Foreman 2.x postgres installation path

Anthony_Chevalet · September 1, 2020, 6:07pm

I just realize that postgresql is now installed in /var/opt/rh/rh-postgresql12/lib/pgsql/data/ and it looks to be hard-coded.

Anyone can confirm this?

I know that hard-coding stuff is sometimes required, but I’m surprised to see nothing about this change in the documentation, specially in the upgrade section. The hardware requirement probably need update as well?

3.1.2 Hardware Requirements

The default installation when including Puppet Server will require:
4GB memory
2GB disk space

Same in Katello doc, there is no requirement for postgres but:

The root filesystem needs at least 20 GB of Disk Space

In some (most) cases the old /var/lib/pgsql was a dedicated mount point (with possibly higher disks iops) and the new path ends up on the root disk with just enough space for the OS… As there is no purge by default for audits, tasks etc… (or because some purge does not work depending on the version) the database can grow quickly to a non-negligible size. If it’s installed “silently” on the root disk it might generate some issues in the future. Users should be aware of this.
This is an important information which should be explicitly specified in the documentation, IMHO.

What do you guys think about that?

ekohl · September 2, 2020, 11:14am

I can confirm this. The installer has an automated migration on EL7. This is because we need a newer version than EL7 provides out of the box. That’s why we use the PG12 SCL, which installs to /var/opt. We chose not to modify these paths since they’re also in the SELinux policies.

The actual migration is here:

github.com

theforeman/foreman-installer/blob/develop/hooks/pre/30-el7_upgrade_postgresql.rb

def postgresql_12_upgrade
  start_services(['postgresql'])
  (_name, _owner, _enconding, collate, ctype, _privileges) = `runuser postgres -c 'psql -lt | grep -E "^\s+postgres"'`.chomp.split('|').map(&:strip)
  stop_services

  server_packages = ['rh-postgresql12-postgresql-server']
  if execute_command("rpm -q postgresql-contrib", false, false)
    server_packages << 'rh-postgresql12-postgresql-contrib'
  end
  ensure_packages(server_packages, 'installed')

  execute(%(scl enable rh-postgresql12 "PGSETUP_INITDB_OPTIONS='--lc-collate=#{collate} --lc-ctype=#{ctype} --locale=#{collate}' postgresql-setup --upgrade"))
  ensure_packages(['postgresql-server'], 'absent')
  ensure_packages(['postgresql'], 'absent')
  execute('rm -f /etc/systemd/system/postgresql.service')
  ensure_packages(['rh-postgresql12-syspaths'], 'installed')
end

if local_postgresql? && el7? && foreman_server? && needs_postgresql_scl_upgrade?
  postgresql_12_upgrade

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There are also checks to see if there’s sufficient disk space:

github.com

theforeman/foreman-installer/blob/develop/hooks/pre_validations/30-el7_upgrade_postgresql.rb

def check_postgresql_storage
  # Ensure there is at least 1x /var/lib/pgsql free disk space available on the main filesystem
  current_postgres_dir = '/var/lib/pgsql'
  new_postgres_dir = '/var/opt/rh/rh-postgresql12/lib/pgsql'

  begin
    postgres_size = `du --bytes --summarize #{current_postgres_dir}`.split[0].to_i

    if available_space(new_postgres_dir) < postgres_size
      fail_and_exit "The PostgreSQL upgrade requires at least #{(postgres_size / 1024) / 1024} MB of storage to be available at #{new_postgres_dir}."
    end
  rescue StandardError
    fail_and_exit 'Failed to verify available disk space'
  end
end

def available_space(directory = nil)
  directory = '/' if directory.nil?
  mountpoints = facts[:mountpoints]
  until (mountpoint = mountpoints[directory.to_sym])

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You are right that the docs should mention this. A patch to the docs would be highly appreciated:

github.com

theforeman/theforeman.org/blob/gh-pages/_includes/manuals/nightly/3.1.2_hardware_requirements.md


The hardware requirements for Foreman depend primarily on the number of requests that it will receive, which depends on the number of configuration management clients, web UI activity and other systems using the API.

