Merge pull request #15071 from cbodley/wip-qa-dnsmasq

qa: add task for dnsmasq configuration

Reviewed-by: Vasu Kulkarni <vasu@redhat.com>
Reviewed-by: Abhishek Lekshmanan <abhishek.lekshmanan@gmail.com>

qa/tasks/dnsmasq.py

@@ -0,0 +1,102 @@
+"""
+Task for dnsmasq configuration
+"""
+import contextlib
+import logging
+
+from teuthology import misc
+from teuthology.exceptions import ConfigError
+from teuthology import contextutil
+from util import get_remote_for_role
+
+log = logging.getLogger(__name__)
+
+@contextlib.contextmanager
+def setup_dnsmasq(remote, cnames):
+    """ configure dnsmasq on the given remote, adding each cname given """
+    log.info('Configuring dnsmasq on remote %s..', remote.name)
+
+    # back up existing resolv.conf
+    resolv_conf = misc.get_file(remote, '/etc/resolv.conf')
+    # point resolv.conf to local dnsmasq
+    misc.sudo_write_file(remote, '/etc/resolv.conf',
+                         "nameserver 127.0.0.1\n")
+
+    # add address entries to /etc/dnsmasq.d/ceph
+    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.iteritems():
+        dnsmasq += address_template.format(cname=cname, ip_address=ip_address)
+    misc.sudo_write_file(remote, '/etc/dnsmasq.d/ceph', dnsmasq)
+
+    remote.run(args=['cat', '/etc/dnsmasq.d/ceph'])
+    # restart dnsmasq
+    remote.run(args=['sudo', 'systemctl', 'restart', 'dnsmasq'])
+    remote.run(args=['sudo', 'systemctl', 'status', 'dnsmasq'])
+    # verify dns name is set
+    remote.run(args=['ping', '-c', '4', cnames.keys()[0]])
+
+    yield
+
+    log.info('Removing dnsmasq configuration from remote %s..', remote.name)
+    # restore resolv.conf
+    misc.sudo_write_file(remote, '/etc/resolv.conf', resolv_conf)
+    # 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
+    """
+    # 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.iteritems():
+        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:
+                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.iteritems():
+                r = get_remote_for_role(ctx, client)
+                if r is None:
+                    raise ConfigError('no remote for role %s' % client)
+                names[cname] = r.ip_address
+
+        remote_names[remote] = names
+
+    # run a subtask for each unique remote
+    subtasks = []
+    for remote, cnames in remote_names.iteritems():
+        subtasks.extend([ lambda r=remote, cn=cnames: setup_dnsmasq(r, cn) ])
+
+    with contextutil.nested(*subtasks):
+        yield