No network connectivity to/from Docker CE container on CentOS 8

문제

go: github.com/stretchr/testify@v1.6.1: Get "https://proxy.golang.org/github.com/stretchr/testify/@v/v1.6.1.mod": dial tcp: lookup proxy.golang.org on 8.8.4.4:53: read udp 172.17.0.2:35077->8.8.4.4:53: read: no route to host

원인

해결

docker의 출처 주소 확인

sudo iptables -t nat -nvL POSTROUTING

Chain POSTROUTING (policy ACCEPT 85 packets, 5196 bytes)
pkts bytes target     prot opt in     out     source               destination
3   184 MASQUERADE  all  --  *      !docker0  172.17.0.0/16        0.0.0.0/0

docker 허용 규칙 추가 및 masquerade

firewall-cmd --permanent --zone=public --add-rich-rule='rule family=ipv4 source address=172.17.0.0/16 accept'
firewall-cmd --zone=public --add-masquerade --permanent
firewall-cmd --reload

참조 링크