跟着狂神学Docker（精髓篇）

容器数据卷

什么是容器数据卷

docker的理念回顾

将应用和环境打包成一个镜像！

数据？如果数据都在容器中，那么我们容器删除，数据就会丢失！需求：数据可以持久化

MySQL，容器删除了，删库跑路！需求：MySQL数据可以存储在本地！

容器之间可以有一个数据共享的技术！Docker容器中产生的数据，同步到本地！

这就是卷技术！目录的挂载，将我们容器内的目录，挂载到Linux上面！

总结一句话：容器的持久化和同步操作！容器间也是可以数据共享的！

使用数据卷

方式一 ：直接使用命令挂载 -v

-v, --volume list                    Bind mount a volume

docker run -it -v 主机目录:容器内目录  -p 主机端口:容器内端口
# /home/ceshi：主机home目录下的ceshi文件夹  映射：centos容器中的/home
[root@localhost home]# docker run -it -v /home/ceshi:/home centos /bin/bash
#这时候主机的/home/ceshi文件夹就和容器的/home文件夹关联了,二者可以实现文件或数据同步了
#这里解答一下这不是同步 这是 在磁盘上使用同一个分区物理地址是一个

#新的窗口
#通过 docker inspect 容器id 查看
[root@localhost home]# docker inspect 5b1e64d8bbc0

这里解答一下这不是同步 这是 在磁盘上使用同一个分区物理地址是一个

再来测试！

1、停止容器

2、宿主机修改文件

3、启动容器

4、容器内的数据依旧是同步的

好处：我们以后修改只需要在本地修改即可，容器内会自动同步！

实战：安装MySQL

Docker商店

https://hub.docker.com/

思考：MySQL的数据持久化的问题

# 获取mysql镜像
[root@localhost home]# docker pull mysql:5.7
# 运行容器,需要做数据挂载 #安装启动mysql，需要配置密码的，这是要注意点！
# 参考官网hub 
docker run --name some-mysql -e MYSQL_ROOT_PASSWORD=my-secret-pw -d mysql:tag

#启动我们得
-d 后台运行
-p 端口映射
-v 卷挂载
-e 环境配置
-- name 容器名字
[root@localhost home]#  docker run -d -p 3306:3306 -v /home/mysql/conf:/etc/mysql/conf.d -v /home/mysql/data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 --name mysql01 mysql:5.7

# 启动成功之后，我们在本地使用sqlyog来测试一下
# sqlyog-连接到服务器的3306--和容器内的3306映射 

# 在本地测试创建一个数据库，查看一下我们映射的路径是否ok！

[root@localhost home]# ls
ceshi  huang.java  huangjialin  huang.txt  mylinux  mysql  test.java  testTmp
[root@localhost home]# cd mysql
[root@localhost mysql]# ls
conf  data
[root@localhost mysql]# cd data/
[root@localhost data]# ls
auto.cnf    client-cert.pem  ibdata1      ibtmp1              private_key.pem  server-key.pem
ca-key.pem  client-key.pem   ib_logfile0  mysql               public_key.pem   sys
ca.pem      ib_buffer_pool   ib_logfile1  performance_schema  server-cert.pem

新建数据库

多了test文件

[root@localhost data]# ls
auto.cnf    client-cert.pem  ibdata1      ibtmp1              private_key.pem  server-key.pem
ca-key.pem  client-key.pem   ib_logfile0  mysql               public_key.pem   sys
ca.pem      ib_buffer_pool   ib_logfile1  performance_schema  server-cert.pem  test

假设我们把容器删除

[root@localhost data]# docker rm -f mysql01
mysql01
[root@localhost data]# docker ps
CONTAINER ID   IMAGE     COMMAND       CREATED          STATUS          PORTS     NAMES
5b1e64d8bbc0   centos    "/bin/bash"   56 minutes ago   Up 39 minutes             keen_leavitt
[root@localhost data]# docker ps -a

[root@localhost home]# ls
ceshi  huang.java  huangjialin  huang.txt  mylinux  mysql  test.java  testTmp
[root@localhost home]# cd mysql
[root@localhost mysql]# ls
conf  data
[root@localhost mysql]# cd data/
[root@localhost data]# ls
auto.cnf    client-cert.pem  ibdata1      ibtmp1              private_key.pem  server-key.pem
ca-key.pem  client-key.pem   ib_logfile0  mysql               public_key.pem   sys
ca.pem      ib_buffer_pool   ib_logfile1  performance_schema  server-cert.pem

发现，我们挂载到本地的数据卷依旧没有丢失，这就实现了容器数据持久化功能。

具名和匿名挂载

# 匿名挂载
-v 容器内路径!
[root@localhost home]# docker run -d -P --name nginx01 -v /etc/nginx nginx

# 查看所有的volume(卷)的情况
[root@localhost home]# docker volume ls    
DRIVER              VOLUME NAME # 容器内的卷名(匿名卷挂载)
local               21159a8518abd468728cdbe8594a75b204a10c26be6c36090cde1ee88965f0d0
local               b17f52d38f528893dd5720899f555caf22b31bf50b0680e7c6d5431dbda2802c
         
