From 1d5e9aefdab06a2574d78e644deed6c6fa1da171 Mon Sep 17 00:00:00 2001 From: Chad Smith Date: Wed, 17 Oct 2018 18:47:35 +0000 Subject: azure: Add apply_network_config option to disable network from IMDS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Azure generates network configuration from the IMDS service and removes any preexisting hotplug network scripts which exist in Azure cloud images. Add a datasource configuration option which allows for writing a default network configuration which sets up dhcp on eth0 and leave the hotplug handling to the cloud-image scripts. To disable network-config from Azure IMDS, add the following to /etc/cloud/cloud.cfg.d/99-azure-no-imds-network.cfg: datasource:   Azure:     apply_network_config: False LP: #1798424 --- cloudinit/sources/DataSourceAzure.py | 11 +++++- doc/rtd/topics/datasources/azure.rst | 46 ++++++++++++++++++++++ tests/unittests/test_datasource/test_azure.py | 56 +++++++++++++++++++++++++-- 3 files changed, 107 insertions(+), 6 deletions(-) diff --git a/cloudinit/sources/DataSourceAzure.py b/cloudinit/sources/DataSourceAzure.py index 39391d01..d0358e96 100644 --- a/cloudinit/sources/DataSourceAzure.py +++ b/cloudinit/sources/DataSourceAzure.py @@ -207,7 +207,9 @@ BUILTIN_DS_CONFIG = { }, 'disk_aliases': {'ephemeral0': RESOURCE_DISK_PATH}, 'dhclient_lease_file': LEASE_FILE, + 'apply_network_config': True, # Use IMDS published network configuration } +# RELEASE_BLOCKER: Xenial and earlier apply_network_config default is False BUILTIN_CLOUD_CONFIG = { 'disk_setup': { @@ -458,7 +460,8 @@ class DataSourceAzure(sources.DataSource): except sources.InvalidMetaDataException as e: LOG.warning('Could not crawl Azure metadata: %s', e) return False - if self.distro and self.distro.name == 'ubuntu': + if (self.distro and self.distro.name == 'ubuntu' and + self.ds_cfg.get('apply_network_config')): maybe_remove_ubuntu_network_config_scripts() # Process crawled data and augment with various config defaults @@ -619,7 +622,11 @@ class DataSourceAzure(sources.DataSource): the blacklisted devices. """ if not self._network_config: - self._network_config = parse_network_config(self._metadata_imds) + if self.ds_cfg.get('apply_network_config'): + nc_src = self._metadata_imds + else: + nc_src = None + self._network_config = parse_network_config(nc_src) return self._network_config diff --git a/doc/rtd/topics/datasources/azure.rst b/doc/rtd/topics/datasources/azure.rst index 559011ef..f73c3694 100644 --- a/doc/rtd/topics/datasources/azure.rst +++ b/doc/rtd/topics/datasources/azure.rst @@ -57,6 +57,52 @@ in order to use waagent.conf with cloud-init, the following settings are recomme ResourceDisk.MountPoint=/mnt +Configuration +------------- +The following configuration can be set for the datasource in system +configuration (in `/etc/cloud/cloud.cfg` or `/etc/cloud/cloud.cfg.d/`). + +The settings that may be configured are: + + * **agent_command**: Either __builtin__ (default) or a command to run to getcw + metadata. If __builtin__, get metadata from walinuxagent. Otherwise run the + provided command to obtain metadata. + * **apply_network_config**: Boolean set to True to use network configuration + described by Azure's IMDS endpoint instead of fallback network config of + dhcp on eth0. Default is True. For Ubuntu 16.04 or earlier, default is False. + * **data_dir**: Path used to read metadata files and write crawled data. + * **dhclient_lease_file**: The fallback lease file to source when looking for + custom DHCP option 245 from Azure fabric. + * **disk_aliases**: A dictionary defining which device paths should be + interpreted as ephemeral images. See cc_disk_setup module for more info. + * **hostname_bounce**: A dictionary Azure hostname bounce behavior to react to + metadata changes. + * **hostname_bounce**: A dictionary Azure hostname bounce behavior to react to + metadata changes. Azure will throttle ifup/down in some cases after metadata + has been updated to inform dhcp server about updated hostnames. + * **set_hostname**: Boolean set to True when we want Azure to set the hostname + based on metadata. + +An example configuration with the default values is provided below: + +.. sourcecode:: yaml + + datasource: + Azure: + agent_command: __builtin__ + apply_network_config: true + data_dir: /var/lib/waagent + dhclient_lease_file: /var/lib/dhcp/dhclient.eth0.leases + disk_aliases: + ephemeral0: /dev/disk/cloud/azure_resource + hostname_bounce: + interface: eth0 + command: builtin + policy: true + hostname_command: hostname + set_hostname: true + + Userdata -------- Userdata is provided to cloud-init inside the ovf-env.xml file. Cloud-init diff --git a/tests/unittests/test_datasource/test_azure.py b/tests/unittests/test_datasource/test_azure.py index 0f4b7bf7..cd6e7e74 100644 --- a/tests/unittests/test_datasource/test_azure.py +++ b/tests/unittests/test_datasource/test_azure.py @@ -256,7 +256,8 @@ scbus-1 on xpt0 bus 0 ]) return dsaz - def _get_ds(self, data, agent_command=None, distro=None): + def _get_ds(self, data, agent_command=None, distro=None, + apply_network=None): def dsdevs(): return data.get('dsdevs', []) @@ -312,6 +313,8 @@ scbus-1 on xpt0 bus 0 data.get('sys_cfg', {}), distro=distro, paths=self.paths) if agent_command is not None: dsrc.ds_cfg['agent_command'] = agent_command + if apply_network is not None: + dsrc.ds_cfg['apply_network_config'] = apply_network return dsrc @@ -434,14 +437,26 @@ fdescfs /dev/fd fdescfs rw 0 0 def test_get_data_on_ubuntu_will_remove_network_scripts(self): """get_data will remove ubuntu net scripts on Ubuntu distro.""" + sys_cfg = {'datasource': {'Azure': {'apply_network_config': True}}} odata = {'HostName': "myhost", 'UserName': "myuser"} data = {'ovfcontent': construct_valid_ovf_env(data=odata), - 'sys_cfg': {}} + 'sys_cfg': sys_cfg} dsrc = self._get_ds(data, distro='ubuntu') dsrc.get_data() self.m_remove_ubuntu_network_scripts.assert_called_once_with() + def test_get_data_on_ubuntu_will_not_remove_network_scripts_disabled(self): + """When apply_network_config false, do not remove scripts on Ubuntu.""" + sys_cfg = {'datasource': {'Azure': {'apply_network_config': False}}} + odata = {'HostName': "myhost", 'UserName': "myuser"} + data = {'ovfcontent': construct_valid_ovf_env(data=odata), + 'sys_cfg': sys_cfg} + + dsrc = self._get_ds(data, distro='ubuntu') + dsrc.get_data() + self.m_remove_ubuntu_network_scripts.assert_not_called() + def test_crawl_metadata_returns_structured_data_and_caches_nothing(self): """Return all structured metadata and cache no class attributes.""" yaml_cfg = "{agent_command: my_command}\n" @@ -523,8 +538,10 @@ fdescfs /dev/fd fdescfs rw 0 0 def test_network_config_set_from_imds(self): """Datasource.network_config returns IMDS network data.""" + sys_cfg = {'datasource': {'Azure': {'apply_network_config': True}}} odata = {} - data = {'ovfcontent': construct_valid_ovf_env(data=odata)} + data = {'ovfcontent': construct_valid_ovf_env(data=odata), + 'sys_cfg': sys_cfg} expected_network_config = { 'ethernets': { 'eth0': {'set-name': 'eth0', @@ -803,9 +820,10 @@ fdescfs /dev/fd fdescfs rw 0 0 @mock.patch('cloudinit.net.generate_fallback_config') def test_imds_network_config(self, mock_fallback): """Network config is generated from IMDS network data when present.""" + sys_cfg = {'datasource': {'Azure': {'apply_network_config': True}}} odata = {'HostName': "myhost", 'UserName': "myuser"} data = {'ovfcontent': construct_valid_ovf_env(data=odata), - 'sys_cfg': {}} + 'sys_cfg': sys_cfg} dsrc = self._get_ds(data) ret = dsrc.get_data() @@ -821,6 +839,36 @@ fdescfs /dev/fd fdescfs rw 0 0 self.assertEqual(expected_cfg, dsrc.network_config) mock_fallback.assert_not_called() + @mock.patch('cloudinit.net.get_interface_mac') + @mock.patch('cloudinit.net.get_devicelist') + @mock.patch('cloudinit.net.device_driver') + @mock.patch('cloudinit.net.generate_fallback_config') + def test_imds_network_ignored_when_apply_network_config_false( + self, mock_fallback, mock_dd, mock_devlist, mock_get_mac): + """When apply_network_config is False, use fallback instead of IMDS.""" + sys_cfg = {'datasource': {'Azure': {'apply_network_config': False}}} + odata = {'HostName': "myhost", 'UserName': "myuser"} + data = {'ovfcontent': construct_valid_ovf_env(data=odata), + 'sys_cfg': sys_cfg} + fallback_config = { + 'version': 1, + 'config': [{ + 'type': 'physical', 'name': 'eth0', + 'mac_address': '00:11:22:33:44:55', + 'params': {'driver': 'hv_netsvc'}, + 'subnets': [{'type': 'dhcp'}], + }] + } + mock_fallback.return_value = fallback_config + + mock_devlist.return_value = ['eth0'] + mock_dd.return_value = ['hv_netsvc'] + mock_get_mac.return_value = '00:11:22:33:44:55' + + dsrc = self._get_ds(data) + self.assertTrue(dsrc.get_data()) + self.assertEqual(dsrc.network_config, fallback_config) + @mock.patch('cloudinit.net.get_interface_mac') @mock.patch('cloudinit.net.get_devicelist') @mock.patch('cloudinit.net.device_driver') -- cgit v1.2.3