# This file is part of cloud-init. See LICENSE file for license information. import mock import os from textwrap import dedent from cloudinit.net.dhcp import ( InvalidDHCPLeaseFileError, maybe_perform_dhcp_discovery, parse_dhcp_lease_file, dhcp_discovery) from cloudinit.util import ensure_file, write_file from cloudinit.tests.helpers import CiTestCase, wrap_and_call class TestParseDHCPLeasesFile(CiTestCase): def test_parse_empty_lease_file_errors(self): """parse_dhcp_lease_file errors when file content is empty.""" empty_file = self.tmp_path('leases') ensure_file(empty_file) with self.assertRaises(InvalidDHCPLeaseFileError) as context_manager: parse_dhcp_lease_file(empty_file) error = context_manager.exception self.assertIn('Cannot parse empty dhcp lease file', str(error)) def test_parse_malformed_lease_file_content_errors(self): """parse_dhcp_lease_file errors when file content isn't dhcp leases.""" non_lease_file = self.tmp_path('leases') write_file(non_lease_file, 'hi mom.') with self.assertRaises(InvalidDHCPLeaseFileError) as context_manager: parse_dhcp_lease_file(non_lease_file) error = context_manager.exception self.assertIn('Cannot parse dhcp lease file', str(error)) def test_parse_multiple_leases(self): """parse_dhcp_lease_file returns a list of all leases within.""" lease_file = self.tmp_path('leases') content = dedent(""" lease { interface "wlp3s0"; fixed-address 192.168.2.74; option subnet-mask 255.255.255.0; option routers 192.168.2.1; renew 4 2017/07/27 18:02:30; expire 5 2017/07/28 07:08:15; } lease { interface "wlp3s0"; fixed-address 192.168.2.74; option subnet-mask 255.255.255.0; option routers 192.168.2.1; } """) expected = [ {'interface': 'wlp3s0', 'fixed-address': '192.168.2.74', 'subnet-mask': '255.255.255.0', 'routers': '192.168.2.1', 'renew': '4 2017/07/27 18:02:30', 'expire': '5 2017/07/28 07:08:15'}, {'interface': 'wlp3s0', 'fixed-address': '192.168.2.74', 'subnet-mask': '255.255.255.0', 'routers': '192.168.2.1'}] write_file(lease_file, content) self.assertItemsEqual(expected, parse_dhcp_lease_file(lease_file)) class TestDHCPDiscoveryClean(CiTestCase): with_logs = True @mock.patch('cloudinit.net.dhcp.find_fallback_nic') def test_no_fallback_nic_found(self, m_fallback_nic): """Log and do nothing when nic is absent and no fallback is found.""" m_fallback_nic.return_value = None # No fallback nic found self.assertEqual({}, maybe_perform_dhcp_discovery()) self.assertIn( 'Skip dhcp_discovery: Unable to find fallback nic.', self.logs.getvalue()) def test_provided_nic_does_not_exist(self): """When the provided nic doesn't exist, log a message and no-op.""" self.assertEqual({}, maybe_perform_dhcp_discovery('idontexist')) self.assertIn( 'Skip dhcp_discovery: nic idontexist not found in get_devicelist.', self.logs.getvalue()) @mock.patch('cloudinit.net.dhcp.util.which') @mock.patch('cloudinit.net.dhcp.find_fallback_nic') def test_absent_dhclient_command(self, m_fallback, m_which): """When dhclient doesn't exist in the OS, log the issue and no-op.""" m_fallback.return_value = 'eth9' m_which.return_value = None # dhclient isn't found self.assertEqual({}, maybe_perform_dhcp_discovery()) self.assertIn( 'Skip dhclient configuration: No dhclient command found.', self.logs.getvalue()) @mock.patch('cloudinit.temp_utils.os.getuid') @mock.patch('cloudinit.net.dhcp.dhcp_discovery') @mock.patch('cloudinit.net.dhcp.util.which') @mock.patch('cloudinit.net.dhcp.find_fallback_nic') def test_dhclient_run_with_tmpdir(self, m_fback, m_which, m_dhcp, m_uid): """maybe_perform_dhcp_discovery passes tmpdir to dhcp_discovery.""" m_uid.return_value = 0 # Fake root user for tmpdir m_fback.return_value = 'eth9' m_which.return_value = '/sbin/dhclient' m_dhcp.return_value = {'address': '192.168.2.2'} retval = wrap_and_call( 'cloudinit.temp_utils', {'_TMPDIR': {'new': None}, 'os.getuid': 0}, maybe_perform_dhcp_discovery) self.assertEqual({'address': '192.168.2.2'}, retval) self.assertEqual( 1, m_dhcp.call_count, 'dhcp_discovery not called once') call = m_dhcp.call_args_list[0] self.assertEqual('/sbin/dhclient', call[0][0]) self.assertEqual('eth9', call[0][1]) self.assertIn('/var/tmp/cloud-init/cloud-init-dhcp-', call[0][2]) @mock.patch('cloudinit.net.dhcp.util.subp') def test_dhcp_discovery_run_in_sandbox(self, m_subp): """dhcp_discovery brings up the interface and runs dhclient. It also returns the parsed dhcp.leases file generated in the sandbox. """ tmpdir = self.tmp_dir() dhclient_script = os.path.join(tmpdir, 'dhclient.orig') script_content = '#!/bin/bash\necho fake-dhclient' write_file(dhclient_script, script_content, mode=0o755) lease_content = dedent(""" lease { interface "eth9"; fixed-address 192.168.2.74; option subnet-mask 255.255.255.0; option routers 192.168.2.1; } """) lease_file = os.path.join(tmpdir, 'dhcp.leases') write_file(lease_file, lease_content) self.assertItemsEqual( [{'interface': 'eth9', 'fixed-address': '192.168.2.74', 'subnet-mask': '255.255.255.0', 'routers': '192.168.2.1'}], dhcp_discovery(dhclient_script, 'eth9', tmpdir)) # dhclient script got copied with open(os.path.join(tmpdir, 'dhclient')) as stream: self.assertEqual(script_content, stream.read()) # Interface was brought up before dhclient called from sandbox m_subp.assert_has_calls([ mock.call( ['ip', 'link', 'set', 'dev', 'eth9', 'up'], capture=True), mock.call( [os.path.join(tmpdir, 'dhclient'), '-1', '-v', '-lf', lease_file, '-pf', os.path.join(tmpdir, 'dhclient.pid'), 'eth9', '-sf', '/bin/true'], capture=True)])