Added support for Redis

fabtools/require/__init__.py

@@ -5,6 +5,7 @@
 import fabtools.require.postgres
 import fabtools.require.mysql
 import fabtools.require.python
+import fabtools.require.redis
 import fabtools.require.service
 import fabtools.require.supervisor
 import fabtools.require.system

fabtools/require/redis.py

@@ -0,0 +1,105 @@
+"""
+Idempotent API for managing Redis instances
+"""
+from fabtools.files import is_file, watch
+from fabtools.deb import *
+
+
+VERSION='2.4.8'
+
+BINARIES = [
+    'redis-benchmark',
+    'redis-check-aof',
+    'redis-check-dump',
+    'redis-cli',
+    'redis-server',
+]
+
+
+def installed_from_source(version=VERSION):
+    """
+    Require Redis to be installed from source
+    """
+    from fabtools import require
+
+    require.user('redis')
+
+    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()
+            require.file(tarball, url='http://redis.googlecode.com/files/' + tarball)
+            run('tar xzf %(tarball)s' % locals())
+
+            # Compile and install binaries
+            require.deb.package('build-essential')
+            with cd('redis-%(version)s' % locals()):
+                run('make')
+
+                for filename in BINARIES:
+                    sudo('cp -pf src/%(filename)s %(dest_dir)s/' % locals())
+                    sudo('chown redis: %(dest_dir)s/%(filename)s' % locals())
+
+
+def instance(name, version=VERSION, **kwargs):
+    """
+    Require a Redis instance to be running
+
+    The instance will be managed using supervisord.
+    """
+    from fabtools import require
+
+    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')
+    require.directory('/var/run/redis', use_sudo=True, owner='redis')
+
+    # Required for background saving
+    require.system.sysctl('vm.overcommit_memory', '1')
+
+    # Set default parameters
+    params = {}
+    params.update(kwargs)
+    params.setdefault('bind', '127.0.0.1')
+    params.setdefault('port', '6379')
+    params.setdefault('logfile', '/var/log/redis/redis-%(name)s.log' % locals())
+    params.setdefault('loglevel', 'verbose')
+    params.setdefault('dbfilename', '/var/db/redis/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
+    need_restart = False
+    def on_change():
+        need_restart = True
+    with watch(config_filename, True, on_change):
+        require.file(config_filename, contents='\n'.join(lines),
+            use_sudo=True, owner='redis')
+
+    # Use supervisord to manage process
+    process_name = 'redis_%s' % name
+    require.supervisor.process(process_name,
+        user='redis',
+        directory='/var/run/redis',
+        command="%(redis_server)s %(config_filename)s" % locals())
+    if need_restart:
+        fabtools.supervisor.restart_process(process_name)