Process

ANSIBLE_LIBRARY=Ansible4IOM/modules/ ANSIBLE_ROLES_PATH=Ansible4IOM/roles/ ansible-playbook -i config-repos/oms-plain/distributed_azure_2.2/inventory Ansible4IOM/processes/reconfigure_pgserver.yml

Steps

The process consists of the following steps:

1. pgserver_configure
   1. Stop/disable service.
   2. Install initial pg_hba.conf in order to allow setting superusers password.
   3. Set default values in postgresql.conf.
   4. Start/enable service (wait for DB to get ready).
   5. Update superusers password.
   6. Install productive pg_hba.conf in order to restrict access as much as possible.
   7. Run post_pgserver_configuration_hook.
   8. Restart service to apply changes.
2. omsdb_initialization
   1. Create/update db user.
   2. Create/update database.

Background Information

The process reconfigure_pgserver updates selected configurations of an already installed PostgreSQL server. Primarily, the process is able to apply changes made to variables defined in roles/pgserver_config/defaults. Please have a look into the according file to get information about which variables might be changed after initial setup and which not.

Additionally, the process reconfigure_pgserver executes the hook post_pgserver_configuration_hook, which allows configuration changes besides predefined variables.

In a second step, the process reconfigure_pgserver reruns the role omsdb_initialization too. This enables to change settings defined in roles/omsdb_initialization/defaults. Please have a look into the according file, to get more information. Finally, the only settings to be changed during process reconfigure_pgserver, are user and password of the IOM database account, which can be controlled by variables is_oms_db_user and is_oms_db_pass (roles/oms_config/defaults).

Examples

Change the Password of the SuperUser

The password of the superuser is defined by variable PGSERVER_SUPERUSER_PASSWD at roles/pgserver_config/defaults. Add this variable to the inventory and give it a new value. Also see Concept - Ansible4IOM Server Configuration Management 1.0 - 1.1.

...
[all:vars]
PGSERVER_SUPERUSER_PASSWD="NewPa22w0r6"
...

Now the process reconfigure_pgserver can be executed.

ANSIBLE_LIBRARY=<path to Ansible4IOM>/modules/ ANSIBLE_ROLES_PATH=<path to Ansible4IOM>/roles/ ansible-playbook -i <path to inventory file> <path to Ansible4IOM>/processes/reconfigure_pgserver.yml

Change Port of Database Server

The port of the database server is defined by the variable PGSERVER_PORT at roles/pgserver_config/defaults. Add this variable to the inventory and give it a new value. According to the separation of components, IOM application servers need to be reconfigured to. Access of application-servers to the database is controlled by the property is.oms.db.hostlist in cluster.properties, which is reflected by variable is_oms_db_hostlist (defined at roles/oms_config/defaults). Hence this variable has to be adapted too. Also see Concept - Ansible4IOM Server Configuration Management 1.0 - 1.1.

...
[all:vars]
PGSERVER_PORT=5433
is_oms_db_hostlist="localhost:5433"
...

Now the process reconfigure_pgserver can be executed. Since IOM settings had to be changed too, the process reconfigure_oms_node needs to be run afterwards.

ANSIBLE_LIBRARY=<path to Ansible4IOM>/modules/ ANSIBLE_ROLES_PATH=<path to Ansible4IOM>/roles/ ansible-playbook -i <path to inventory file> <path to Ansible4IOM>/processes/reconfigure_pgserver.yml
ANSIBLE_LIBRARY=<path to Ansible4IOM>/modules/ ANSIBLE_ROLES_PATH=<path to Ansible4IOM>/roles/ ansible-playbook -i <path to inventory file> <path to Ansible4IOM>/processes/reconfigure_oms_node.yml

Change max_connections Setting in postgresql.conf

To change database server settings besides predefined variables, the hook post_pgserver_configuration_hook has to be implemented. Depending on the scope of the hook (project or installation), the file post_pgserver_configuration_hook.yml has to be stored in the directory global_hooks or installation_hooks. Also see Concept - Ansible4IOM Server Configuration Management 1.0 - 1.1.

It is important to use variables PGSERVER_DATA and PGServerOSUser (see roles/pgserver_config/defaults) for a robust implementation of the hook.

- name: update postgreSQL configuration
  ini_file:
    dest: "{{PGSERVER_DATA}}/postgresql.conf"
    section: ""
    option: "{{item.option}}"
    value: "{{item.value}}"
  with_items:
    - { option: max_connections, value: 500 }
  become: true
  become_user: "{{PGServerOSUser}}"

Now process reconfigure_pgserver can be executed.

ANSIBLE_LIBRARY=<path to Ansible4IOM>/modules/ ANSIBLE_ROLES_PATH=<path to Ansible4IOM>/roles/ ansible-playbook -i <path to inventory file> <path to Ansible4IOM>/processes/reconfigure_pgserver.yml