# 这里发现，这种就是匿名挂载，我们在 -v只写了容器内的路径，没有写容器外的路径！

# 具名挂载 -P:表示随机映射端口
[root@localhost home]# docker run -d -P --name nginx01 -v /etc/nginx nginx
a35688cedc667161695f56bd300c12a6468312558c63a634d136bf8e73db4680

# 查看所有的volume(卷)的情况
[root@localhost home]# docker volume ls
DRIVER    VOLUME NAME
local     8bef6b16668574673c31978a4d05c212609add5b4ca5ea2f09ff8680bdd304a6
local     a564a190808af4cdca228f6a0ea3664dd14e34fee81811ed7fbae39158337141

# 具名挂载
[root@localhost home]# ls
ceshi  huang.java  huangjialin  huang.txt  mylinux  mysql  test.java  testTmp
[root@localhost home]# docker run -d -P --name nginx02 -v juming-nginx:/etc/nginx nginx	#具名挂载
330f5a75c39945c6bed44292925219ed0d8d37adc0b1bc37b37784aae405b520
[root@localhost home]# docker volume ls
DRIVER    VOLUME NAME
local     8bef6b16668574673c31978a4d05c212609add5b4ca5ea2f09ff8680bdd304a6
local     a564a190808af4cdca228f6a0ea3664dd14e34fee81811ed7fbae39158337141
local     juming-nginx	# 具名挂载

# 通过 -v 卷名：查看容器内路径
# 查看一下这个卷
[root@localhost home]# docker volume inspect juming-nginx
[
    {
        "CreatedAt": "2021-04-12T06:53:09-07:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/juming-nginx/_data",
        "Name": "juming-nginx",
        "Options": null,
        "Scope": "local"
    }
]

所有的docker容器内的卷，没有指定目录的情况下都是在**/var/lib/docker/volumes/自定义的卷名/_data**下，
我们通过具名挂载可以方便的找到我们的一个卷,大多数情况在使用的具名挂载

[root@localhost home]# cd /var/lib/docker
[root@localhost docker]# ls
buildkit  containers  image  network  overlay2  plugins  runtimes  swarm  tmp  trust  volumes
[root@localhost docker]# cd volumes/
[root@localhost volumes]# ls
8bef6b16668574673c31978a4d05c212609add5b4ca5ea2f09ff8680bdd304a6  backingFsBlockDev  metadata.db
a564a190808af4cdca228f6a0ea3664dd14e34fee81811ed7fbae39158337141  juming-nginx
[root@localhost volumes]# cd juming-nginx/
[root@localhost juming-nginx]# ls
_data
[root@localhost juming-nginx]# cd _data/
[root@localhost _data]# ls
conf.d  fastcgi_params  koi-utf  koi-win  mime.types  modules  nginx.conf  scgi_params  uwsgi_params  win-utf
[root@localhost _data]# cat nginx.conf 

user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    include /etc/nginx/conf.d/*.conf;
}

如果指定了目录，docker volume ls 是查看不到的。

区分三种挂载方式

# 三种挂载： 匿名挂载、具名挂载、指定路径挂载
-v 容器内路径			#匿名挂载
-v 卷名：容器内路径		  #具名挂载
-v /宿主机路径：容器内路径 #指定路径挂载 docker volume ls 是查看不到的

拓展：

# 通过 -v 容器内路径： ro rw 改变读写权限
ro #readonly 只读
rw #readwrite 可读可写

# 一旦这个设置了容器权限，容器对我们挂载出来的内容就有限定了！
[root@localhost home]# docker run -d -P --name nginx05 -v juming:/etc/nginx:ro nginx
[root@localhost home]# docker run -d -P --name nginx05 -v juming:/etc/nginx:rw nginx

# ro 只要看到ro就说明这个路径只能通过宿主机来操作，容器内部是无法操作！

初始Dockerfile

Dockerfile 就是用来构建docker镜像的构建文件！命令脚本！先体验一下！
通过这个脚本可以生成镜像，镜像是一层一层的，脚本是一个个的命令，每个命令都是一层！

[root@localhost /]# cd /home
[root@localhost home]# ls
ceshi  huang.java  huangjialin  huang.txt  mylinux  mysql  test.java  testTmp
[root@localhost home]# mkdir docker-test-volume
[root@localhost home]# ls
ceshi  docker-test-volume  huang.java  huangjialin  huang.txt  mylinux  mysql  test.java  testTmp
[root@localhost home]# cd docker-test-volume/
[root@localhost docker-test-volume]# pwd
/home/docker-test-volume

