Device server takes 10 s to start when a local interface address has no reverse DNS answer

Hi folks,

Well the title says what the problem is.

On my machine it took 10s for a very simple Tango server to start.

The problem was caused by a network interface that has no reverse DNS answer

(docker0 here): Tango looks up every local address at startup and waits out

the full 10s resolver timeout on that one.

I had AI generate a script to reproduce it with a dummy pyTango server and

a patched `getnameinfo()`:

git clone https://gitlab.esrf.fr/denolf/tango-startup-dns.git

cd tango-startup-dns

./reproduce.sh

Details in READE.md (obviously all AI).

Cheers,

Wout