Editing the pg_hba.conf file on a PostgreSQL database server so that a specific (other) server will be able to connect to the PostgreSQL database server

Editing the pg_hba.conf file on a postgresql database server so that a specific (other) server will be able to connect to the postgresql database server.

Example: Say I have a server where all of my postgresql databases are running and I have an application on another server that needs to access a database from the database server. To make this possible I need to edit the pg_hba.conf file to allow access to the application server.

Please follow the steps below for enabling this

1. Make sure your using the CLI
2. First step is to take a backup of the pg_hba.conf file so that if you mess up you’ll have a backup to restore.
   
   The pg_hba.conf file is stored in the following directory ‘/var/lig/pgsql/data‘

   Excecute the command below in order to take a backup

   sudo tar cvf /var/tmp/pg_hbaConf_backup.tar /var/lib/pgsql/data/pg_hba.conf

   By using the tar archive you are preserving the permissions and directories of the files and directories that got compressed.

3. To restore the pg_hba.conf file execute the commands below

   cd /var/lib/pgsql/data/
   
   sudo tar xvf /var/tmp/pg_hbaConf_backup.tar

4. Now we need to edit the pg_hda.conf file as the commands below illustrate

   sudo echo '#SERVER 10.0.26.11 will be able to access the postgres database' 
   
   sudo echo 'host    all         all         10.0.26.11         255.255.255.255   trust' >> /var/lib/pgsql/data/pg_hba.conf

   This code will be appended to the pg_hba.conf file. First we add a comment to explain why the server should have access and then the actual command. To edit the newly inserted lines, use the VIM editor or any other editor to edit the pg_hda.conf file.

5. In order for the change to take effect restart the postgresql database by using the command below.
   {codecitation type: bash}sudo service postgresql restart{/codecitation}
6. Locate the postgresql.conf located in /var/lib/pgsql/data/ and change or add the line below. By default postgresql listens on localhost.

   listen_addresses = '*'