I'm installing a Moodle 3.9 instance on RHEL 8.0 and need to use our company Oracle DB. I have had a schema deployed, and tested that is ready to use, but I cannot get Moodle to connect to it. Moodle only states the connection failed and the config.php file should be checked. I had to build the oci8 module from a PHP package using Oracle instant client, updated the httpd.conf file, and confirmed oci8 module is active with info.php. Below are the versions of the different components I'm working with.
Oracle DB 19c
Moodle config.php database parameters
$CFG->dbtype = 'oci'; // 'pgsql', 'mariadb', 'mysqli', 'sqlsrv' or 'oci'
$CFG->dblibrary = 'native'; // 'native' only at the moment
$CFG->dbhost = 'enged-db-dev1.foo.com'; // eg 'localhost' or 'db.isp.com' or IP
$CFG->dbname = 'engeddev'; // database name, eg moodle
$CFG->dbuser = 'moodle_test'; // your database username
$CFG->dbpass = 'moodle_test'; // your database password
$CFG->prefix = 'md'; // prefix to use for all table names
$CFG->dboptions = array(