Create /etc/my.cnf.d/tripleo.cnf with proper bind-address

When fixing LP#1643487 we added ?bind_address to all DB URIs.
Since this clashes with Cellsv2 due to the URIs becoming host
dependent, we need a new approach to pass bind_address to pymysql
that leaves the DB URIs host-independent.

We first create a /etc/my.cnf.d/tripleo.cnf file with a [tripleo]
section and in this section we add the correct bind-address option.
Note that we use the puppet augeas lens and not the mysql one
because the mysql one does not support custom sections *and* there
are older versions around which do not like the /etc/my.cnf.d/* path.

The reason for not reusing an existing mariadb file (my.cnf or
galera.cnf) is that pymysql's ini file support is not robust
enough at the moment: https://github.com/PyMySQL/PyMySQL/issues/548

The reason for putting this file creation code only on the controller
nodes the following: The slow VIP failover only happens if a
service runs where the VIPs exist. The VIPs get created in the
haproxy profile and that is why in order to have fast VIP failovers
the MySQLClient profile must live where the Haproxy service is running.

Co-Authored-By: Damien Ciabrini <dciabrin@redhat.com>

Partial-Bug: #1663181
Change-Id: Iff8bd2d9ee85f7bb1445aa2e1b3cfbff1f397b18
(cherry picked from commit f6116ff0f3)

manifests/profile/base/database/mysql/client.pp

@@ -0,0 +1,72 @@
+# Copyright 2016 Red Hat, Inc.
+#
+# 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.
+#
+# == Class: tripleo::profile::base::haproxy
+#
+# Loadbalancer profile for tripleo
+#
+# === Parameters
+#
+# [*mysql_read_default_file*]
+#   (Optional) Name of the file that will be passed to pymysql connection strings
+#   Defaults to hiera('tripleo::profile::base:database::mysql::read_default_file', '/etc/my.cnf.d/tripleo.cnf')
+#
+# [*mysql_read_default_group*]
+#   (Optional) Name of the ini section to be passed to pymysql connection strings
+#   Defaults to hiera('tripleo::profile::base:database::mysql::read_default_group', 'tripleo')
+#
+# [*mysql_client_bind_address*]
+#   (Optional) Client IP address of the host that will be written in the mysql_read_default_file
+#   Defaults to hiera('tripleo::profile::base:database::mysql::client_bind_address', undef)
+#
+# [*step*]
+#   (Optional) The current step in deployment. See tripleo-heat-templates
+#   for more details.
+#   Defaults to hiera('step')
+#
+class tripleo::profile::base::database::mysql::client (
+  $mysql_read_default_file   = hiera('tripleo::profile::base:database::mysql::read_default_file', '/etc/my.cnf.d/tripleo.cnf'),
+  $mysql_read_default_group  = hiera('tripleo::profile::base:database::mysql::read_default_group', 'tripleo'),
+  $mysql_client_bind_address = hiera('tripleo::profile::base:database::mysql::client_bind_address', undef),
+  $step = hiera('step'),
+) {
+  if $step >= 1 {
+    # If the folder /etc/my.cnf.d does not exist (e.g. if mariadb is not
+    # present in the base image but installed as a package afterwards),
+    # create it. We do not want to touch the permissions in case it already
+    # exists due to the mariadb server package being pre-installed
+    # Note: We use exec instead of file in the case that the mysql class is
+    # included on this node as well (we'd get duplicate declaration in such a
+    # situation when using file)
+    if $mysql_client_bind_address {
+      $changes = [
+        "set ${mysql_read_default_group}/bind-address '${mysql_client_bind_address}'"
+      ]
+    } else {
+      $changes = [
+        "rm ${mysql_read_default_group}/bind-address"
+      ]
+    }
+    exec { 'directory-create-etc-my.cnf.d':
+      command => 'mkdir -p /etc/my.cnf.d',
+      path    => ['/usr/bin', '/usr/sbin', '/bin', '/sbin'],
+    } ->
+    # Create /etc/my.cnf.d/tripleo.cnf with the [tripleo]bind-address=<IP of the node in the mysql network>
+    augeas { 'mysql-bind-address':
+      incl    => $mysql_read_default_file,
+      lens    => 'Puppet.lns',
+      changes => $changes,
+    }
+  }
+}