add support for Proxysql cluster

[MaxFedotov]

Add ability to automatically create ProxySQL cluster. $cluster_name determines the name of the cluster, ProxySQL instance will belong to. It will lookup host in PuppetDB and create proxysql_cluster resources with params,it will get from it. Also added $cluster_username and $cluster_password variables

[bastelfreak]

@MaxFedotov can you take a look at the used email address in your commits? It is not associated with your github account.

[MaxFedotov]

I've updated email and made a few more linting fixes + changed style for facts

[bastelfreak]

The code looks good to me, thanks for the updates! @mcrauwel can you please review this as well?

[mcrauwel]

@bastelfreak I have the further testing on my schedule for this week... I will try to finish all pending reviews

[bastelfreak]

Maybe this would also be a good time to add acceptance tests? Something basic like https://github.com/voxpupuli/puppet-collectd/blob/master/spec/acceptance/class_spec.rb would already help a lot.

[mcrauwel]

@MaxFedotov can you rebase on the current master?

[tullis]

@MaxFedotov - Could you possibly share your work on the proxysql::cluster class again please, either here or maybe in an example doc?

I'd be keen to see how you realize the proxysql_server table entries from the virtual resources, and whether that's with a collector, or a realize function.

Many thanks for all of your work on this.

[MaxFedotov]

@tullis
It's some type of profile (or our custom wrapper for default Proxysql module) with following (sorry for formatting issues):

class db::proxysql (
  Db::Common::Cluster_name $cluster_name = undef,
  Optional[String] $version = '1.4.10-1',
  Optional[Proxysql::Server] $mysql_servers = undef,
  Optional[Proxysql::User] $mysql_users = undef,
  Optional[Proxysql::Hostgroup] $mysql_hostgroups = undef,
  Optional[Proxysql::Rule] $mysql_rules = undef,
  Optional[Proxysql::Scheduler] $schedulers = undef,
  Optional[Hash] $override_config_settings = undef,
){
 #some custom code necessary for our environment like creating users and passwords in vault, adding repos and installing additional packages

class { 'proxysql':
    listen_ip => '127.0.0.1',
    mysql_client_package_name => 'Percona-Server-client-56',
    listen_port => 3306,
    admin_listen_ip => '0.0.0.0',
    monitor_username => 'proxysql_monitor',
    manage_proxy_config_file => false,
    split_config => true,
    package_ensure => $version,
    package_provider => 'yum',
    admin_password => $admin_password,
    monitor_password => $monitor_password,
    cluster_password => $cluster_password,
    cluster_name => $cluster_name,
    manage_hostgroup_for_servers => false,
    mysql_servers => $mysql_servers,
    mysql_users => $mysql_users,
    mysql_hostgroups => $mysql_hostgroups,
    mysql_rules => $mysql_rules,
    schedulers => $schedulers,
    sys_owner => 'proxysql',
    sys_group => 'proxysql',
    override_config_settings => $config,
  }

  resources { 'proxy_cluster':
    purge => true,
  }

$query = "resources[parameters] {type = 'Class' and title = 'Proxysql' and parameters.cluster_name = '${cluster_name}'}"
$nodes = puppetdb_query($query).map | $hash | { $hash['parameters']['node_name'] }
$cluster_nodes = length($nodes) ? {
    0       => [$proxysql::node_name],
    default => $nodes,
  }
$cluster_nodes.each |String $node| {
    proxy_cluster { $node:
      hostname => "${split($node, ':')[0]}",
      port     => split($node, ':')[1],
      require  => Class['proxysql']
    }
  }

[tullis]

Thanks @MaxFedotov, that's really useful.