diff options
Diffstat (limited to 'qa/tasks/dnsmasq.py')
| -rw-r--r-- | qa/tasks/dnsmasq.py | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/qa/tasks/dnsmasq.py b/qa/tasks/dnsmasq.py new file mode 100644 index 000000000..df8ccecb1 --- /dev/null +++ b/qa/tasks/dnsmasq.py @@ -0,0 +1,170 @@ +""" +Task for dnsmasq configuration +""" +import contextlib +import logging + +from teuthology import misc +from teuthology.exceptions import ConfigError +from teuthology import contextutil +from teuthology import packaging +from tasks.util import get_remote_for_role + +log = logging.getLogger(__name__) + +@contextlib.contextmanager +def install_dnsmasq(remote): + """ + If dnsmasq is not installed, install it for the duration of the task. + """ + try: + existing = packaging.get_package_version(remote, 'dnsmasq') + except: + existing = None + + if existing is None: + packaging.install_package('dnsmasq', remote) + try: + yield + finally: + if existing is None: + packaging.remove_package('dnsmasq', remote) + +@contextlib.contextmanager +def backup_resolv(remote, path): + """ + Store a backup of resolv.conf in the testdir and restore it after the task. + """ + remote.run(args=['cp', '/etc/resolv.conf', path]) + try: + yield + finally: + # restore with 'cp' to avoid overwriting its security context + remote.run(args=['sudo', 'cp', path, '/etc/resolv.conf']) + remote.run(args=['rm', path]) + +@contextlib.contextmanager +def replace_resolv(remote, path): + """ + Update resolv.conf to point the nameserver at localhost. + """ + remote.write_file(path, "nameserver 127.0.0.1\n") + try: + # install it + if remote.os.package_type == "rpm": + # for centos ovh resolv.conf has immutable attribute set + remote.run(args=['sudo', 'chattr', '-i', '/etc/resolv.conf'], check_status=False) + remote.run(args=['sudo', 'cp', path, '/etc/resolv.conf']) + yield + finally: + remote.run(args=['rm', path]) + +@contextlib.contextmanager +def setup_dnsmasq(remote, testdir, cnames): + """ configure dnsmasq on the given remote, adding each cname given """ + log.info('Configuring dnsmasq on remote %s..', remote.name) + + # add address entries for each cname + dnsmasq = "server=8.8.8.8\nserver=8.8.4.4\n" + address_template = "address=/{cname}/{ip_address}\n" + for cname, ip_address in cnames.items(): + dnsmasq += address_template.format(cname=cname, ip_address=ip_address) + + # write to temporary dnsmasq file + dnsmasq_tmp = '/'.join((testdir, 'ceph.tmp')) + remote.write_file(dnsmasq_tmp, dnsmasq) + + # move into /etc/dnsmasq.d/ + dnsmasq_path = '/etc/dnsmasq.d/ceph' + remote.run(args=['sudo', 'mv', dnsmasq_tmp, dnsmasq_path]) + # restore selinux context if necessary + remote.run(args=['sudo', 'restorecon', dnsmasq_path], check_status=False) + + # restart dnsmasq + remote.run(args=['sudo', 'systemctl', 'restart', 'dnsmasq']) + # verify dns name is set + remote.run(args=['ping', '-c', '4', next(iter(cnames.keys()))]) + + try: + yield + finally: + log.info('Removing dnsmasq configuration from remote %s..', remote.name) + # remove /etc/dnsmasq.d/ceph + remote.run(args=['sudo', 'rm', dnsmasq_path]) + # restart dnsmasq + remote.run(args=['sudo', 'systemctl', 'restart', 'dnsmasq']) + +@contextlib.contextmanager +def task(ctx, config): + """ + Configures dnsmasq to add cnames for teuthology remotes. The task expects a + dictionary, where each key is a role. If all cnames for that role use the + same address as that role, the cnames can be given as a list. For example, + this entry configures dnsmasq on the remote associated with client.0, adding + two cnames for the ip address associated with client.0: + + - dnsmasq: + client.0: + - client0.example.com + - c0.example.com + + If the addresses do not all match the given role, a dictionary can be given + to specify the ip address by its target role. For example: + + - dnsmasq: + client.0: + client.0.example.com: client.0 + client.1.example.com: client.1 + + Cnames that end with a . are treated as prefix for the existing hostname. + For example, if the remote for client.0 has a hostname of 'example.com', + this task will add cnames for dev.example.com and test.example.com: + + - dnsmasq: + client.0: [dev., test.] + """ + # apply overrides + overrides = config.get('overrides', {}) + misc.deep_merge(config, overrides.get('dnsmasq', {})) + + # multiple roles may map to the same remote, so collect names by remote + remote_names = {} + for role, cnames in config.items(): + remote = get_remote_for_role(ctx, role) + if remote is None: + raise ConfigError('no remote for role %s' % role) + + names = remote_names.get(remote, {}) + + if isinstance(cnames, list): + # when given a list of cnames, point to local ip + for cname in cnames: + if cname.endswith('.'): + cname += remote.hostname + names[cname] = remote.ip_address + elif isinstance(cnames, dict): + # when given a dict, look up the remote ip for each + for cname, client in cnames.items(): + r = get_remote_for_role(ctx, client) + if r is None: + raise ConfigError('no remote for role %s' % client) + if cname.endswith('.'): + cname += r.hostname + names[cname] = r.ip_address + + remote_names[remote] = names + + testdir = misc.get_testdir(ctx) + resolv_bak = '/'.join((testdir, 'resolv.bak')) + resolv_tmp = '/'.join((testdir, 'resolv.tmp')) + + # run subtasks for each unique remote + subtasks = [] + for remote, cnames in remote_names.items(): + subtasks.extend([ lambda r=remote: install_dnsmasq(r) ]) + subtasks.extend([ lambda r=remote: backup_resolv(r, resolv_bak) ]) + subtasks.extend([ lambda r=remote: replace_resolv(r, resolv_tmp) ]) + subtasks.extend([ lambda r=remote, cn=cnames: setup_dnsmasq(r, testdir, cn) ]) + + with contextutil.nested(*subtasks): + yield |