glance/doc/source/controllingservers.rst
Eoghan Glynn 132c54f173 Add --capture-output option to glance-control.
Fixes bug 923894

Previously all stdout/err from glance services was discarded
if launched via glance-control.

The --capture-output option allows such output to be instead
captured in the syslog.

Non-termination output should be flushed to ensure timely
arrival in /var/log/messages.

Change-Id: I5c11ad4b9f7f321a3d1cab71e34c2a6707ef1b5e
2012-02-02 22:57:28 +00:00

213 lines
11 KiB
ReStructuredText

..
Copyright 2011 OpenStack, LLC
All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may
not use this file except in compliance with the License. You may obtain
a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
License for the specific language governing permissions and limitations
under the License.
Controlling Glance Servers
==========================
This section describes the ways to start, stop, and reload Glance's server
programs.
Starting a server
-----------------
There are two ways to start a Glance server (either the API server or the
reference implementation registry server that ships with Glance):
* Manually calling the server program
* Using the ``glance-control`` server daemon wrapper program
We recommend using the second way.
Manually starting the server
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The first is by directly calling the server program, passing in command-line
options and a single argument for a ``paste.deploy`` configuration file to
use when configuring the server application.
.. note::
Glance ships with an ``etc/`` directory that contains sample ``paste.deploy``
configuration files that you can copy to a standard configuation directory and
adapt for your own uses. Specifically, bind_host must be set properly.
If you do `not` specifiy a configuration file on the command line, Glance will
do its best to locate a configuration file in one of the
following directories, stopping at the first config file it finds:
* ``$CWD``
* ``~/.glance``
* ``~/``
* ``/etc/glance``
* ``/etc``
The filename that is searched for depends on the server application name. So,
if you are starting up the API server, ``glance-api.conf`` is searched for,
otherwise ``glance-registry.conf``.
If no configuration file is found, you will see an error, like::
$> glance-api
ERROR: Unable to locate any configuration file. Cannot load application glance-api
Here is an example showing how you can manually start the ``glance-api`` server and ``glance-registry`` in a shell.::
$ sudo glance-api glance-api.conf --debug &
jsuh@mc-ats1:~$ 2011-04-13 14:50:12 DEBUG [glance-api] ********************************************************************************
2011-04-13 14:50:12 DEBUG [glance-api] Configuration options gathered from config file:
2011-04-13 14:50:12 DEBUG [glance-api] /home/jsuh/glance-api.conf
2011-04-13 14:50:12 DEBUG [glance-api] ================================================
2011-04-13 14:50:12 DEBUG [glance-api] bind_host 65.114.169.29
2011-04-13 14:50:12 DEBUG [glance-api] bind_port 9292
2011-04-13 14:50:12 DEBUG [glance-api] debug True
2011-04-13 14:50:12 DEBUG [glance-api] default_store file
2011-04-13 14:50:12 DEBUG [glance-api] filesystem_store_datadir /home/jsuh/images/
2011-04-13 14:50:12 DEBUG [glance-api] registry_host 65.114.169.29
2011-04-13 14:50:12 DEBUG [glance-api] registry_port 9191
2011-04-13 14:50:12 DEBUG [glance-api] verbose False
2011-04-13 14:50:12 DEBUG [glance-api] ********************************************************************************
2011-04-13 14:50:12 DEBUG [routes.middleware] Initialized with method overriding = True, and path info altering = True
2011-04-13 14:50:12 DEBUG [eventlet.wsgi.server] (21354) wsgi starting up on http://65.114.169.29:9292/
$ sudo glance-registry glance-registry.conf &
jsuh@mc-ats1:~$ 2011-04-13 14:51:16 INFO [sqlalchemy.engine.base.Engine.0x...feac] PRAGMA table_info("images")
2011-04-13 14:51:16 INFO [sqlalchemy.engine.base.Engine.0x...feac] ()
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Col ('cid', 'name', 'type', 'notnull', 'dflt_value', 'pk')
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (0, u'created_at', u'DATETIME', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (1, u'updated_at', u'DATETIME', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (2, u'deleted_at', u'DATETIME', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (3, u'deleted', u'BOOLEAN', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (4, u'id', u'INTEGER', 1, None, 1)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (5, u'name', u'VARCHAR(255)', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (6, u'disk_format', u'VARCHAR(20)', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (7, u'container_format', u'VARCHAR(20)', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (8, u'size', u'INTEGER', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (9, u'status', u'VARCHAR(30)', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (10, u'is_public', u'BOOLEAN', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (11, u'location', u'TEXT', 0, None, 0)
