MySQL

Quest Objectives

  • Install and configure a MySQL server.
  • Add a MySQL user, add a database, and grant permissions.

Getting started

In this quest, we'll continue to explore how existing modules from the Puppet forge can simplify otherwise complex configuration tasks. You will use Puppet Labs' MySQL module to install and configure a server, then explore the custom resource types included with the module. To get started, enter the following command.

quest begin mysql

WhySQL?

The Puppet Labs MySQL module is a great example of how a well-written module can build on Puppet's foundation to simplify a complex configuration task without sacrificing robustness and control.

The module lets you install and configure both server and client MySQL instances, and extends Puppet's standard resource types to let you manage MySQL users, grants, and databases with Puppet's standard resource syntax.

Server install

Task 1:

Before getting started configuring your MySQL server installation, fetch the puppetlabs-mysql module from the Puppet Forge with the puppet module tool.

puppet module install puppetlabs-mysql

With this module installed in the Puppet master's module path, all the included classes are available to classify nodes.

Task 2:

Now we'll edit the site.pp to classify the Learning VM with the MySQL server class.

vim /etc/puppetlabs/code/environments/production/manifests/site.pp

If you completed the NTP quest, you will already have a node declaration for the learning.puppetlabs.vm certname. If not, create it now:

node 'learning.puppetlabs.vm' {

}

Within that node block, you can declare your ::mysql::server class and set its parameters. For this example, we'll specify a root password and set the server's max connections to '1024'. (You may notice that the formatting in vim is a bit funky when typing or pasting nested hashes. You can disable this formatting with the :set paste command in vim.)

node 'learning.puppetlabs.vm' {
  class { '::mysql::server':
    root_password    => 'strongpassword',
    override_options => {
      'mysqld' => { 'max_connections' => '1024' }
    },
  }
}

Notice that in addition to standard parameters like the root_password, the class takes a override_options as a hash, which you can use to address any configuration options you would normally set in the /etc/my.cnf file. Using a hash lets you manage these settings without requiring each to be written into the class as a separate parameter. The structure of the override_options hash is analogous to the [section], var_name = value syntax of a my.cnf file.

Task 3:

Use the puppet parser validate tool to check your syntax, then trigger a puppet run:

puppet agent -t

If you want to check out your new database, you can connect to the MySQL monitor with the mysql command, and exit with the \q command.

To see the result of the 'max_connections' override option you set, use less to open the /etc/my.cnf.d/server.cnf file:

less /etc/my.cnf.d/server.cnf

And you'll see that Puppet translated the hash into appropriate syntax for the MySQL configuration file:

[mysqld]
...
max_connections = 1024

Scope

It was easy enough to use Puppet to install and manage a MySQL server. The puppetlabs-mysql module also includes a bunch of classes that help you manage other aspects of your MySQL deployment.

These classes are organized within the module directory structure in a way that matches Puppet's scope syntax. Scope helps to organize classes, telling Puppet where to look within the module directory structure to find each class. It also separates namespaces within the module and your Puppet manifests, preventing conflicts between variables or classes with the same name.

Take a look at the directories and manifests in the MySQL module. Use the tree command with a filter to include only .pp manifest files:

tree -P "*.pp" /etc/puppetlabs/code/environments/production/modules/mysql/manifests/ 

You'll see something like the following:

/etc/puppetlabs/code/environments/production/modules/mysql/manifests/
├── backup.pp
├── bindings
│   ├── java.pp
│   ├── perl.pp
│   ├── php.pp
│   ├── python.pp
│   └── ruby.pp
├── bindings.pp
├── client
│   └── install.pp
├── client.pp
├── db.pp
├── init.pp
├── params.pp
├── server
│   ├── account_security.pp
│   ├── backup.pp
│   ├── config.pp
│   ├── install.pp
│   ├── monitor.pp
│   ├── mysqltuner.pp
│   ├── providers.pp
│   ├── root_password.pp
│   └── service.pp
└── server.pp

Notice the server.pp manifest in the top level of the mysql/manifests directory.

