I just have started using CentOS8 + podman in scope of migration from CentOS7 + docker. The issue is the following:
When firewalld is stopped - DNS works fine inside container:
[root@dev1 ~]# systemctl stop firewalld [root@dev1 ~]# podman run -it alpine ping gmail.com PING gmail.com (172.217.161.133): 56 data bytes 64 bytes from 172.217.161.133: seq=0 ttl=54 time=6.027 ms 64 bytes from 172.217.161.133: seq=1 ttl=54 time=5.892 ms 64 bytes from 172.217.161.133: seq=2 ttl=54 time=5.757 ms ^C --- gmail.com ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max = 5.757/5.892/6.027 msBut once firewalld is launched - DNS stop working inside container, even though network itself (ping) works fine:
[root@dev1 ~]# systemctl start firewalld [root@dev1 ~]# podman run -it alpine ping gmail.com ping: bad address 'gmail.com' [root@dev1 ~]# [root@dev1 ~]# [root@dev1 ~]# podman run -it alpine ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8): 56 data bytes 64 bytes from 8.8.8.8: seq=0 ttl=54 time=4.536 ms 64 bytes from 8.8.8.8: seq=1 ttl=54 time=7.059 ms 64 bytes from 8.8.8.8: seq=2 ttl=54 time=4.924 ms ^C --- 8.8.8.8 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max = 4.536/5.506/7.059 msDNS can work fine in container when it is launched with --net=host param:
[root@dev1 ~]# podman run -it --net=host alpine ping gmail.com PING gmail.com (172.217.161.133): 56 data bytes 64 bytes from 172.217.161.133: seq=0 ttl=55 time=4.981 ms 64 bytes from 172.217.161.133: seq=1 ttl=55 time=5.445 ms 64 bytes from 172.217.161.133: seq=2 ttl=55 time=4.635 ms ^C --- gmail.com ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max = 4.635/5.020/5.445 ms
Any suggestions on how to resolve this issue?
UPDATE: As of 13/Dec/2020 this issue is not reproducible on "CentOS Linux release 8.3.2011".
