参考地址： https://stackoverflow.com/questions/40214617/docker-no-route-to-host https://serverfault.com/questions/987686/no-network-connectivity-to-from-docker-ce-container-on-centos-8

问题：

通过docker-compose启动多个服务后，发现服务之间网络请求提示错误：no route to host

  1. Nov 29 09:16:32 172.19.0.1 core[64592]: 2020-11-29T14:16:32Z [ERROR] [/common/utils/utils.go:106]: failed to connect to tcp://postgresql:5432, retry after 2 seconds :dial tcp 172.19.0.3:5432: connect: no route to host
  2. Nov 29 09:16:35 172.19.0.1 core[64592]: 2020-11-29T14:16:35Z [ERROR] [/common/utils/utils.go:106]: failed to connect to tcp://postgresql:5432, retry after 2 seconds :dial tcp 172.19.0.3:5432: connect: no route to host

解决：

查看Docker网络地址

  1. [root@localhost ~]# nmcli
  2. ......
  3. docker0: 已连接 到 docker0
  4.         "docker0"
  5.         bridge, 02:42:C7:FF:5D:E5, 软件, mtu 1500
  6.         inet4 172.17.0.1/16
  7.         route4 172.17.0.0/16
  8.         inet6 fe80::42:c7ff:feff:5de5/64
  9.         route6 fe80::/64
  10.         route6 ff00::/8
  11. ......

添加信任

  1. firewall-cmd --permanent --zone=public --add-rich-rule='rule family=ipv4 source address=172.27.0.0/16 accept'

添加公共区域

  1. # Allows container to container communication, the solution to the problem
  2. firewall-cmd --zone=public --add-masquerade --permanent
  4. # reload the firewall
  5. firewall-cmd --reload

可能的解决方案

  1. nmcli connection modify docker0 connection.zone trusted
  2. systemctl stop NetworkManager.service
  3. firewall-cmd --permanent --zone=trusted --change-interface=docker0
  4. systemctl start NetworkManager.service
  5. nmcli connection modify docker0 connection.zone trusted
  6. systemctl restart docker.service

错误发生环境

  1. [root@localhost ~]# cat /etc/redhat-release
  2. CentOS Linux release 8.2.2004 (Core)
  1. [root@localhost ~]# docker version
  2. Client: Docker Engine - Community
  3.  Version:           19.03.13
  4.  API version:       1.40
  5.  Go version:        go1.13.15
  6.  Git commit:        4484c46d9d
  7.  Built:             Wed Sep 16 17:02:36 2020
  8.  OS/Arch:           linux/amd64
  9.  Experimental:      false
  11. Server: Docker Engine - Community
  12.  Engine:
  13.   Version:          19.03.13
  14.   API version:      1.40 (minimum version 1.12)
  15.   Go version:       go1.13.15
  16.   Git commit:       4484c46d9d
  17.   Built:            Wed Sep 16 17:01:11 2020
  18.   OS/Arch:          linux/amd64
  19.   Experimental:     false
  20.  containerd:
  21.   Version:          1.3.7
  22.   GitCommit:        8fba4e9a7d01810a393d5d25a3621dc101981175
  23.  runc:
  24.   Version:          1.0.0-rc10
  25.   GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
  26.  docker-init:
  27.   Version:          0.18.0
  28.   GitCommit:        fec3683
  1. [root@localhost ~]# docker-compose version
  2. docker-compose version 1.27.4, build 40524192
  3. docker-py version: 4.3.1
  4. CPython version: 3.7.7
  5. OpenSSL version: OpenSSL 1.1.0l  10 Sep 2019