Configuring PostgreSQL for Ranger

On the PostgreSQL host, install the applicable PostgreSQL connector.
RHEL/CentOS/Oracle Linux
```
yum install postgresql-jdbc*
```
SLES
```
zypper install -y postgresql-jdbc
```
Confirm that the .jar file is in the Java share directory.
```
ls /usr/share/java/postgresql-jdbc.jar
```
Change the access mode of the .jar file to 644.
```
chmod 644 /usr/share/java/postgresql-jdbc.jar
```
The PostgreSQL database administrator should be used to create the Ranger databases.
The following series of commands could be used to create the rangerdba user and grant it adequate privileges.
```
echo "CREATE DATABASE $dbname;" | sudo -u $postgres psql -U $postgres
echo "CREATE USER $rangerdba WITH PASSWORD '$passwd';" | sudo -u $postgres psql -U $postgres
echo "GRANT ALL PRIVILEGES ON DATABASE $dbname TO $rangerdba;" | sudo -u $postgres psql -U $postgres 
```
Where:
- $postgres is the Postgres user.
- $dbname is the name of your PostgreSQL database
- $passwd is the password for your Ranger Admin user
- $rangerdba is the username for your Ranger Admin user
Use the following command format to set the jdbc/driver/path based on the location of the PostgreSQL JDBC driver .jar file. This command must be run on the server where Ambari server is installed.
```
ambari-server setup --jdbc-db={database-type} --jdbc-driver={/jdbc/driver/path}
```
For example:
```
ambari-server setup --jdbc-db=postgres --jdbc-driver=/usr/share/java/postgresql-jdbc.jar
```

Run the following command:

export HADOOP_CLASSPATH=${HADOOP_CLASSPATH}:${JAVA_JDBC_LIBS}:/connector jar path

Add Allow Access details for Ranger users:
- (Optional) Use the following command to find the location of postgresql.conf and pg_hba.conf:
```
echo "SHOW config_file;" | sudo -u $postgres psql -U $postgres
```
- change listen_addresses='localhost' to listen_addresses='*' ('*' = any) to listen from all IPs in postgresql.conf.
- Add the Ranger Admin user to the appropriate line in the pg_hba.conf file, the following provides an example:
After editing the pg_hba.conf file, run the following command to refresh the PostgreSQL database configuration:
```
sudo -u postgres /usr/bin/pg_ctl -D $PGDATA reload
```
For example, if the pg_hba.conf file is located in the /var/lib/pgsql/data directory, the value of $PGDATA is /var/lib/pgsql/data.