Port is already in used, but the program did not panic.

[jianlong0808]

Bug report:

A known issue affects port 4002 (metrics); it is unclear whether other ports are susceptible to the same problem. Ideally, the program should trigger a panic immediately upon detecting that a port is already in use.

Environment:

Dragonfly version:
dragonflyoss/client:v1.2.15
dragonflyoss/dfinit:v1.2.15
OS: Linux
Kernel (e.g. uname -a): 5.10.134-17.an8.x86_64
CRI: containerd github.com/containerd/containerd v1.6.24 61f9fd88f79f081d64d6fa3bb1a0dc71ec870523