def get_provider():
"""Get the configured or appropriate provider for the host OS.
If platform is not Linux, use Multipass.
If platform is Linux:
(1) use provider specified with CHARMCRAFT_PROVIDER if running
in developer mode,
(2) use provider specified with snap configuration if running
as snap,
(3) default to platform default (LXD on Linux).
:return: Provider instance.
"""
provider = None
if is_charmcraft_running_in_developer_mode():
provider = os.getenv("CHARMCRAFT_PROVIDER")
if provider is None and is_charmcraft_running_from_snap():
snap_config = get_snap_configuration()
provider = snap_config.provider if snap_config else None
if provider is None:
provider = _get_platform_default_provider()
if provider == "lxd":
return LXDProvider()
elif provider == "multipass":
return MultipassProvider()
raise CraftError(f"Unsupported provider specified {provider!r}.")
def test_get_snap_configuration_empty(mock_snap_config):
def fake_get(key: str):
raise snaphelpers._conf.UnknownConfigKey(key=key)
mock_snap_config.return_value.get.side_effect = fake_get
snap_config = get_snap_configuration()
assert snap_config == CharmcraftSnapConfiguration()
def test_get_snap_configuration_valid_providers(mock_snap_config, provider):
def fake_get(key: str):
if key == "provider":
return provider
raise snaphelpers._conf.UnknownConfigKey(key=key)
mock_snap_config.return_value.get.side_effect = fake_get
snap_config = get_snap_configuration()
assert snap_config == CharmcraftSnapConfiguration(provider=provider)
def test_get_snap_configuration_invalid_providers(mock_snap_config, provider):
def fake_get(key: str):
if key == "provider":
return provider
raise snaphelpers._conf.UnknownConfigKey(key=key)
mock_snap_config.return_value.get.side_effect = fake_get
snap_config = get_snap_configuration()
assert snap_config == CharmcraftSnapConfiguration(provider=provider)
assert snap_config.provider == provider
with pytest.raises(ValueError, match=re.escape(f"provider {provider!r} is not supported")):
validate_snap_configuration(snap_config)