Merge lp:~james-sapara/charms/precise/redis-master/config-options into lp:charms/redis-master

[James Sapara]

Ability to configure some options in redis which are important for more persistant/reliable data setups.
- port is not configurable, some security/firewall setups work better with control over the port.
- requirepass can be set, enabling a small layer of security. hardly perfect, but better than nothing.
- appendonly can be set to yes or no, to control how redis writes out its logs for replay.
- appendfsync can be set to eversec, no, always to control when it flushes writes

Basically, the default can result in minutes of lost data, which is not a big deal in a cache or LRU setting. Some use cases require a bit more reliability and persistence (token buckets, aggregate metrics, etc). These settings allow you to configure redis to more frequently fsync data, and recover from loss of power/segfault/etc.

If accepted, I can update redis-slave to match functionality.

[Charles Butler (lazypower)]

Greetings James,

I reviewed your changes and attached a bug to the MP to track progress. Please feel free to follow up if you have any questions about the review.

https://bugs.launchpad.net/charms/+bug/1274196

All the best

review: Needs Fixing

[Marco Ceppi (marcoceppi)]

Marking Needs Fixing to remove from queue.

When ready for another review, select "Request another review" and request one from "charmers"

review: Needs Fixing

[Marco Ceppi (marcoceppi)]

When ready for another review please move this item from Work in progress to Needs review. If it's no longer applicable please move to Rejected

Unmerged revisions

9. By James Sapara on 2014-01-07

Added some configurability to allow configuring redis for a more persistant/reliable use case.
- config options for port, requirepass, ppendonly and appendfsync (ease to add more)
- pass along the requirepass to master-relations

=== added file 'config.yaml'
--- config.yaml	1970-01-01 00:00:00 +0000
+++ config.yaml	2014-01-07 20:11:16 +0000
@@ -0,0 +1,34 @@
+options:
+  port:
+    type: int
+    default: 6379
+    description: Port to bind redis on
+
+  requirepass:
+    type: string
+    default: ''
+    description: |
+      Require clients to issue AUTH <PASSWORD> before processing any other
+      commands.  This might be useful in environments in which you do not trust
+      others with access to the host running redis-server.
+
+  appendonly:
+    type: string
+    default: 'no'
+    description: |
+      By default Redis asynchronously dumps the dataset on disk. This mode is
+      good enough in many applications, but an issue with the Redis process or
+      a power outage may result into a few minutes of writes lost (depending on
+      the configured save points).
+
+  appendfsync:
+    type: string
+    default: 'everysec'
+    description: |
+      The default is "everysec", as that's usually the right compromise between
+      speed and data safety. It's up to you to understand if you can relax this to
+      "no" that will let the operating system flush the output buffer when
+      it wants, for better performances (but if you can live with the idea of
+      some data loss consider the default persistence mode that's snapshotting),
+      or on the contrary, use "always" that's very slow but a bit safer than
+      everysec.

=== added file 'hooks/config-changed'
--- hooks/config-changed	1970-01-01 00:00:00 +0000
+++ hooks/config-changed	2014-01-07 20:11:16 +0000
@@ -0,0 +1,48 @@
+#!/bin/bash
+
+############################################################################################################
+# Set debugging
+############################################################################################################
+
+set -ux
+
+############################################################################################################
+# Set Port
+############################################################################################################
+
+PORT=`config-get port`
+open-port "${PORT}/TCP"
+sed -i.bak -e "s/^port.*/port ${PORT}/" /etc/redis/redis.conf
+
+############################################################################################################
+# Require Pass
+############################################################################################################
+
+PASSWORD=`config-get requirepass`
+if [ "${PASSWORD}" = "" ]; then
+  sed -i.bak -e "s/^requirepass.*/requirepass ${PASSWORD}/" /etc/redis/redis.conf
+else
+  sed -i.bak -e "s/^requirepass.*//" /etc/redis/redis.conf
+fi
+
+############################################################################################################
+# Set appendonly
+############################################################################################################
+
+APPENDONLY=`config-get appendonly`
+if [ "${APPENDONLY}" = 'yes' -o "${APPENDONLY}" = 'no' ]; then
+  sed -i.bak -e "s/^appendonly.*/appendonly ${APPENDONLY}/" /etc/redis/redis.conf
+else
+  juju-log "appendonly: ${APPENDONLY} is not valid. Valid options are yes|no"
+fi
+
+############################################################################################################
+# Set appendfsync
+############################################################################################################
+
+APPENDFSYNC=`config-get appendfsync`
+if [ "${APPENDFSYNC}" = 'everysec' -o "${APPENDFSYNC}" = 'no' -o "${APPENDFSYNC}" = 'always' ]; then
+  sed -i.bak -e "s/^appendfsync.*/appendfsync ${APPENDFSYNC}/" /etc/redis/redis.conf
+else
+  juju-log "appendfsync: ${APPENDFSYNC} is not valid. Valid options are everysec|no|always"
+fi

=== modified file 'hooks/install'
--- hooks/install	2013-07-31 12:40:38 +0000
+++ hooks/install	2014-01-07 20:11:16 +0000
@@ -17,6 +17,7 @@
 ############################################################################################################
 
 MY_HOSTNAME=`unit-get public-address`
+PORT=`config-get port`
 
 ############################################################################################################
 # Modify the redis-server configuration file
@@ -28,4 +29,4 @@
 # Open the necessary ports
 ############################################################################################################
 
-open-port 6379/TCP
+open-port "${PORT}/TCP"

=== modified file 'hooks/redis-admin-relation-joined'
--- hooks/redis-admin-relation-joined	2013-02-08 07:36:22 +0000
+++ hooks/redis-admin-relation-joined	2014-01-07 20:11:16 +0000
@@ -20,3 +20,4 @@
 
 echo $JUJU_REMOTE_UNIT joined
 
+

=== modified file 'hooks/redis-master-relation-joined'
--- hooks/redis-master-relation-joined	2013-02-08 07:36:22 +0000
+++ hooks/redis-master-relation-joined	2014-01-07 20:11:16 +0000
@@ -12,12 +12,12 @@
 
 MY_HOSTNAME=`unit-get public-address`
 MY_PORT="6379"
+REQUIREDPASS=`unit-get requiredpass`
 
 ############################################################################################################
 # Set the hostname in the relation so it can be picked up by the _other_ side
 ############################################################################################################
 
-relation-set hostname="${MY_HOSTNAME}" port="${MY_PORT}"
+relation-set hostname="${MY_HOSTNAME}" port="${MY_PORT}" requiredpass="${REQUIREDPASS}"
 
 echo $JUJU_REMOTE_UNIT joined
-

=== modified file 'revision'
--- revision	2011-10-13 08:12:21 +0000
+++ revision	2014-01-07 20:11:16 +0000
@@ -1,1 +1,1 @@
-2
+5