2011-04-13 14:51:16 INFO [sqlalchemy.engine.base.Engine.0x...feac] PRAGMA table_info("image_properties")
2011-04-13 14:51:16 INFO [sqlalchemy.engine.base.Engine.0x...feac] ()
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Col ('cid', 'name', 'type', 'notnull', 'dflt_value', 'pk')
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (0, u'created_at', u'DATETIME', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (1, u'updated_at', u'DATETIME', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (2, u'deleted_at', u'DATETIME', 0, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (3, u'deleted', u'BOOLEAN', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (4, u'id', u'INTEGER', 1, None, 1)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (5, u'image_id', u'INTEGER', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (6, u'key', u'VARCHAR(255)', 1, None, 0)
2011-04-13 14:51:16 DEBUG [sqlalchemy.engine.base.Engine.0x...feac] Row (7, u'value', u'TEXT', 0, None, 0)
$ ps aux | grep glance
root 20009 0.7 0.1 12744 9148 pts/1 S 12:47 0:00 /usr/bin/python /usr/bin/glance-api glance-api.conf --debug
root 20012 2.0 0.1 25188 13356 pts/1 S 12:47 0:00 /usr/bin/python /usr/bin/glance-registry glance-registry.conf
jsuh 20017 0.0 0.0 3368 744 pts/1 S+ 12:47 0:00 grep glance
Simply supply the configuration file as the first argument
(the ``etc/glance-api.conf`` and ``etc/glance-registry.conf`` sample configuration
files were used in the above example) and then any common options
you want to use (``--debug`` was used above to show some of the debugging
output that the server shows when starting up. Call the server program
with ``--help`` to see all available options you can specify on the
command line.)
For more information on configuring the server via the ``paste.deploy``
configuration files, see the section entitled
:doc:`Configuring Glance servers <configuring>`
Note that the server `daemonizes` itself by using the standard
shell backgrounding indicator, ``&``, in the previous example. For most use cases, we recommend
using the ``glance-control`` server daemon wrapper for daemonizing. See below
for more details on daemonization with ``glance-control``.
Using the ``glance-control`` program to start the server
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The second way to start up a Glance server is to use the ``glance-control``
program. ``glance-control`` is a wrapper script that allows the user to
start, stop, restart, and reload the other Glance server programs in
a fashion that is more conducive to automation and scripting.
Servers started via the ``glance-control`` program are always `daemonized`,
meaning that the server program process runs in the background.
To start a Glance server with ``glance-control``, simply call
``glance-control`` with a server and the word "start", followed by
any command-line options you wish to provide. Start the server with ``glance-control``
in the following way::
$> sudo glance-control [OPTIONS] <SERVER> start [CONFPATH]
.. note::
You must use the ``sudo`` program to run ``glance-control`` currently, as the
pid files for the server programs are written to /var/run/glance/
Here is an example that shows how to start the ``glance-registry`` server
with the ``glance-control`` wrapper script. ::
$ sudo glance-control api start glance-api.conf
Starting glance-api with /home/jsuh/glance.conf
$ sudo glance-control registry start glance-registry.conf
Starting glance-registry with /home/jsuh/glance.conf
$ ps aux | grep glance
root 20038 4.0 0.1 12728 9116 ? Ss 12:51 0:00 /usr/bin/python /usr/bin/glance-api /home/jsuh/glance-api.conf
root 20039 6.0 0.1 25188 13356 ? Ss 12:51 0:00 /usr/bin/python /usr/bin/glance-registry /home/jsuh/glance-registry.conf
jsuh 20042 0.0 0.0 3368 744 pts/1 S+ 12:51 0:00 grep glance
The same configuration files are used by ``glance-control`` to start the
Glance server programs, and you can specify (as the example above shows)
a configuration file when starting the server.
By default, output from glance services is discarded when launched with ``glance-control``.
In order to capture such output via syslog, use the following option:
$ sudo glance-control --capture-output ...
Stopping a server
-----------------
If you started a Glance server manually and did not use the ``&`` backgrounding
function, simply send a terminate signal to the server process by typing
``Ctrl-C``
If you started the Glance server using the ``glance-control`` program, you can
use the ``glance-control`` program to stop it. Simply do the following::
$> sudo glance-control <SERVER> stop
as this example shows::
$> sudo glance-control registry stop
Stopping glance-registry pid: 17602 signal: 15
Restarting a server
-------------------
You can restart a server with the ``glance-control`` program, as demonstrated
here::
$> sudo glance-control registry restart etc/glance-registry.conf
Stopping glance-registry pid: 17611 signal: 15
Starting glance-registry with /home/jpipes/repos/glance/trunk/etc/glance-registry.conf