Source code for fabtools.require.redis

"""
Redis
=====

This module provides high-level tools for managing `Redis`_ instances.

.. _Redis: http://redis.io/

"""
from __future__ import with_statement

from fabric.api import cd, run, settings

from fabtools.files import is_file, watch
from fabtools.system import distrib_family
from fabtools.utils import run_as_root
import fabtools.supervisor


VERSION = '2.6.16'

BINARIES = [
    'redis-benchmark',
    'redis-check-aof',
    'redis-check-dump',
    'redis-cli',
    'redis-sentinel',
    'redis-server',
]


[docs]def installed_from_source(version=VERSION): """ Require Redis to be installed from source. The compiled binaries will be installed in ``/opt/redis-{version}/``. """ from fabtools.require import directory as require_directory from fabtools.require import file as require_file from fabtools.require import user as require_user from fabtools.require.deb import packages as require_deb_packages from fabtools.require.rpm import packages as require_rpm_packages family = distrib_family() if family == 'debian': require_deb_packages([ 'build-essential', ]) elif family == 'redhat': require_rpm_packages([ 'gcc', 'make', ]) require_user('redis', home='/var/lib/redis', system=True) require_directory('/var/lib/redis', owner='redis', use_sudo=True) dest_dir = '/opt/redis-%(version)s' % locals() require_directory(dest_dir, use_sudo=True, owner='redis') if not is_file('%(dest_dir)s/redis-server' % locals()): with cd('/tmp'): # Download and unpack the tarball tarball = 'redis-%(version)s.tar.gz' % locals() url = _download_url(version) + tarball require_file(tarball, url=url) run('tar xzf %(tarball)s' % locals()) # Compile and install binaries with cd('redis-%(version)s' % locals()): run('make') for filename in BINARIES: run_as_root('cp -pf src/%(filename)s %(dest_dir)s/' % locals()) run_as_root('chown redis: %(dest_dir)s/%(filename)s' % locals())
def _download_url(version): if _parse_version(version) <= (2, 6, 14): return 'http://redis.googlecode.com/files/' else: return 'http://download.redis.io/releases/' def _parse_version(version): return tuple(map(int, version.split('.')))
[docs]def instance(name, version=VERSION, bind='127.0.0.1', port=6379, **kwargs): """ Require a Redis instance to be running. The required Redis version will be automatically installed using :py:func:`fabtools.require.redis.installed_from_source` if needed. You can specify the IP address and port on which to listen to using the *bind* and *port* parameters. .. warning:: Redis is designed to be accessed by trusted clients inside trusted environments. It is usually not a good idea to expose the Redis instance directly to the internet. Therefore, with the default settings, the Redis instance will only listen to local clients. If you want to make your Redis instance accessible to other servers over an untrusted network, you should probably add some firewall rules to restrict access. For example: :: from fabtools import require from fabtools.shorewall import Ping, SSH, hosts, rule # The computers that will need to talk to the Redis server REDIS_CLIENTS = [ 'web1.example.com', 'web2.example.com', ] # The Redis server port REDIS_PORT = 6379 # Setup a basic firewall require.shorewall.firewall( rules=[ Ping(), SSH(), rule(port=REDIS_PORT, source=hosts(REDIS_CLIENTS)), ] ) # Make the Redis instance listen on all interfaces require.redis.instance('mydb', bind='0.0.0.0', port=REDIS_PORT) .. seealso:: `Redis Security <http://redis.io/topics/security>`_ You can also use any valid Redis configuration directives as extra keyword arguments. For directives that can be repeated on multiple lines (such as ``save``), you can supply a list of values. The instance will be managed using supervisord, as a process named ``redis_{name}``, running as the ``redis`` user. :: from fabtools import require from fabtools.supervisor import process_status require.redis.instance('mydb') print process_status('redis_mydb') .. seealso:: :ref:`supervisor_module` and :ref:`require_supervisor_module` The default settings enable persistence using periodic RDB snapshots saved in the `/var/db/redis` directory. You may want to use AOF persistence instead: :: require.redis.instance('mydb', appendonly='yes', save=[]) In certain situations, you may want to disable persistence completely: :: require.redis.instance('cache', port=6380, save=[]) .. seealso:: `Redis Persistence <http://redis.io/topics/persistence>`_ """ from fabtools.require import directory as require_directory from fabtools.require import file as require_file from fabtools.require.supervisor import process as require_process from fabtools.require.system import sysctl as require_sysctl installed_from_source(version) require_directory('/etc/redis', use_sudo=True, owner='redis') require_directory('/var/db/redis', use_sudo=True, owner='redis') require_directory('/var/log/redis', use_sudo=True, owner='redis') # Required for background saving with settings(warn_only=True): require_sysctl('vm.overcommit_memory', '1') # Set default parameters params = {} params.update(kwargs) params.setdefault('bind', bind) params.setdefault('port', port) params.setdefault('logfile', '/var/log/redis/redis-%(name)s.log' % locals()) params.setdefault('loglevel', 'verbose') params.setdefault('dir', '/var/db/redis') params.setdefault('dbfilename', 'redis-%(name)s-dump.rdb' % locals()) params.setdefault('save', ['900 1', '300 10', '60 10000']) # Build config file from parameters # (keys such as 'save' may result in multiple config lines) lines = [] for key, value in sorted(params.items()): if isinstance(value, list): for elem in value: lines.append("%s %s" % (key, elem)) else: lines.append("%s %s" % (key, value)) redis_server = '/opt/redis-%(version)s/redis-server' % locals() config_filename = '/etc/redis/%(name)s.conf' % locals() # Upload config file with watch(config_filename, use_sudo=True) as config: require_file(config_filename, contents='\n'.join(lines), use_sudo=True, owner='redis') # Use supervisord to manage process process_name = 'redis_%s' % name require_process( process_name, user='redis', directory='/var/run', command="%(redis_server)s %(config_filename)s" % locals(), ) # Restart if needed if config.changed: fabtools.supervisor.restart_process(process_name)