2.6. Allowing Read-Only Access to the History Database
To allow access to the history database without allowing edits, you must create a read-only PostgreSQL user that can log in to and read from the ovirt_engine_history
database. This procedure must be executed on the system on which the history database is installed.
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
- Exit the postgres user shell by pressing Ctrl+d.
Add the following lines for the newly created user to
/var/opt/rh/rh-postgresql10/lib/pgsql/data/pg_hba.conf
preceding the line beginninglocal 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=>
-
To exit the
ovirt_engine_history
database, enter\q
.
The read-only user’s SELECT
statements against tables and views in the ovirt_engine_history
database succeed, while modifications fail.