ceph/teuthology/orchestra/cluster.py

106 lines
3.5 KiB
Python

class Cluster(object):
"""
Manage SSH connections to a cluster of machines.
"""
def __init__(self, remotes=None):
"""
Initialize
"""
self.remotes = {}
if remotes is not None:
for remote, roles in remotes:
self.add(remote, roles)
def __repr__(self):
remotes = [(k, v) for k,v in self.remotes.items()]
remotes.sort(key=lambda tup: tup[0].name)
remotes = '{' + ', '.join('{remote!r}: {roles!r}'.format(remote=k, roles=v) for k,v in remotes) + '}'
return '{classname}(remotes={remotes})'.format(
classname=self.__class__.__name__,
remotes=remotes,
)
def __str__(self):
remotes = list(self.remotes.items())
remotes.sort(key=lambda tup: tup[0].name)
remotes = ((k, ','.join(v)) for k,v in remotes)
remotes = ('{k}[{v}]'.format(k=k, v=v) for k,v in remotes)
return ' '.join(remotes)
def add(self, remote, roles):
if remote in self.remotes:
raise RuntimeError(
'Remote {new!r} already found in remotes: {old!r}'.format(
new=remote,
old=self.remotes[remote],
),
)
self.remotes[remote] = list(roles)
def run(self, **kwargs):
"""
Run a command on all the nodes in this cluster.
Goes through nodes in alphabetical order.
If you don't specify wait=False, this will be sequentially.
Returns a list of `RemoteProcess`.
"""
remotes = sorted(self.remotes.iterkeys(), key=lambda rem: rem.name)
return [remote.run(**kwargs) for remote in remotes]
def only(self, *roles):
"""
Return a cluster with only the remotes that have all of given roles.
For roles given as strings, they are matched against the roles
on a remote, and the remote passes the check only if all the
roles listed are present.
Argument can be callable, and will act as a match on roles of
the remote. The matcher will be evaluated one role at a time,
but a match on any role is good enough. Note that this is
subtly diffent from the behavior of string roles, but is
logical if you consider a callable to be similar to passing a
non-string object with an `__eq__` method.
For example::
web = mycluster.only(lambda role: role.startswith('web-'))
"""
c = self.__class__()
want = frozenset(r for r in roles if not callable(r))
matchers = [r for r in roles if callable(r)]
for remote, has_roles in self.remotes.iteritems():
# strings given as roles must all match
if frozenset(has_roles) & want != want:
# not a match
continue
# every matcher given must match at least one role
if not all(
any(matcher(role) for role in has_roles)
for matcher in matchers
):
continue
c.add(remote, has_roles)
return c
def exclude(self, *roles):
"""
Return a cluster *without* remotes that have all of given roles.
This is the opposite of `only`.
"""
matches = self.only(*roles)
c = self.__class__()
for remote, has_roles in self.remotes.iteritems():
if remote not in matches.remotes:
c.add(remote, has_roles)
return c