def test_filter():
"""Test that hosts are filtered out if specified."""
message = 'Localhost not allowed'
with pytest.raises(HostSelectException) as excinfo:
select_host([localhost],
blacklist=[localhost],
blacklist_name='Localhost not allowed')
assert message in str(excinfo.value)
def test_metric_command_failure():
"""If the psutil command (or SSH) fails ensure the host is excluded."""
with pytest.raises(HostSelectException) as excinfo:
select_host([localhost],
ranking_string='''
# elephant is not a psutil attribute
# so will cause the command to fail
elephant
''')
assert excinfo.value.data[localhost_fqdn]['get_metrics'] == (
'Command failed (exit: 1)')
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_unreasonable_rankings():
"""Negative test that rankings are evaluated.
(doesn't prove anything by itself hence test_rankings)
"""
with pytest.raises(HostSelectException) as excinfo:
select_host([localhost],
ranking_string='''
# if this test fails due to race conditions
# then you are very lucky
virtual_memory().available > 123456789123456789
getloadavg()[0] < 1
cpu_count() > 512
disk_usage('/').free > 123456789123456789
''')
assert ('virtual_memory().available > 123456789123456789: False') in str(
excinfo.value)
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_rankings():
"""Positive test that rankings are evaluated.
(doesn't prove anything by itself hence test_unreasonable_rankings)
"""
assert select_host([localhost],
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
''') == (localhost, localhost_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_unique():
"""Basic test choosing from multiple forms of localhost"""
name, fqdn = select_host(localhost_aliases + [localhost])
assert name in localhost_aliases + [localhost]
assert fqdn == localhost_fqdn
def test_localhost():
"""Basic test with one host to choose from."""
assert select_host([localhost]) == (localhost, localhost_fqdn)
def test_remote_select():
"""Test host selection works with remote host names."""
assert select_host([remote_platform]) == (remote_platform,
remote_platform_fqdn)
