compose/fig/service.py

527 lines
18 KiB
Python

from __future__ import unicode_literals
from __future__ import absolute_import
from collections import namedtuple
import logging
import re
import os
from operator import attrgetter
import sys
from docker.errors import APIError
from .container import Container
from .progress_stream import stream_output, StreamOutputError
log = logging.getLogger(__name__)
DOCKER_CONFIG_KEYS = ['image', 'command', 'hostname', 'domainname', 'user', 'detach', 'stdin_open', 'tty', 'mem_limit', 'ports', 'environment', 'dns', 'volumes', 'entrypoint', 'privileged', 'volumes_from', 'net', 'working_dir']
DOCKER_CONFIG_HINTS = {
'link' : 'links',
'port' : 'ports',
'privilege' : 'privileged',
'priviliged': 'privileged',
'privilige' : 'privileged',
'volume' : 'volumes',
'workdir' : 'working_dir',
}
VALID_NAME_CHARS = '[a-zA-Z0-9]'
class BuildError(Exception):
def __init__(self, service, reason):
self.service = service
self.reason = reason
class CannotBeScaledError(Exception):
pass
class ConfigError(ValueError):
pass
VolumeSpec = namedtuple('VolumeSpec', 'external internal mode')
ServiceName = namedtuple('ServiceName', 'project service number')
class Service(object):
def __init__(self, name, client=None, project='default', links=None, volumes_from=None, **options):
if not re.match('^%s+$' % VALID_NAME_CHARS, name):
raise ConfigError('Invalid service name "%s" - only %s are allowed' % (name, VALID_NAME_CHARS))
if not re.match('^%s+$' % VALID_NAME_CHARS, project):
raise ConfigError('Invalid project name "%s" - only %s are allowed' % (project, VALID_NAME_CHARS))
if 'image' in options and 'build' in options:
raise ConfigError('Service %s has both an image and build path specified. A service can either be built to image or use an existing image, not both.' % name)
supported_options = DOCKER_CONFIG_KEYS + ['build', 'expose']
for k in options:
if k not in supported_options:
msg = "Unsupported config option for %s service: '%s'" % (name, k)
if k in DOCKER_CONFIG_HINTS:
msg += " (did you mean '%s'?)" % DOCKER_CONFIG_HINTS[k]
raise ConfigError(msg)
self.name = name
self.client = client
self.project = project
self.links = links or []
self.volumes_from = volumes_from or []
self.options = options
def containers(self, stopped=False, one_off=False):
return [Container.from_ps(self.client, container)
for container in self.client.containers(all=stopped)
if self.has_container(container, one_off=one_off)]
def has_container(self, container, one_off=False):
"""Return True if `container` was created to fulfill this service."""
name = get_container_name(container)
if not name or not is_valid_name(name, one_off):
return False
project, name, _number = parse_name(name)
return project == self.project and name == self.name
def get_container(self, number=1):
"""Return a :class:`fig.container.Container` for this service. The
container must be active, and match `number`.
"""
for container in self.client.containers():
if not self.has_container(container):
continue
_, _, container_number = parse_name(get_container_name(container))
if container_number == number:
return Container.from_ps(self.client, container)
raise ValueError("No container found for %s_%s" % (self.name, number))
def start(self, **options):
for c in self.containers(stopped=True):
self.start_container_if_stopped(c, **options)
def stop(self, **options):
for c in self.containers():
log.info("Stopping %s..." % c.name)
c.stop(**options)
def kill(self, **options):
for c in self.containers():
log.info("Killing %s..." % c.name)
c.kill(**options)
def restart(self, **options):
for c in self.containers():
log.info("Restarting %s..." % c.name)
c.restart(**options)
def scale(self, desired_num):
"""
Adjusts the number of containers to the specified number and ensures they are running.
- creates containers until there are at least `desired_num`
- stops containers until there are at most `desired_num` running
- starts containers until there are at least `desired_num` running
- removes all stopped containers
"""
if not self.can_be_scaled():
raise CannotBeScaledError()
# Create enough containers
containers = self.containers(stopped=True)
while len(containers) < desired_num:
containers.append(self.create_container())
running_containers = []
stopped_containers = []
for c in containers:
if c.is_running:
running_containers.append(c)
else:
stopped_containers.append(c)
running_containers.sort(key=lambda c: c.number)
stopped_containers.sort(key=lambda c: c.number)
# Stop containers
while len(running_containers) > desired_num:
c = running_containers.pop()
log.info("Stopping %s..." % c.name)
c.stop(timeout=1)
stopped_containers.append(c)
# Start containers
while len(running_containers) < desired_num:
c = stopped_containers.pop(0)
log.info("Starting %s..." % c.name)
self.start_container(c)
running_containers.append(c)
self.remove_stopped()
def remove_stopped(self, **options):
for c in self.containers(stopped=True):
if not c.is_running:
log.info("Removing %s..." % c.name)
c.remove(**options)
def create_container(self, one_off=False, insecure_registry=False, **override_options):
"""
Create a container for this service. If the image doesn't exist, attempt to pull
it.
