docs: Fix PostgreSQL DSN example [skip ci]

[rc5hack]

Fix DSN example for PostgreSQL db in Readme + fix yaml indentation (2 spaces per level).

[burningalchemist]

Good catch, thank you! 👍

[burningalchemist]

@rc5hack Hold on, it's actually incorrect. targets is a map. In your change indentation broke inheritance and turned named targets into the array items.

What was the original problem with the example?

I'll revert it for now.

[rc5hack]

My fault. Indentation inside of targets: (4 spaces) was correct (2 spaces per level, 2 levels), but between static_configs: and targets: it is redundant (4 spaces, while only 2 needed). It would work as is, but better to be reduced.

This works for me:

jobs:
  - job_name: db_targets
    collectors: [dummy]
    enable_ping: true
    static_configs:
      - targets:
          db-foo: 'postgresql://user:passw0rd@hostname:5432/dummy?sslmode=disable'
          db-bar: 'postgresql://user:passw0rd@other-host:5432/dummy?sslmode=disable'

Original problem is that pg://db1@127.0.0.1:25432/postgres?sslmode=disable DSN has db1 as user and no password, which is uncommon/frustrating, and also uses pg:// scheme instead of postgres://, which is also unusual (but, TIL, is compatible).

[burningalchemist]

Yeah, it works fine since we use dburl dependency, which helps picking the right driver for the chosen protocol - https://github.com/xo/dburl. And there are multiple drivers available for Postgres. Have a look whenever you have some free time. 🙂👍

Other than that, no objections. Do you mind creating one more PR? 🙂