import psycopg2
import sys


def check():
    # Relying on .pgpass for password
    con = psycopg2.connect('user=monitoring dbname=postgres host=127.0.0.1')
    cur = con.cursor()
    cur.execute("select 'keepalived healthcheck'")
    cur.close()
    con.close()

try:
    check()
    print("ok")
except Exception as e:
    print("not ok")
    print(str(e))
    sys.exit(1)

16:27:45.307006 IP (tos 0x0, ttl 64, id 8123, offset 0, flags [DF], proto TCP (6), length 40)
    localhost.40797 > localhost.postgres: Flags [R], cksum 0x0cca (correct), seq 3830516781, win 0, length 0

2019-04-23 16:27:45.300 CEST process=15615 c= t=0 s=5cbf20e1.3cff [unknown]@127.0.0.1:[unknown] app=[unknown] LOG:  connection received: host=127.0.0.1 port=40797
2019-04-23 16:27:45.304 CEST process=15615 c=authentication t=0 s=5cbf20e1.3cff monitoring@127.0.0.1:postgres app=[unknown] LOG:  connection authorized: user=monitoring database=postgres SSL enabled (protocol=TLSv1.2, cipher=ECDHE-RSA-AES256-GCM-SHA384, compression=off)
2019-04-23 16:27:45.306 CEST process=15615 c=BEGIN t=0 s=5cbf20e1.3cff monitoring@127.0.0.1:postgres app=[unknown] LOG:  duration: 0.095 ms
2019-04-23 16:27:45.306 CEST process=15615 c=SELECT t=0 s=5cbf20e1.3cff monitoring@127.0.0.1:postgres app=[unknown] LOG:  duration: 0.234 ms
2019-04-23 16:27:45.306 CEST process=15615 c=idle in transaction t=0 s=5cbf20e1.3cff monitoring@127.0.0.1:postgres app=[unknown] LOG:  disconnection: session time: 0:00:00.006 user=monitoring database=postgres host=127.0.0.1 port=40797