### Purpose
Treat X-Forwarded-For as a comma-separated string to prevent nil IP being returned by the Discovery Server
### Testing
Unit Tests implemented
Testing with a Discovery Client can be done as follows:
```
A simple example to replicate this entails running Discovery with HTTP, use Nginx as a reverse proxy and hardcode (as an example) a list of IPs in the X-Forwarded-For header.
1. Send an Announcement with tcp://0.0.0.0:<some-port>
2. Query the DeviceID
3. Observe the returned IP Address is no longer nil; i.e. `tcp://<nil>:<some-port>`
```
This adds the ability to have multiple concurrent connections to a single device. This is primarily useful when the network has multiple physical links for aggregated bandwidth. A single connection will never see a higher rate than a single link can give, but multiple connections are load-balanced over multiple links.
It is also incidentally useful for older multi-core CPUs, where bandwidth could be limited by the TLS performance of a single CPU core -- using multiple connections achieves concurrency in the required crypto calculations...
Co-authored-by: Simon Frei <freisim93@gmail.com>
Co-authored-by: tomasz1986 <twilczynski@naver.com>
Co-authored-by: bt90 <btom1990@googlemail.com>
refactor: unused parameter should be replaced by underscore
Unused parameters in functions or methods should be replaced with `_`
(underscore) or removed.
Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>
This allows environment overrides for our directories. This is
advantageous because, apart from the obvious, it means we can set it in
the Docker file and not add command line options there. Having the
command line option as we did meant that it was impossible to use the
Docker image for other commands than `serve` (because that is implied
when we see other options on the command line).
The problem was that a statistics/cleanup run is triggered when the
database started and runs concurrently with the test. That cleanup run
removes old entries without valid addresses, and one of the test objects
matched this. The test object would thus randomly be removed in the
middle of the test, causing a failure. This fixes it so the object looks
recent when the cleaner-upper looks, and also uses a RAM database
(faster).