MongoDB Cookbook

Installs and configures MongoDB, supporting:

• Single MongoDB instance
• Replication
• Sharding
• Replication and Sharding
• 10gen repository package installation
• 10gen MongoDB Monitoring System

REQUIREMENTS:

This cookbook depends on these external cookbooks

• apt
• python
• runit
• yum

As of 0.16 This Cookbook requires

• Chef > 11
• Ruby > 1.9

Platform:

Currently we 'actively' test using test-kitchen on Ubuntu, Debian, CentOS, Redhat

DEFINITIONS:

This cookbook contains a definition mongodb_instance which can be used to configure a certain type of mongodb instance, like the default mongodb or various components of a sharded setup.

For examples see the USAGE section below.

ATTRIBUTES:

Mongodb Configuration

Basically all settings defined in the Configuration File Options documentation page can be added to the node['mongodb']['config'][<setting>] attribute: http://docs.mongodb.org/manual/reference/configuration-options/

• node['mongodb']['config']['dbpath'] - Location for mongodb data directory, defaults to "/var/lib/mongodb"
• node['mongodb']['config']['logpath] - Path for the logfiles, default is "/var/log/mongodb/mongodb.log"
• node['mongodb']['config']['port] - Port the mongod listens on, default is 27017
• node['mongodb']['config']['rest'] - Enable the ReST interface of the webserver
• node['mongodb']['config']['smallfiles'] - Modify MongoDB to use a smaller default data file size
• node['mongodb']['config']['oplogsize'] - Specifies a maximum size in megabytes for the replication operation log
• node['mongodb']['config']['bind_ip'] - Configure from which address to accept connections
• node['mongodb']['config'][<setting>] - General MongoDB Configuration File option

Cookbook specific attributes

• node[:mongodb][:reload_action] - Action to take when MongoDB conf files are modified, default is "restart"
• node[:mongodb][:package_version] - Version of the MongoDB package to install, default is nil
• node[:mongodb][:client_role] - Role identifying all external clients which should have access to a mongod instance

Sharding and replication attributes

• node['mongodb']['config']['replSet'] - Define name of replicaset
• node[:mongodb][:cluster_name] - Name of the cluster, all members of the cluster must reference to the same name, as this name is used internally to identify all members of a cluster.
• node[:mongodb][:shard_name] - Name of a shard, default is "default"
• node['mongodb']['sharded_collections'] - Define which collections are sharded
• node[:mongodb][:replica_arbiter_only] - Set to true to make node an arbiter.
• node[:mongodb][:replica_build_indexes] - Set to false to omit index creation.
• node[:mongodb][:replica_hidden] - Set to true to hide node from replicaset.
• node[:mongodb][:replica_slave_delay] - Number of seconds to delay slave replication.
• node[:mongodb][:replica_priority] - Node priority.
• node[:mongodb][:replica_tags] - Node tags.
• node[:mongodb][:replica_votes] - Number of votes node will cast in an election.

shared MMS Agent attributes

• node['mongodb']['mms_agent']['api_key'] - MMS Agent API Key. No default, required.
• node['mongodb['mms_agent']['monitoring']['version'] - Version of the MongoDB MMS Monitoring Agent package to download and install. Default is '2.0.0.17-1', required.
• node['mongodb['mms_agent']['monitoring'][<setting>] - General MongoDB MMS Monitoring Agent configuration file option.
• node['mongodb['mms_agent']['backup']['version'] - Version of the MongoDB MMS Backup Agent package to download and install. Default is '1.4.3.28-1', required.
• node['mongodb['mms_agent']['backup'][<setting>] - General MongoDB MMS Monitoring Agent configuration file option.

User management attributes

• node['mongodb']['config']['auth'] - Require authentication to access or modify the database
• node['mongodb']['admin'] - The admin user with userAdmin privileges that allows user management
• node['mongodb']['users'] - Array of users to add when running the user management recipe

Monitoring Agent Settings

The defaults values installed by the package are:

mmsBaseUrl=https://mms.mongodb.com
configCollectionsEnabled=true
configDatabasesEnabled=true
throttlePassesShardChunkCounts = 10
throttlePassesDbstats = 20
throttlePassesOplog = 10
disableProfileDataCollection=false
disableGetLogsDataCollection=false
disableLocksAndRecordStatsDataCollection=false
enableMunin=true
useSslForAllConnections=false
sslRequireValidServerCertificates=false

Backup Agent Settings

The defaults values installed by the package are:

mothership=api-backup.mongodb.com
https=true
sslRequireValidServerCertificates=false

USAGE:

10gen

Adds the stable 10gen repo for the corresponding platform. Currently only implemented for the Debian and Ubuntu repository.