"""
container_options = self._get_container_create_options(override_options, one_off=one_off)
try:
return Container.create(self.client, **container_options)
except APIError as e:
if e.response.status_code == 404 and e.explanation and 'No such image' in str(e.explanation):
log.info('Pulling image %s...' % container_options['image'])
output = self.client.pull(
container_options['image'],
stream=True,
insecure_registry=insecure_registry
)
stream_output(output, sys.stdout)
return Container.create(self.client, **container_options)
raise
def recreate_containers(self, **override_options):
"""
If a container for this service doesn't exist, create and start one. If there are
any, stop them, create+start new ones, and remove the old containers.
"""
containers = self.containers(stopped=True)
if not containers:
log.info("Creating %s..." % self._next_container_name(containers))
container = self.create_container(**override_options)
self.start_container(container)
return [(None, container)]
else:
tuples = []
for c in containers:
log.info("Recreating %s..." % c.name)
tuples.append(self.recreate_container(c, **override_options))
return tuples
def recreate_container(self, container, **override_options):
"""Recreate a container. An intermediate container is created so that
the new container has the same name, while still supporting
`volumes-from` the original container.
"""
try:
container.stop()
except APIError as e:
if (e.response.status_code == 500
and e.explanation
and 'no such process' in str(e.explanation)):
pass
else:
raise
intermediate_container = Container.create(
self.client,
image=container.image,
entrypoint=['/bin/echo'],
command=[],
)
intermediate_container.start(volumes_from=container.id)
intermediate_container.wait()
container.remove()
options = dict(override_options)
new_container = self.create_container(**options)
self.start_container(new_container, intermediate_container=intermediate_container)
intermediate_container.remove()
return (intermediate_container, new_container)
def start_container_if_stopped(self, container, **options):
if container.is_running:
return container
else:
log.info("Starting %s..." % container.name)
return self.start_container(container, **options)
def start_container(self, container=None, intermediate_container=None, **override_options):
container = container or self.create_container(**override_options)
options = dict(self.options, **override_options)
ports = dict(split_port(port) for port in options.get('ports') or [])
volume_bindings = dict(
build_volume_binding(parse_volume_spec(volume))
for volume in options.get('volumes') or []
if ':' in volume)
privileged = options.get('privileged', False)
net = options.get('net', 'bridge')
dns = options.get('dns', None)
container.start(
links=self._get_links(link_to_self=options.get('one_off', False)),
port_bindings=ports,
binds=volume_bindings,
volumes_from=self._get_volumes_from(intermediate_container),
privileged=privileged,
network_mode=net,
dns=dns,
)
return container
def start_or_create_containers(self, insecure_registry=False):
containers = self.containers(stopped=True)
if not containers:
log.info("Creating %s..." % self._next_container_name(containers))
new_container = self.create_container(insecure_registry=insecure_registry)
return [self.start_container(new_container)]
else:
return [self.start_container_if_stopped(c) for c in containers]
def get_linked_names(self):
return [s.name for (s, _) in self.links]
def _next_container_name(self, all_containers, one_off=False):
bits = [self.project, self.name]
if one_off:
bits.append('run')
return '_'.join(bits + [str(self._next_container_number(all_containers))])
def _next_container_number(self, all_containers):
numbers = [parse_name(c.name).number for c in all_containers]
return 1 if not numbers else max(numbers) + 1
def _get_links(self, link_to_self):
links = []
for service, link_name in self.links:
for container in service.containers():
links.append((container.name, link_name or service.name))
links.append((container.name, container.name))
links.append((container.name, container.name_without_project))
if link_to_self:
for container in self.containers():
links.append((container.name, self.name))
links.append((container.name, container.name))
links.append((container.name, container.name_without_project))
return links
def _get_volumes_from(self, intermediate_container=None):
volumes_from = []
for volume_source in self.volumes_from:
if isinstance(volume_source, Service):
containers = volume_source.containers(stopped=True)
if not containers:
volumes_from.append(volume_source.create_container().id)
else:
volumes_from.extend(map(attrgetter('id'), containers))
elif isinstance(volume_source, Container):
volumes_from.append(volume_source.id)
if intermediate_container:
volumes_from.append(intermediate_container.id)
return volumes_from
def _get_container_create_options(self, override_options, one_off=False):
container_options = dict((k, self.options[k]) for k in DOCKER_CONFIG_KEYS if k in self.options)
container_options.update(override_options)
container_options['name'] = self._next_container_name(
self.containers(stopped=True, one_off=one_off),
one_off)
# If a qualified hostname was given, split it into an
# unqualified hostname and a domainname unless domainname
# was also given explicitly. This matches the behavior of
# the official Docker CLI in that scenario.
if ('hostname' in container_options
and 'domainname' not in container_options
and '.' in container_options['hostname']):
parts = container_options['hostname'].partition('.')
