Docker容器間通信與外網通信的操作

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一 容器間通信

1.容器的網絡共享

處於這個模式下的docker容器會共享一個網絡棧，這樣兩個容器之間可以使用localhost高效快速通信。

使用於web服務器與應用服務器之間的通信。

##清空實驗環境
[root@server1 ~]# docker ps -a
CONTAINER ID    IMAGE        COMMAND       CREATED       STATUS       PORTS        NAMES
 
##默認網絡創建容器
[root@server1 ~]# docker run -it --name vm1 ubuntu
root@b1a2a90f98a5:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
368: eth0@if369: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
  link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
  inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
    valid_lft forever preferred_lft forever
root@b1a2a90f98a5:/# [root@server1 ~]# 
 
##container創建與vm1 網絡共享的vm2
[root@server1 ~]# docker run -it --name vm2 --network container:vm1 ubuntu
root@b1a2a90f98a5:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
368: eth0@if369: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
  link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
  inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
    valid_lft forever preferred_lft forever
root@b1a2a90f98a5:/#

2.–link方式

##清空鏡像
[root@server1 ~]# docker rm -f vm1
vm1
[root@server1 ~]# docker rm -f vm2
vm2
[root@server1 ~]# docker ps -a
CONTAINER ID    IMAGE        COMMAND       CREATED       STATUS       PORTS        NAMES
 
##默認網絡創建vm1
[root@server1 ~]# docker run -it --name vm1 ubuntu
root@68e56c57a9a0:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
370: eth0@if371: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
  link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
  inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
    valid_lft forever preferred_lft forever
root@68e56c57a9a0:/# [root@server1 ~]#
 
##--link方式創建vm1子網的容器vm2
[root@server1 ~]# docker run -it --name vm2 --link vm1:web ubuntu
root@61267851b484:/# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
  link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
372: eth0@if373: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
  link/ether 02:42:ac:11:00:03 brd ff:ff:ff:ff:ff:ff
  inet 172.17.0.3/16 brd 172.17.255.255 scope global eth0    ##ip與vm1同網段，遞增
    valid_lft forever preferred_lft forever
 
##解析文件中含有vm1 的ip 與別名等信息
root@61267851b484:/# cat /etc/hosts
127.0.0.1 localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.2 web 68e56c57a9a0 vm1
172.17.0.3 61267851b484
root@61267851b484:/# ^C
root@61267851b484:/#

–link

更新hosts文件

link容器的變量也復制過來

root@61267851b484:/# env
HOSTNAME=61267851b484
TERM=xterm
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arj=01;31:*.taz=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lz=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36:
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
PWD=/
SHLVL=1
HOME=/root
WEB_NAME=/vm2/web
LESSOPEN=| /usr/bin/lesspipe %s
LESSCLOSE=/usr/bin/lesspipe %s %s
_=/usr/bin/env
root@61267851b484:/#

容器停止 ip將釋放掉，開啟後重新獲取其他ip，link的容器自動更新hosts文件

二 容器與外網間的通信

查看當前iptable的nat表火墻策略

[root@server1 ~]# iptables -t nat -nL
Chain PREROUTING (policy ACCEPT)
target   prot opt source        destination     
DOCKER   all -- 0.0.0.0/0      0.0.0.0/0      ADDRTYPE match dst-type LOCAL
 
Chain INPUT (policy ACCEPT)
target   prot opt source        destination     
 
Chain OUTPUT (policy ACCEPT)
target   prot opt source        destination     
DOCKER   all -- 0.0.0.0/0      !127.0.0.0/8     ADDRTYPE match dst-type LOCAL
 
Chain POSTROUTING (policy ACCEPT)
target   prot opt source        destination     
MASQUERADE all -- 172.26.0.0/24    0.0.0.0/0      
MASQUERADE all -- 172.20.0.0/16    0.0.0.0/0      
MASQUERADE all -- 172.18.0.0/16    0.0.0.0/0      
MASQUERADE all -- 172.17.0.0/16    0.0.0.0/0      
 
Chain DOCKER (2 references)
target   prot opt source        destination     
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
RETURN   all -- 0.0.0.0/0      0.0.0.0/0  
##創建nginx容器，並映射端口
[root@server1 ~]# docker run -d --name nginx -p 80:80 nginx
cfefe6420cfe60c46cb7a050c142af7eff86fa6d687c3577077a5b4e2c8b961c
 
##開啟80端口
[root@server1 ~]# docker port nginx 
80/tcp -> 0.0.0.0:80
 
[root@server1 ~]# netstat -antlp | grep 80
tcp6    0   0 :::80          :::*          LISTEN   27094/docker-proxy 
[root@server1 ~]# iptables -t nat -nL
Chain PREROUTING (policy ACCEPT)
target   prot opt source        destination     
DOCKER   all -- 0.0.0.0/0      0.0.0.0/0      ADDRTYPE match dst-type LOCAL
 
Chain INPUT (policy ACCEPT)
target   prot opt source        destination     
 
Chain OUTPUT (policy ACCEPT)
target   prot opt source        destination     
DOCKER   all -- 0.0.0.0/0      !127.0.0.0/8     ADDRTYPE match dst-type LOCAL
 
Chain POSTROUTING (policy ACCEPT)
target   prot opt source        destination     
MASQUERADE all -- 172.26.0.0/24    0.0.0.0/0      
MASQUERADE all -- 172.20.0.0/16    0.0.0.0/0      
MASQUERADE all -- 172.18.0.0/16    0.0.0.0/0      
MASQUERADE all -- 172.17.0.0/16    0.0.0.0/0      
MASQUERADE tcp -- 172.17.0.2      172.17.0.2      tcp dpt:80
 
Chain DOCKER (2 references)
target   prot opt source        destination     
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
RETURN   all -- 0.0.0.0/0      0.0.0.0/0      
DNAT    tcp -- 0.0.0.0/0      0.0.0.0/0      tcp dpt:80 to:172.17.0.2:80
[root@server1 ~]#

以上為個人經驗，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。如有錯誤或未考慮完全的地方，望不吝賜教。

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