When deploying Foreman on CentOS 7, you by default get PostgreSQL 9.2 as packaged in CentOS (and RHEL). However PostgreSQL 9.2 is officially EOL upstream and newer versions bring various performance improvements which might benefit the Foreman installation. This post will show how to deploy Foreman with PostgreSQL 9.6 from SoftwareCollections.org.
Given the Foreman Installer will setup everything for us, we really only have to tell the Installer that we want a different version of PostgreSQL, where to find it and how it should be configured.
As the Installer does not have any command line options to configure PostgreSQL, we will have to create a custom-hiera.yaml with the required values.
Under the hood, the Installer is using the puppetlabs-postgresql Puppet module, so that is the source for our customization.
Initially I wanted to override the postgresql::server::* and postgresql::client::* values, as documented in the README.md, however doing so would require overriding many values, as the module generates many variables in postgresql::params based on the values from postgresql::globals.
Instead we will override the values directly in postgresql::globals and let all the other classes inherit our definitions.
Given that packages from SoftwareCollections.org always come with a prefix for almost everything, we’ll have to override the package names, systemd unit names and the data folder.
Luckily, the PostgreSQL 9.6 software collection also contains syspaths packages (rh-postgresql96-postgresql-syspaths, rh-postgresql96-postgresql-server-syspaths, etc), so that we won’t have to worry about scripts expecting /usr/bin/psql or similar to exist (“normal” SCL packages don’t touch /usr/bin and require a scl enable NAME to add the SCL-specific bin folder to your PATH). It also provides a postgresql.service, which is an alias for rh-postgresql96-postgresql.service.
Looking at postgresql::globals and postgresql::params, we come up with the following settings:
postgresql::globals::version: '9.6'
postgresql::globals::client_package_name: rh-postgresql96-postgresql-syspaths
postgresql::globals::server_package_name: rh-postgresql96-postgresql-server-syspaths
postgresql::globals::contrib_package_name: rh-postgresql96-postgresql-contrib-syspaths
postgresql::globals::service_name: postgresql
postgresql::globals::datadir: /var/opt/rh/rh-postgresql96/lib/pgsql/data
postgresql::globals::confdir: /var/opt/rh/rh-postgresql96/lib/pgsql/data
postgresql::globals::bindir: /usr/bin
Just add these lines to /etc/foreman-installer/custom-hiera.yaml before running foreman-installer and we end up with Foreman running against a PostgreSQL 9.6.
There is one small issue with this setup, though. Probably because of PUP-2169 /var/opt/rh/rh-postgresql96/lib/pgsql/data/postgresql.conf is not getting the correct SELinux context when created by Puppet, and thus PostgreSQL fails to start. To fix that you’d need to either run the Installer in permissive mode and relabel the file afterwards (restorecon -Rv /var/opt/rh/rh-postgresql96/lib/pgsql/data/postgresql.conf), or expect the failure, relabel and re-run the installier a second time.
Don’t worry that we see also PostgreSQL 9.2 packages in rpm -qa:
# rpm -qa |grep postgresql
foreman-postgresql-1.16.0-1.el7.noarch
rh-postgresql96-postgresql-9.6.5-1.el7.x86_64
rh-postgresql96-postgresql-libs-9.6.5-1.el7.x86_64
rh-postgresql96-postgresql-syspaths-9.6.5-1.el7.x86_64
rh-postgresql96-postgresql-server-syspaths-9.6.5-1.el7.x86_64
postgresql-libs-9.2.23-3.el7_4.x86_64
rh-postgresql96-runtime-3.0-10.el7.x86_64
rh-postgresql96-postgresql-server-9.6.5-1.el7.x86_64
foreman-postgresql requires tfm-rubygem-pg which is compiled against postgresql-libs, and that’s totally fine, as this is only the client parts for Ruby that are running with an older libpq.
quick setup with forklift
If you just want to try it out, and love forklift as I do, just get a version of forklift with my custom-hiera.yaml PR merged and create a box like this:
$ cat boxes.d/99-local.yaml
---
centos7-foreman-1.16-psql96:
box: centos7
ansible:
playbook: playbooks/foreman.yml
variables:
foreman_repositories_version: 1.16
puppet_repositories_version: 5
selinux_state: permissive
foreman_installer_custom_hiera: |
postgresql::globals::version: '9.6'
postgresql::globals::client_package_name: rh-postgresql96-postgresql-syspaths
postgresql::globals::server_package_name: rh-postgresql96-postgresql-server-syspaths
postgresql::globals::contrib_package_name: rh-postgresql96-postgresql-contrib-syspaths
postgresql::globals::service_name: postgresql
postgresql::globals::datadir: /var/opt/rh/rh-postgresql96/lib/pgsql/data
postgresql::globals::confdir: /var/opt/rh/rh-postgresql96/lib/pgsql/data
postgresql::globals::bindir: /usr/bin
and after a vagrant up centos7-foreman-1.16-psql96 you should have it up and running.
Enjoy!