vars: Install qpress only when galera_xtrabackup_compression is true

The qpress library is only needed for xtrabackup compression. The
compression only occurs when a new node is joining the cluster
which shouldn't happen very often. The variable is set to true only
when the architecture is x86_64 since that's the only arch that's
supported by the upstream repository and CentOS and Ubuntu do not
provide qpress in the downstream distributions at all.

Change-Id: Iae8b5d0e0998c85ee453efc6620940c80243540e

defaults/main.yml

@@ -114,8 +114,8 @@ galera_wsrep_provider_options:
 galera_wsrep_sst_auth_user: "root"
 galera_wsrep_sst_auth_password: "{{ galera_root_password  }}"
 
-# Enable compression of backups
-galera_xtrabackup_compression: true
+# Enable compression of backups. Qpress is only availabe for x86_64
+galera_xtrabackup_compression: "{{ (ansible_architecture == 'x86_64') | ternary(true, false) }}"
 # xtrabackup parallel/compression/sync threads
 galera_xtrabackup_threads: 4
 

tasks/galera_install.yml

@@ -76,6 +76,13 @@
     name: "{{ galera_server_mariadb_distro_packages_remove | default([]) }}"
     state: absent
 
+- name: Fail if compression is enabled on unsupported architecture
+  fail:
+    msg: "qpress compression is only available on x86_64 architectures"
+  when:
+    - galera_xtrabackup_compression | bool
+    - ansible_architecture != 'x86_64'
+
 - include: "galera_install_{{ ansible_pkg_mgr }}.yml"
 
 - name: Install pip packages

templates/cluster.cnf.j2

@@ -49,7 +49,7 @@ wsrep_retry_autocommit = {{ galera_wsrep_retry_autocommit }}
 [xtrabackup]
 {% if galera_xtrabackup_compression | bool %}
 compress
+compress-threads = {{ galera_xtrabackup_threads }}
 {% endif %}
 parallel = {{ galera_xtrabackup_threads }}
-compress-threads = {{ galera_xtrabackup_threads }}
 rebuild-threads = {{ galera_xtrabackup_threads }}

vars/redhat-7.yml

@@ -45,8 +45,6 @@ galera_server_mariadb_distro_packages:
   - which
   - "{{ galera_mariadb_server_package }}"
   - MariaDB-shared
-  - percona-xtrabackup
-  - percona-toolkit
   - rsync
   - socat
 
@@ -56,6 +54,7 @@ galera_server_mariadb_distro_packages_remove:
   - mariadb-config
   - mariadb-server
   - mariadb-libs
+  - percona-xtrabackup
 
 # The packages to uninstall during an upgrade from a previous version
 galera_server_upgrade_packages_remove:
@@ -77,8 +76,9 @@ _galera_percona_xtrabackup_repo:
   state: "present"
 
 galera_server_percona_distro_packages:
-  - qpress
+  - percona-toolkit
   - percona-xtrabackup
+  - "{{ (galera_xtrabackup_compression | bool) | ternary('qpress', '') }}"
 
 percona_arch_url:
   x86_64: "https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.4.8/binary/redhat/7/x86_64/percona-xtrabackup-24-2.4.8-1.el7.x86_64.rpm"

vars/suse-42.yml

@@ -68,9 +68,9 @@ _galera_repo:
   gpgkey: "https://yum.mariadb.org/RPM-GPG-KEY-MariaDB"
 
 galera_server_percona_distro_packages:
-  - qpress
   - percona-toolkit
   - percona-xtrabackup
+  - "{{ (galera_xtrabackup_compression | bool) | ternary('qpress', '') }}"
 
 galera_wsrep_provider: "/usr/lib64/galera/libgalera_smm.so"
 

vars/ubuntu-16.04.yml

@@ -82,8 +82,9 @@ galera_debconf_items:
     vtype: "string"
 
 galera_server_percona_distro_packages:
-  - qpress
+  - percona-toolkit
   - percona-xtrabackup
+  - "{{ (galera_xtrabackup_compression | bool) | ternary('qpress', '') }}"
 
 percona_arch_url:
   x86_64: "https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.4.8/binary/debian/xenial/x86_64/percona-xtrabackup-24_2.4.8-1.xenial_amd64.deb"