container_options['hostname'] = parts[0]
container_options['domainname'] = parts[2]
if 'ports' in container_options or 'expose' in self.options:
ports = []
all_ports = container_options.get('ports', []) + self.options.get('expose', [])
for port in all_ports:
port = str(port)
if ':' in port:
port = port.split(':')[-1]
if '/' in port:
port = tuple(port.split('/'))
ports.append(port)
container_options['ports'] = ports
if 'volumes' in container_options:
container_options['volumes'] = dict(
(parse_volume_spec(v).internal, {})
for v in container_options['volumes'])
if 'environment' in container_options:
if isinstance(container_options['environment'], list):
container_options['environment'] = dict(split_env(e) for e in container_options['environment'])
container_options['environment'] = dict(resolve_env(k, v) for k, v in container_options['environment'].iteritems())
if self.can_be_built():
if len(self.client.images(name=self._build_tag_name())) == 0:
self.build()
container_options['image'] = self._build_tag_name()
# Delete options which are only used when starting
for key in ['privileged', 'net', 'dns']:
if key in container_options:
del container_options[key]
return container_options
def build(self, no_cache=False):
log.info('Building %s...' % self.name)
build_output = self.client.build(
self.options['build'],
tag=self._build_tag_name(),
stream=True,
rm=True,
nocache=no_cache,
)
try:
all_events = stream_output(build_output, sys.stdout)
except StreamOutputError, e:
raise BuildError(self, unicode(e))
image_id = None
for event in all_events:
if 'stream' in event:
match = re.search(r'Successfully built ([0-9a-f]+)', event.get('stream', ''))
if match:
image_id = match.group(1)
if image_id is None:
raise BuildError(self)
return image_id
def can_be_built(self):
return 'build' in self.options
def _build_tag_name(self):
"""
The tag to give to images built for this service.
"""
return '%s_%s' % (self.project, self.name)
def can_be_scaled(self):
for port in self.options.get('ports', []):
if ':' in str(port):
return False
return True
def pull(self, insecure_registry=False):
if 'image' in self.options:
log.info('Pulling %s (%s)...' % (self.name, self.options.get('image')))
self.client.pull(
self.options.get('image'),
insecure_registry=insecure_registry
)
NAME_RE = re.compile(r'^([^_]+)_([^_]+)_(run_)?(\d+)$')
def is_valid_name(name, one_off=False):
match = NAME_RE.match(name)
if match is None:
return False
if one_off:
return match.group(3) == 'run_'
else:
return match.group(3) is None
def parse_name(name):
match = NAME_RE.match(name)
(project, service_name, _, suffix) = match.groups()
return ServiceName(project, service_name, int(suffix))
def get_container_name(container):
if not container.get('Name') and not container.get('Names'):
return None
# inspect
if 'Name' in container:
return container['Name']
# ps
for name in container['Names']:
if len(name.split('/')) == 2:
return name[1:]
def parse_volume_spec(volume_config):
parts = volume_config.split(':')
if len(parts) > 3:
raise ConfigError("Volume %s has incorrect format, should be "
"external:internal[:mode]" % volume_config)
if len(parts) == 1:
return VolumeSpec(None, parts[0], 'rw')
if len(parts) == 2:
parts.append('rw')
external, internal, mode = parts
if mode not in ('rw', 'ro'):
raise ConfigError("Volume %s has invalid mode (%s), should be "
"one of: rw, ro." % (volume_config, mode))
return VolumeSpec(external, internal, mode)
def build_volume_binding(volume_spec):
internal = {'bind': volume_spec.internal, 'ro': volume_spec.mode == 'ro'}
external = os.path.expanduser(volume_spec.external)
return os.path.abspath(os.path.expandvars(external)), internal
def split_port(port):
parts = str(port).split(':')
if not 1 <= len(parts) <= 3:
raise ConfigError('Invalid port "%s", should be '
'[[remote_ip:]remote_port:]port[/protocol]' % port)
if len(parts) == 1:
internal_port, = parts
return internal_port, None
if len(parts) == 2:
external_port, internal_port = parts
return internal_port, external_port
external_ip, external_port, internal_port = parts
return internal_port, (external_ip, external_port or None)
def split_env(env):
if '=' in env:
return env.split('=', 1)
else:
return env, None
def resolve_env(key, val):
if val is not None:
return key, val
elif key in os.environ:
return key, os.environ[key]
else:
return key, ''