You were able to declare this class as mysql::server. Based on this scoped class name, Puppet knows to find the class definition in a manifest called server.pp in the manifest directory of the MySQL module.

So mysql::server corresponds to:

/etc/puppetlabs/code/environments/production/modules/mysql/manifests/server.pp

To take an example one level deeper, the mysql::server::account_security class corresponds to:

/etc/puppetlabs/code/environments/production/modules/mysql/manifests/server/account_security.pp

Account security

For security reasons, you will generally want to remove the default users and the 'test' database from a new MySQL installation. The account_security class mentioned above does just this.

Task 4:

Go back to your site.pp manifest and include the mysql::server::account_security class in the learning.puppetlabs.vm node. Remember, you don't need to pass any parameters to this class, so a simple include statement will work in place of a parameterized class declaration.

node 'learning.puppetlabs.vm' {
  include ::mysql::server::account_security
  ...
}

Validate your site.pp

puppet parser validate /etc/puppetlabs/code/environments/production/manifests/site.pp

When it checks out, trigger a puppet run:

puppet agent -t

You will see notices indicating that the test database and two users have been removed:

Notice:
/Stage[main]/Mysql::Server::Account_security/Mysql_database[test]/ensure:
removed
Notice:
/Stage[main]/Mysql::Server::Account_security/Mysql_user[@localhost]/ensure:
removed
Notice:
/Stage[main]/Mysql::Server::Account_security/Mysql_user[[email protected]]/ensure:
removed

(Remember, though, that no automation tool is a substitute for a full understanding your system's security requirements!)

Types and providers

The MySQL module includes some custom types and providers that let you manage some critical bits of MySQL as resources with the Puppet DSL just like you would with a system user or service.

A type defines the interface for a resource: the set of properties you can use to define a desired state for the resource, and the parameters that don't directly map to things on the system, but tell Puppet how to manage the resource. Both properties and parameters appear in the resource declaration syntax as attribute value pairs.

A provider is what does the heavy lifting to bring the system into line with the state defined by a resource declaration. Providers are implemented for a wide variety of supported operating systems. They are a key component of the Resource Abstraction Layer (RAL), translating the universal interface defined by the type into system-specific implementations.

The MySQL module includes custom types and providers that make mysql_user, mysql_database, and mysql_grant available as resources.

Database, user, grant:

Task 5:

These custom resource types make it possible to manage a new database with a few lines of puppet code.

Add the following resource declaration to your site.pp node definition. (Remember the :set paste command if you need it.)

  mysql_database { 'lvm':
      ensure  => present,
      charset => 'utf8',
  }

Similarly, with a user, all you have to do is specify the name and host as the resource title, and set the ensure attribute to present. Enter the following in your node definition as well.

  mysql_user { '[email protected]':
    ensure => present,
  }

Now that you have a user and database, you can use a grant to define the privileges for that user.

Note that the * character will match any table. Thus, table => 'lvm.*' below means that the lvm_user has ALL permissions to all tables in the lvm database.

  mysql_grant { '[email protected]/lvm.*':
    ensure      => present,
    options     => ['GRANT'],
    privileges  => ['ALL'],
    table       => 'lvm.*',
    user        => '[email protected]',
  }

Once you've added declarations for these three custom resources, use the puppet parser validate command on the site.pp manifest to check your syntax

puppet parser validate /etc/puppetlabs/code/environments/production/manifests/site.pp

When your code looks good, trigger a puppet run:

puppet agent -t

Review

In this quest, you learned how to install and make configuration changes to a MySQL server. You also got an overview of how classes are organized within the module structure and how their names within your Puppet manifests reflect this organization.

The MySQL module we used for this quest provides a nice example of how custom types and providers can extend Puppet's available resources to make service or application specific elements easily configurable through Puppet's resource declaration syntax.

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