docker - (13) Permission denied: AH00957: FCGI: attempt to connect

Now here is my next problem with docker:

[Fri Jan 31 23:49:33.878974 2020] [proxy:error] [pid 6:tid 140048130087712] (13)Permission denied: AH00957: FCGI: attempt to connect to [fd00:cafe:d1ce::2]:9090 (fd00:cafe:d1ce::2) failed 
[Fri Jan 31 23:49:33.879029 2020] [proxy_fcgi:error] [pid 6:tid 140048130087712] [client fd00:cafe:d1ce::1:58820] AH01079: failed to make connection to backend: fd00:cafe:d1ce::2

For some security reasons I configured my "daemon.json" that the namespace is switched to another user (userns-remap).

The container where the apache daemon is running is an alpine linux. This container proxies the php scripts to another container which runs fastcgi. I know that ping could be executed normally if I install the package iputils (reference: Can't ping (permission denied)).

Now my question is: Which package is or which permissions are required to solve that problem?

Solution 1:

Ok now I could resolve my problem by myself. It was so simple... The cause was my local host firewall which was running. After I deactivate this the connection could be established successfully.