docker 容器内服务随容器自动启动

背景

使用docker运行带有nginx服务的容器。容器启动后，每次都需要手动进入容器内启动nginx服务。修改容器内./bashrc文件，让nginx服务随容器自动启动。

容器启动和Linux系统一样，都会随系统启动加载~/.bashrc，所以修改此文件，加入服务启动项。

准备工作

• 使用原nginx-sj: latest镜像文件运行一个容器
  nginx-sj: latest 是我之前使用，已修改的官方nginx镜像文件。

[root@centos7-10 ~]# docker run -itd nginx-sj:latest /bin/bash
root@4eb5280856a3:/# 

• 查看用户目录下.bashrc文件

root@4eb5280856a3:~# pwd
/root
root@4eb5280856a3:~# ls -a
.  ..  .bash_history  .bashrc  .profile  .viminfo

方案一，直接修改.bashrc文件（简单粗暴）

• 直接将服务启动命名写入.bashrc文件，见下

root@4eb5280856a3:~# vim /root/.bashrc

# ~/.bashrc: executed by bash(1) for non-login shells.

# Note: PS1 and umask are already set in /etc/profile. You should not
# need this unless you want different defaults for root.
# PS1='${debian_chroot:+($debian_chroot)}\h:\w\$ '
# umask 022

# You may uncomment the following lines if you want 'ls' to be colorized:
# export LS_OPTIONS='--color=auto'
# eval "$(dircolors)"
# alias ls='ls $LS_OPTIONS'
# alias ll='ls $LS_OPTIONS -l'
# alias l='ls $LS_OPTIONS -lA'
#
# Some more alias to avoid making mistakes:
# alias rm='rm -i'
# alias cp='cp -i'
# alias mv='mv -i'

############################################
# start nginx 
if [ -f /etc/init.d/nginx ]; then
        /etc/init.d/nginx start
fi

方案二，编写启动脚本加入.bashrc文件（文明一点）

• 编辑一个start_nginx.sh文件

root@4eb5280856a3:/# vim /root/start_nginx.sh

• 写入以下内容，并保存

#!/bin/bash

service nginx start 
#service mysql start    //也可以添加其它服务

• 添加start_nginx.sh脚本执行权限

root@4eb5280856a3:/# chmod +x /root/start_nginx.sh

• 将启动脚本写入.bashrc文件

root@4eb5280856a3:~# vim /root/.bashrc

# ~/.bashrc: executed by bash(1) for non-login shells.

# Note: PS1 and umask are already set in /etc/profile. You should not
# need this unless you want different defaults for root.
# PS1='${debian_chroot:+($debian_chroot)}\h:\w\$ '
# umask 022

# You may uncomment the following lines if you want 'ls' to be colorized:
# export LS_OPTIONS='--color=auto'
# eval "$(dircolors)"
# alias ls='ls $LS_OPTIONS'
# alias ll='ls $LS_OPTIONS -l'
# alias l='ls $LS_OPTIONS -lA'
#
# Some more alias to avoid making mistakes:
# alias rm='rm -i'
# alias cp='cp -i'
# alias mv='mv -i'

############################################
# start nginx 
if [ -f /root/start_nginx.sh ]; then
        /root/start_nginx.sh
fi

制作nginx服务自启动镜像

• 将当前容器（4eb5280856a3）导出成文件nginx-sj_20240222.tar

root@4eb5280856a3:~# exit
exit
[root@centos7-10 ~]# docker ps -a
CONTAINER ID   IMAGE             COMMAND       CREATED          STATUS          PORTS     NAMES
4eb5280856a3   nginx-sj:latest   "/bin/bash"   32 minutes ago   Up 30 minutes             vibrant_mcnulty
[root@centos7-10 ~]# docker export -o nginx-sj_20240222.tar 4eb5280856a3
[root@centos7-10 ~]#

• 删除当前容器（4eb5280856a3）

[root@centos7-10 ~]# docker ps -a
CONTAINER ID   IMAGE             COMMAND       CREATED          STATUS          PORTS     NAMES
4eb5280856a3   nginx-sj:latest   "/bin/bash"   34 minutes ago   Up 32 minutes             vibrant_mcnulty
[root@centos7-10 ~]# docker stop 4eb5280856a3
4eb5280856a3
[root@centos7-10 ~]# docker container prune
WARNING! This will remove all stopped containers.
Are you sure you want to continue? [y/N] y
Deleted Containers:
4eb5280856a32b83046e8e3be0393028a1a3f328887a11c0ccff15384660f86e

Total reclaimed space: 7.293kB
[root@centos7-10 ~]# 

• 删除旧nginx-sj:latest镜像

[root@centos7-10 ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED             SIZE
nginx-sj     latest    3e97da40406a   About an hour ago   216MB
ubuntu22     latest    caac235feb32   About an hour ago   338MB
busybox      latest    beae173ccac6   2 years ago         1.24MB
redis        latest    7614ae9453d1   2 years ago         113MB
[root@centos7-10 ~]# docker rmi nginx-sj:latest 
Untagged: nginx-sj:latest
Deleted: sha256:3e97da40406a0daaa4d8c0d948b4c3a8a3d099b3aadb0d9fe8a2be4389bd52e6
[root@centos7-10 ~]# 

• 导入创建新nginx-sj: latest镜像，新镜像ID：283bb24f8ff4

[root@centos7-10 ~]# docker import nginx-sj_20240222.tar nginx-sj:latest
sha256:283bb24f8ff40c67a5ff9d33386847182567f688d7b1b4b109c17054e661b947
[root@centos7-10 ~]# docker images -a nginx-sj:latest 
REPOSITORY   TAG       IMAGE ID       CREATED              SIZE
nginx-sj     latest    283bb24f8ff4   About a minute ago   216MB
[root@centos7-10 ~]# 

测试新镜像，nginx服务随容器自动启动

• 启动容器，宿主机发布端口：9090，容器内服务端口：80

[root@centos7-10 ~]# docker run -itd --rm  -p 9090:80 nginx-sj:latest /bin/bash
562e64af48bbb26f95f3bf3fd01a3550898ca05292f8d95b9bf604c2000d2953
CONTAINER ID   IMAGE             COMMAND       CREATED         STATUS         PORTS                                   NAMES
562e64af48bb   nginx-sj:latest   "/bin/bash"   3 minutes ago   Up 3 minutes   0.0.0.0:9090->80/tcp, :::9090->80/tcp   nervous_golick
[root@centos7-10 ~]# 

• 宿主机已监听端口9090
• 宿主机IP 10.211.55.10

[root@centos7-10 ~]# netstat -ntlp | grep 9090
tcp        0      0 0.0.0.0:9090            0.0.0.0:*               LISTEN      17044/docker-proxy  
tcp6       0      0 :::9090                 :::*                    LISTEN      17050/docker-proxy  
[root@centos7-10 ~]# ip a show enp0s5
2: enp0s5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:1c:42:ae:b6:41 brd ff:ff:ff:ff:ff:ff
    inet 10.211.55.10/24 brd 10.211.55.255 scope global noprefixroute dynamic enp0s5
       valid_lft 1140sec preferred_lft 1140sec
    inet6 fdb2:2c26:f4e4:0:233e:38df:2cbd:cec1/64 scope global noprefixroute dynamic 
       valid_lft 2591662sec preferred_lft 604462sec
    inet6 fe80::7e0c:1902:e1ca:4324/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::567a:248b:5e94:5d19/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

• 访问宿主机HTTP://10.211.55.10:9090，成功！