Documentation should explain how docker interacts with the database

[lukeshaughnessy]

Steps to Reproduce:

1. Verify database user and password:

psql --host 127.0.0.1 --port 5432 --username postgres_exporter postgres
Password for user postgres_exporter: 
psql (9.5.7)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
Type "help" for help.

postgres=> 

2. Docker run with:

docker run -e DATA_SOURCE_NAME="postgresql://postgres_exporter:password@127.0.0.1:5432/postgres?sslmode=disable" -p 9187:9187 wrouesnel/postgres_exporter

3. Result:

level=info msg="Error opening connection to database (could not parse DATA_SOURCE_NAME): dial tcp 127.0.0.1:5432: getsockopt: connection refused" source="postgres_exporter.go:959" 

[manics]

127.0.0.1 as seen by the postgres_exporter Docker container refers to itself, try using the IP of the system hosting the DB?

[lukeshaughnessy]

Thanks, that was the correct answer. Maybe a note in the docs to specify host ip in the docker run command?

[baryluk]

Maybe just use --net=host.