Receptor sometimes listens on random port

[Ichimonji10]

If receptor is started and no --listen flag is passed, it will listen on *:8888. However, if told to listen on receptor://127.0.0.1, then it will listen on a random port. This behaviour is inconsistent, and at odds with receptor's documented default of listening on port 8888.

--listen absent:

$ poetry run receptor --data-dir="$(mktemp --directory)" node
$ lsof -Pnp 12264 | grep LISTEN
python  12264 ichimonji10    6u     IPv4             254934      0t0      TCP *:8888 (LISTEN)

--listen present:

$ poetry run receptor --data-dir="$(mktemp --directory)" node --listen='receptor://127.0.0.1'
$ lsof -Pnp 11713 | grep LISTEN
python  11713 ichimonji10    6u     IPv4             258329      0t0      TCP 127.0.0.1:39235 (LISTEN)

[matburt]

It looks like it picks a random unassigned port to listen on, which is probably not what you want to happen here.

[Ichimonji10]

My concerns are:

• The receptor docs indicate that port 8888 will be used as the default port, and this is a case that violates that rule.
• There's an inconsistency in the port-selection logic.

Randomly picking a port could be fine (I'd appreciate that functionality when writing automated tests!), but that should be done deliberately.

[ghjm]

@Ichimonji10 This is fixed. It now listens on predictable default ports if you don't specify a port.

[Ichimonji10]

Fixed.

$ poetry run receptor --data-dir="$(mktemp --directory)" node
$ lsof -Pnp 11807 | grep LISTEN
python  11807 ichimonji10    6u     IPv4            1048528      0t0      TCP *:8888 (LISTEN)

$ poetry run receptor --data-dir="$(mktemp --directory)" node --listen='receptor://127.0.0.1'
$ lsof -Pnp 11900 | grep LISTEN
python  11900 ichimonji10    6u     IPv4            1055054      0t0      TCP 127.0.0.1:8888 (LISTEN)