Usage: just add recipe[mongodb::10gen_repo] to the node run_list before any other MongoDB recipe, and the mongodb-10gen stable packages will be installed instead of the distribution default.

Single mongodb instance

Simply add

include_recipe "mongodb::default"

to your recipe. This will run the mongodb instance as configured by your distribution. You can change the dbpath, logpath and port settings (see ATTRIBUTES) for this node by using the mongodb_instance definition:

mongodb_instance "mongodb" do
  port node['application']['port']
end

This definition also allows you to run another mongod instance with a different name on the same node

mongodb_instance "my_instance" do
  port node['mongodb']['port'] + 100
  dbpath "/data/"
end

The result is a new system service with

  /etc/init.d/my_instance <start|stop|restart|status>

Replicasets

Add mongodb::replicaset (instead of mongodb::default) to the node's run_list. Also choose a name for your replicaset cluster and set the value of node[:mongodb][:cluster_name] for each member to this name.

Sharding

You need a few more components, but the idea is the same: identification of the members with their different internal roles (mongos, configserver, etc.) is done via the node[:mongodb][:cluster_name] and node[:mongodb][:shard_name] attributes.

Let's have a look at a simple sharding setup, consisting of two shard servers, one config server and one mongos.

First we would like to configure the two shards. For doing so, just use mongodb::shard in the node's run_list and define a unique mongodb[:shard_name] for each of these two nodes, say "shard1" and "shard2".

Then configure a node to act as a config server - by using the mongodb::configserver recipe.

And finally you need to configure the mongos. This can be done by using the mongodb::mongos recipe. The mongos needs some special configuration, as these mongos are actually doing the configuration of the whole sharded cluster. Most importantly you need to define what collections should be sharded by setting the attribute mongodb[:sharded_collections]:

{
  "mongodb": {
    "sharded_collections": {
      "test.addressbook": "name",
      "mydatabase.calendar": "date"
    }
  }
}

Now mongos will automatically enable sharding for the "test" and the "mydatabase" database. Also the "addressbook" and the "calendar" collection will be sharded, with sharding key "name" resp. "date". In the context of a sharding cluster always keep in mind to use a single role which is added to all members of the cluster to identify all member nodes. Also shard names are important to distinguish the different shards. This is esp. important when you want to replicate shards.

Sharding + Replication

The setup is not much different to the one described above. All you have to do is add the mongodb::replicaset recipe to all shard nodes, and make sure that all shard nodes which should be in the same replicaset have the same shard name.

For more details, you can find a tutorial for Sharding + Replication in the wiki.

MMS Agent

This cookbook also includes support for MongoDB Monitoring System (MMS) agent. MMS is a hosted monitoring service, provided by 10gen, Inc. Once the small python agent program is installed on the MongoDB host, it automatically collects the metrics and uploads them to the MMS server. The graphs of these metrics are shown on the web page. It helps a lot for tackling MongoDB related problems, so MMS is the baseline for all production MongoDB deployments.

To setup MMS, simply set your keys in node['mongodb']['mms_agent']['api_key'] and then add the mongodb::mms-agent recipe to your run list. Your current keys should be available at your MMS Settings page.

User Management

An optional recipe is mongodb::user_management which will enable authentication in the configuration file by default and create any users in the node['mongodb']['users']. The users array expects a hash of username, password, roles, and database. Roles should be an array of roles the user should have on the database given.

If the ::user_management recipe is included, it will enable authentication by setting the node['mongodb']['config']['auth'] to true. This can be overridden in the chef json.

If the auth configuration is true, it will try to create the node['mongodb']['admin'] user, or update them if they already exist. Before using on a new database, ensure you're overwriting the node['mongodb']['admin']['username'] and node['mongodb']['admin']['password'] to something besides their default values.

There's also a user resource which has the actions :add, :modify and :delete. If modify is used on a user that doesn't exist, it will be added. If add is used on a user that exists, it will be modified.

LICENSE and AUTHOR:

Author:: Markus Korn markus.korn@edelight.de

Copyright:: 2011-2014, edelight GmbH

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.