The default installation when including Puppet Server will require:

* 4GB memory
* 2GB disk space

For a bare minimum installation with few clients and no Puppet master, the requirements are:

* 2GB memory
* 1GB disk space

#### Scaling notes

* The default installation when using Passenger will increase the number of running processes based on the number of simultaneous requests, up to a default maximum of six instances. Each instance will typically require 0.5-1GB of memory, depending on the number of configured plugins.
* When using the Puppet master, consult the requirements outlined in the [Puppet System Requirements](https://docs.puppet.com/puppet/latest/reference/system_requirements.html#hardware) and [Puppet Server System Requirements](https://docs.puppet.com/puppetserver/2.4/install_from_packages.html#system-requirements).
* Disk usage will increase as more data is stored in the database (PostgreSQL by default), mostly for facts and reports. See the [reports cronjob configuration](manuals/{{page.version}}/index.html#3.5.4PuppetReports) to change how they are expired.

I linked the nightly version. I’d recommend to propose changes, get them reviewed and only copy to down to 2.0 once we agree on the changes.

It probably also makes sense to expand the 2.0 release notes:

github.com

theforeman/theforeman.org/blob/gh-pages/_includes/manuals/2.0/1.2_release_notes.md#consolidating-on-postgresql-as-only-supported-database

## Release notes for {{page.version}}

This section will be updated prior to the next release.

### Headline features

#### New sidekiq-based implementation for Dynflow
Foreman now uses Dynflow backed by Sidekiq by default on all supported platforms. This change is described in greater detail in [Upcoming changes to Dynflow](https://community.theforeman.org/t/upcoming-changes-to-dynflow/14926). The original Dynflow executor service (called `dynflowd`) was replaced by `redis` and a set of `dynflow-sidekiq@*` services. This new deployment model should address issues we have seen when restarting the Dynflow executor. It also allows us scale more easily, dedicate workers to specific queues and increase the overall throughput.

#### Consolidating on PostgreSQL as only supported database
In the past, Foreman was trying to be database-agnostic and support multiple databases. That has proven to be very challenging and led to multiple issues due to differences between databases. Starting with Foreman 2.0, we are consolidating on PostgreSQL as the only supported database. RPM based installations will also upgrade PostgreSQL to use version 12 from SCL instead of the default version 9.2 shipped in EL7 repositories.
Katello 3.15, that will be released for compatibility with 2.0, will also start the migration to using the PostgreSQL-based Pulp 3. Initially file and container content types will be switched to Pulp 3 followed by more types in future releases. This means that Katello users will eventually enjoy a single database instead of needing to manage multiple ones (as Pulp 2 is based on MongoDB).
For MySQL users, there are migration instruction in [the 1.24 manual](/manuals/1.24/index.html#3.7MigratingtoPostgreSQL). Note that this migration must be done *prior* to upgrading to Foreman 2.0.

#### Database migrations and seeding no longer run as part of package installation
This will speed up package installation and upgrades. Seeding will now occur on application startup if needed. Migrations will be executed by the installer when it runs. Both can still be manually executed if needed, by running `foreman-rake db:migrate` or `foreman-rake db:seed` respectively. ([#28519](https://projects.theforeman.org/issues/28519))

#### Improved UI for managing authentication sources
External authentication sources can now be assigned to taxonomies using a new UI, similar to how LDAP has been managed. The same page can now be used to manage all authentication sources and see the numbers of users created for each one. ([#21987](https://projects.theforeman.org/issues/21987))

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Anthony_Chevalet · September 2, 2020, 12:12pm

@ekohl Thanks a lot for the clarification and all information.
I’m happy to see that the upgrade step is checking for sufficient disk space so this is just a doc issue.
I’ve just learned that the high quality RedHat documentation will be made available to the community, that’s also a good news!
Again thanks for the great job being made on Foreman/Katello and for all the future improvements, which look amazing!