').free > 1
'''
) == (remote_platform, remote_platform_fqdn)
def test_remote_exclude(monkeypatch):
"""Ensure that hosts get excluded if they don't meet the rankings.
Already tested elsewhere but this double-checks that it works if more
than one host is provided to choose from."""
def mocked_get_metrics(hosts, metrics, _=None):
# pretend that ssh to remote_platform failed
return {f'{local_host_fqdn}': {('cpu_count',): 123}}
monkeypatch.setattr(
'cylc.flow.host_select._get_metrics',
mocked_get_metrics
)
assert select_host(
[local_host, remote_platform],
ranking_string='''
cpu_count()
'''
) == (local_host, local_host_fqdn)
def test_remote_workflow_host_select(mock_glbl_cfg):
"""test [scheduler][run hosts]available"""
mock_glbl_cfg(
'cylc.flow.host_select.glbl_cfg',
f'''
[scheduler]
[[run hosts]]
available = {remote_platform}
'''
)
assert select_workflow_host() == (remote_platform, remote_platform_fqdn)
def test_remote_workflow_host_condemned(mock_glbl_cfg):
"""test [scheduler][run hosts]condemned hosts"""
mock_glbl_cfg(
'cylc.flow.host_select.glbl_cfg',
f'''
[scheduler]
[[run hosts]]
available = {remote_platform}, {local_host}
condemned = {remote_platform}
'''
)
for _ in range(10):
assert select_workflow_host() == (local_host, local_host_fqdn)
def test_remote_workflow_host_rankings(mock_glbl_cfg):
"""test [scheduler][run hosts]rankings"""
mock_glbl_cfg(
'cylc.flow.host_select.glbl_cfg',
f'''
[scheduler]
[[run hosts]]
available = {remote_platform}
ranking = """
# if this test fails due to race conditions
# then you are very lucky
virtual_memory().available > 123456789123456789
cpu_count() > 512
disk_usage('/').free > 123456789123456789
"""
'''
)
with pytest.raises(HostSelectException) as excinfo:
select_workflow_host()
# ensure that host selection actually evaluated rankings
assert set(excinfo.value.data[remote_platform_fqdn]) - {'returncode'} == {
'virtual_memory().available > 123456789123456789',
'cpu_count() > 512',
"disk_usage('/').free > 123456789123456789"
}
# ensure that none of the rankings passed
assert not any(excinfo.value.data[remote_platform_fqdn].values())
|
