Files
deb-python-dcos/dcos/marathon.py
2015-05-11 17:12:56 -07:00

483 lines
13 KiB
Python

import json
from distutils.version import LooseVersion
from dcos import http, util
from dcos.errors import DCOSException, DefaultError, Error
try:
from urllib import quote
except ImportError:
from urllib.parse import quote
logger = util.get_logger(__name__)
def create_client(config=None):
"""Creates a Marathon client with the supplied configuration.
:param config: configuration dictionary
:type config: config.Toml
:returns: Marathon client
:rtype: dcos.marathon.Client
"""
if config is None:
config = util.get_config()
if config.get('marathon.host') is None or \
config.get('marathon.port') is None:
raise DCOSException(DefaultMarathonError().error())
return Client(config['marathon.host'], config['marathon.port'])
def _to_error(response):
"""
:param response: HTTP response object or Error
:type response: requests.Response or Error
:returns: the error embedded in the response JSON
:rtype: Error
"""
if isinstance(response, Error):
return DefaultMarathonError(response.error())
message = response.json().get('message')
if message is None:
errs = response.json().get('errors')
if errs is None:
logger.error(
'Marathon server did not return a message: %s',
response.json())
return DefaultMarathonError()
msg = '\n'.join(error['error'] for error in errs)
return DefaultMarathonError(msg)
return DefaultError('Error: {}'.format(response.json()['message']))
class Client(object):
"""Class for talking to the Marathon server.
:param host: host for the Marathon server
:type host: str
:param port: port for the Marathon server
:type port: int
"""
def __init__(self, host, port):
self._url_pattern = "http://{host}:{port}/{path}"
self._host = host
self._port = port
version = LooseVersion(self.get_about()["version"])
if version < LooseVersion("0.8.0"):
msg = ("The configured Marathon with version {} is outdated. " +
"Please use version 0.8.0 or later.").format(version)
raise DCOSException(msg)
def _create_url(self, path):
"""Creates the url from the provided path.
:param path: url path
:type path: str
:returns: constructed url
:rtype: str
"""
return self._url_pattern.format(
host=self._host,
port=self._port,
path=path)
def get_about(self):
"""Returns info about Marathon instance
:returns Marathon information
:rtype: dict
"""
url = self._create_url('v2/info')
response = http.get(url, to_error=_to_error)
return response.json()
def get_app(self, app_id, version=None):
"""Returns a representation of the requested application version. If
version is None the return the latest version.
:param app_id: the ID of the application
:type app_id: str
:param version: application version as a ISO8601 datetime
:type version: str
:returns: the requested Marathon application
:rtype: dict
"""
app_id = self.normalize_app_id(app_id)
if version is None:
url = self._create_url('v2/apps{}'.format(app_id))
else:
url = self._create_url(
'v2/apps{}/versions/{}'.format(app_id, version))
response = http.get(url, to_error=_to_error)
# Looks like Marathon return different JSON for versions
if version is None:
return response.json()['app']
else:
return response.json()
def get_app_versions(self, app_id, max_count=None):
"""Asks Marathon for all the versions of the Application up to a
maximum count.
:param app_id: the ID of the application
:type app_id: str
:param max_count: the maximum number of version to fetch
:type max_count: int
:returns: a list of all the version of the application
:rtype: [str]
"""
if max_count is not None and max_count <= 0:
raise DCOSException(
'Maximum count must be a positive number: {}'.format(max_count)
)
app_id = self.normalize_app_id(app_id)
url = self._create_url('v2/apps{}/versions'.format(app_id))
response = http.get(url, to_error=_to_error)
if max_count is None:
return response.json()['versions']
else:
return response.json()['versions'][:max_count]
def get_apps(self):
"""Get a list of known applications.
:returns: list of known applications
:rtype: [dict]
"""
url = self._create_url('v2/apps')
response = http.get(url, to_error=_to_error)
return response.json()['apps']
def add_app(self, app_resource):
"""Add a new application.
:param app_resource: application resource
:type app_resource: dict, bytes or file
:returns: the application description
:rtype: dict
"""
url = self._create_url('v2/apps')
# The file type exists only in Python 2, preventing type(...) is file.
if hasattr(app_resource, 'read'):
app_json = json.load(app_resource)
else:
app_json = app_resource
response = http.post(url,
json=app_json,
to_error=_to_error)
return response.json()
def update_app(self, app_id, payload, force=None):
"""Update an application.
:param app_id: the application id
:type app_id: str
:param payload: the json payload
:type payload: dict
:param force: whether to override running deployments
:type force: bool
:returns: the resulting deployment ID
:rtype: str
"""
app_id = self.normalize_app_id(app_id)
if not force:
params = None
else:
params = {'force': 'true'}
url = self._create_url('v2/apps{}'.format(app_id))
response = http.put(url,
params=params,
json=payload,
to_error=_to_error)
return response.json().get('deploymentId')
def scale_app(self, app_id, instances, force=None):
"""Scales an application to the requested number of instances.
