2.6. Allowing Read-Only Access to the History Database

Enable psql commands:

# su - postgres -c 'scl enable rh-postgresql10 bash'

Create the user to be granted read-only access to the history database:

# psql -U postgres -c "CREATE ROLE username WITH LOGIN ENCRYPTED PASSWORD 'password';" -d ovirt_engine_history

Grant the newly created user permission to connect to the history database:

# psql -U postgres -c "GRANT CONNECT ON DATABASE ovirt_engine_history TO username;"

Grant the newly created user usage of the public schema:

# psql -U postgres -c "GRANT USAGE ON SCHEMA public TO username;" ovirt_engine_history

Generate the rest of the permissions that will be granted to the newly created user and save them to a file:

# psql -U postgres -c "SELECT 'GRANT SELECT ON ' || relname || ' TO username;' FROM pg_class JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace WHERE nspname = 'public' AND relkind IN ('r', 'v');" --pset=tuples_only=on  ovirt_engine_history > grant.sql

Use the file you created in the previous step to grant permissions to the newly created user:

# psql -U postgres -f grant.sql ovirt_engine_history

Remove the file you used to grant permissions to the newly created user:

# rm grant.sql

Add the following lines for the newly created user to /var/opt/rh/rh-postgresql10/lib/pgsql/data/pg_hba.conf preceding the line beginning local all all, as follows:

# TYPE  DATABASE                USER           ADDRESS                 METHOD
host    ovirt_engine_history    username    0.0.0.0/0               md5
host    ovirt_engine_history    username    ::0/0                   md5
local   all             all                                     peer

Reload the PostgreSQL service:

# systemctl reload rh-postgresql10-postgresql

To test the read-only user’s access permissions:

# su - postgres -c 'scl enable rh-postgresql10 -- psql -U username ovirt_engine_history -h localhost'
Password for user username:
psql (9.2.23)
Type "help" for help.

ovirt_engine_history=>