KeyError: 'db_name': Ranger KMS server install on Ambari2.7.3

KeyError: 'db_name': Ranger KMS server install on Ambari2.7.3 

Hadoop Installation fails installing Ranger KMS server and subsequently the cluster installation fails. It gives following error:

Please run 'ambari-server setup --jdbc-db={db_name} --jdbc-driver={path_to_jdbc} on server host.'".format(params.db_flavor, params.jdk_location)
KeyError: 'db_name'

This is a database connection issue. First Impression is that we haven't set the database for rangerkms. But their could be different issues which might be causing this situation. Let's look into that:

Install MySQL Connector:

Check MySQL connector is installed or not. If not Install it.

yum install mysql-connector-java -y

Setup JDBC Driver:

Setup the jdbc-driver for ambari-server.

ambari-server setup --jdbc-db={db_name} --jdbc-driver={path_to_jdbc}

Example:

ambari-server setup --jdbc-db=mysql --jdbc-driver=/usr/share/java/mysql-connector-java.jar

Login to MySQL:

mysql -uroot -p{root_password}

Create Database for rangerkms.

create database rangerkms;

Create "rangerkms" User:

create user 'rangerkms'@'localhost' identified by '{rangerkms_password}';

Give Following  permissions on "rangerkms" database for "rangerkms" user.

grant all privileges on rangerkms.* to 'rangerkms'@'localhost';
grant all privileges on rangerkms.* to 'rangerkms'@'%';
grant all privileges on rangerkms.* to 'rangerkms'@'{DB_HOST}' identified by '{rangerkms_password}';
grant all privileges on rangerkms.* to 'rangerkms'@'{DB_HOST}' with grant option;
grant all privileges on rangerkms.* to 'rangerkms'@'%' with grant option;
flush privileges;
quit;