:param app_id: the ID of the application to scale
:type app_id: str
:param instances: the requested number of instances
:type instances: int
:param force: whether to override running deployments
:type force: bool
:returns: the resulting deployment ID
:rtype: bool
"""
app_id = self.normalize_app_id(app_id)
if not force:
params = None
else:
params = {'force': 'true'}
url = self._create_url('v2/apps{}'.format(app_id))
response, error = http.put(url,
params=params,
json={'instances': int(instances)},
to_error=_to_error)
if error is not None:
return (None, error)
deployment = response.json()['deploymentId']
return (deployment, None)
def stop_app(self, app_id, force=None):
"""Scales an application to zero instances.
:param app_id: the ID of the application to stop
:type app_id: str
:param force: whether to override running deployments
:type force: bool
:returns: the resulting deployment ID
:rtype: bool
"""
return self.scale_app(app_id, 0, force)
def remove_app(self, app_id, force=None):
"""Completely removes the requested application.
:param app_id: the ID of the application to remove
:type app_id: str
:param force: whether to override running deployments
:type force: bool
:rtype: None
"""
app_id = self.normalize_app_id(app_id)
if not force:
params = None
else:
params = {'force': 'true'}
url = self._create_url('v2/apps{}'.format(app_id))
http.delete(url, params=params, to_error=_to_error)
def restart_app(self, app_id, force=None):
"""Performs a rolling restart of all of the tasks.
:param app_id: the id of the application to restart
:type app_id: str
:param force: whether to override running deployments
:type force: bool
:returns: the deployment id and version
:rtype: dict
"""
app_id = self.normalize_app_id(app_id)
if not force:
params = None
else:
params = {'force': 'true'}
url = self._create_url('v2/apps{}/restart'.format(app_id))
response = http.post(url,
params=params,
to_error=_to_error)
return response.json()
def get_deployment(self, deployment_id):
"""Returns a deployment.
:param deployment_id: the deployment id
:type deployment_id: str
:returns: a deployment
:rtype: dict
"""
url = self._create_url('v2/deployments')
response = http.get(url,
to_error=_to_error)
deployment = next(
(deployment for deployment in response.json()
if deployment_id == deployment['id']),
None)
return deployment
def get_deployments(self, app_id=None):
"""Returns a list of deployments, optionally limited to an app.
:param app_id: the id of the application
:type app_id: str
:returns: a list of deployments
:rtype: list of dict
"""
url = self._create_url('v2/deployments')
response = http.get(url, to_error=_to_error)
if app_id is not None:
app_id = self.normalize_app_id(app_id)
deployments = [
deployment for deployment in response.json()
if app_id in deployment['affectedApps']
]
else:
deployments = response.json()
return deployments
def _cancel_deployment(self, deployment_id, force):
"""Cancels an application deployment.
:param deployment_id: the deployment id
:type deployment_id: str
:param force: if set to `False`, stop the deployment and
create a new rollback deployment to reinstate the
previous configuration. If set to `True`, simply stop the
deployment.
:type force: bool
:returns: cancelation deployment
:rtype: dict
"""
if not force:
params = None
else:
params = {'force': 'true'}
url = self._create_url('v2/deployments/{}'.format(deployment_id))
response = http.delete(
url,
params=params,
to_error=_to_error)
if force:
return None
else:
return response.json()
def rollback_deployment(self, deployment_id):
"""Rolls back an application deployment.
:param deployment_id: the deployment id
:type deployment_id: str
:returns: cancelation deployment
:rtype: dict
"""
return self._cancel_deployment(deployment_id, False)
def stop_deployment(self, deployment_id):
"""Stops an application deployment.
:param deployment_id: the deployment id
:type deployment_id: str
:rtype: None
"""
self._cancel_deployment(deployment_id, True)
def get_tasks(self, app_id):
"""Returns a list of tasks, optionally limited to an app.
:param app_id: the id of the application to restart
:type app_id: str
:returns: a list of tasks
:rtype: [dict]
"""
url = self._create_url('v2/tasks')
response = http.get(url, to_error=_to_error)
if app_id is not None:
app_id = self.normalize_app_id(app_id)
tasks = [
task for task in response.json()['tasks']
if app_id == task['appId']
]
else:
tasks = response.json()['tasks']
return tasks
def get_task(self, task_id):
"""Returns a task
:param task_id: the id of the task
:type task_id: str
:returns: a tasks
:rtype: dict
"""
url = self._create_url('v2/tasks')
response = http.get(url, to_error=_to_error)
task = next(
(task for task in response.json()['tasks']
if task_id == task['id']),
None)
return task
def normalize_app_id(self, app_id):
"""Normalizes the application id.
:param app_id: raw application ID
:type app_id: str
:returns: normalized application ID
:rtype: str
"""
return quote('/' + app_id.strip('/'))
class DefaultMarathonError(DefaultError):
"""Construct a basic Error class for Marathon
:param message: String to use for additional messaging
:type message: str
"""
def __init__(self, message=""):
self._message = "Error: Marathon likely misconfigured. " + \
"Please check your marathon port and host settings. " + \
message