** Superset testing
   1. Create sample database:
      1. kubectl exec -it pod/<superset pod> -- /bin/bash
         - Command: kubectl -n superset get pods
         - Pod name looks like: superset-54fd4c9b66-vb2xt
      2. PGPASSWORD=superset psql -U superset -h <superset-postgres-ip>
         - CREATE DATABASE testDB;
         - \c testDB;
         - CREATE TABLE data(id VARCHAR, num INT);
         - INSERT INTO data VALUES('a', 5);
         - INSERT INTO data VALUES('b', 2);
         - INSERT INTO data VALUES('c', 6);
         - exit
      3. exit
   2. Open Superset URL: kubectl get svc | grep -w superset[^-]
   3. Login details:
      - User: admin
      - Password: admin
   4. Click on Settings at top-right:
      - Select Database Connections
   5. Select Data -> Connect database:
      - Select PostgreSQL
      - Hostname: <IP address of superset-postgresql service>
      - Port: 5432
      - Database name: testDB
      - Username: superset
      - Password: superset
      - DisplayName: PostgreSQL
      - Click on "Connect"
      - Click on "Finish"
   6. Click on "+" button on top-right:
      - Select Data -> Create dataset
      - Database name: PostgreSQL
      - Schema: public
      - Select "data"
      - Click on "Create dataset and create chart"
      - Select Bar Chart
      - Click on "Create new chart"
      - Click on Query -> Metrics
        - Select "SIMPLE" tab
        - Select "num" column
        - Select COUNT as AGGREGATE
      - Click on Dimensions
        - Select SIMPLE tab
        - Select "id" column
      - Click on Create chart
   7. The right side display should show a bar chart.