Postgres unclear error message for test connection

[OnkarVO7]

Postgres test connection gives below error when postgres is running locally and OM is running on docker

Describe the task
Improve the error message to point exactly what the error is and show the networking issue
The issue is resolved by following the steps here and putting the hostport as ip_address:5432

[pmbrull]

the error is HTTP/1.1 header parser received no bytes.

We are getting that in a quite specific scenario:

• we point to a known URL (it does not get raised if we go, for example, to random:9876)
• the url does not allow the connection of the driver

For example, in a testing setting in OM, we can reproduce the error if we add the Postgres host as ingestion:8080 (where Airflow runs), which clearly won't respond properly to the JDCB connection.

Then, Airflow receives the POST, starts trying to connect and does not send anything back to the OM client, which raises the HTTP/1.1 header parser received no bytes