#通过这个脚本可以生成镜像
[root@localhost docker-test-volume]# vim dockerfile1	

# 创建一个dockerfile文件，名字可以随便 建议Dockerfile
# 文件中的内容： 指令(大写) + 参数
[root@localhost docker-test-volume]# vim dockerfile1
    FROM centos 					# 当前这个镜像是以centos为基础的

    VOLUME ["volume01","volume02"] 	# 挂载卷的卷目录列表(多个目录)

    CMD echo "-----end-----"		# 输出一下用于测试
    CMD /bin/bash					# 默认走bash控制台

[root@localhost docker-test-volume]# cat dockerfile1 
FROM centos

VOLUME ["volume01","volume02"]

CMD echo "-----end-----"
CMD /bin/bash


# 这里的每个命令，就是镜像的一层！
# 构建出这个镜像 
-f dockerfile1 			# f代表file，指这个当前文件的地址(这里是当前目录下的dockerfile1)
-t caoshipeng/centos 	# t就代表target，指目标目录(注意caoshipeng镜像名前不能加斜杠‘/’)
. 						# 表示生成在当前目录下

[root@localhost docker-test-volume]# docker build -f dockerfile1 -t huangjialin/centos:1.0 .
Sending build context to Docker daemon  2.048kB
Step 1/4 : FROM centos
 ---> 300e315adb2f
Step 2/4 : VOLUME ["volume01","volume02"] 			# 卷名列表
 ---> Running in 2d8ae11d9994
Removing intermediate container 2d8ae11d9994
 ---> 5893b2c78edd
Step 3/4 : CMD echo "-----end-----"					# 输出 脚本命令
 ---> Running in 2483f0e77b68
Removing intermediate container 2483f0e77b68
 ---> 30bf0ad14072
Step 4/4 : CMD /bin/bash
 ---> Running in 8fee073c961b
Removing intermediate container 8fee073c961b
 ---> 74f0e59c6da4
Successfully built 74f0e59c6da4
Successfully tagged huangjialin/centos:1.0

# 查看自己构建的镜像
[root@localhost docker-test-volume]# docker images
REPOSITORY            TAG       IMAGE ID       CREATED              SIZE
huangjialin/centos    1.0       74f0e59c6da4   About a minute ago   209MB

[root@localhost docker-test-volume]# docker run -it 74f0e59c6da4 /bin/bash
[root@0be9ef3e0f75 /]# ls -l
total 0
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 bin -> usr/bin
drwxr-xr-x.   5 root root 360 Apr 12 14:38 dev
drwxr-xr-x.   1 root root  66 Apr 12 14:38 etc
drwxr-xr-x.   2 root root   6 Nov  3 15:22 home
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 lib -> usr/lib
lrwxrwxrwx.   1 root root   9 Nov  3 15:22 lib64 -> usr/lib64
drwx------.   2 root root   6 Dec  4 17:37 lost+found
drwxr-xr-x.   2 root root   6 Nov  3 15:22 media
drwxr-xr-x.   2 root root   6 Nov  3 15:22 mnt
drwxr-xr-x.   2 root root   6 Nov  3 15:22 opt
dr-xr-xr-x. 253 root root   0 Apr 12 14:38 proc
dr-xr-x---.   2 root root 162 Dec  4 17:37 root
drwxr-xr-x.  11 root root 163 Dec  4 17:37 run
lrwxrwxrwx.   1 root root   8 Nov  3 15:22 sbin -> usr/sbin
drwxr-xr-x.   2 root root   6 Nov  3 15:22 srv
dr-xr-xr-x.  13 root root   0 Apr  7 10:09 sys
drwxrwxrwt.   7 root root 145 Dec  4 17:37 tmp
drwxr-xr-x.  12 root root 144 Dec  4 17:37 usr
drwxr-xr-x.  20 root root 262 Dec  4 17:37 var
drwxr-xr-x.   2 root root   6 Apr 12 14:38 volume01
drwxr-xr-x.   2 root root   6 Apr 12 14:38 volume02

这个卷和外部一定有一个同步的目录！

[root@0be9ef3e0f75 /]# exit
exit
[root@localhost docker-test-volume]# docker ps
CONTAINER ID   IMAGE     COMMAND                  CREATED             STATUS             PORTS                   NAMES
330f5a75c399   nginx     "/docker-entrypoint.…"   54 minutes ago      Up 54 minutes      0.0.0.0:49154->80/tcp   nginx02
a35688cedc66   nginx     "/docker-entrypoint.…"   About an hour ago   Up About an hour   0.0.0.0:49153->80/tcp   nginx01
[root@localhost docker-test-volume]# docker run -it 74f0e59c6da4 /bin/bash
[root@f8bd9a180286 /]# cd volume01
[root@f8bd9a180286 volume01]# touch container.txt
[root@f8bd9a180286 volume01]# ls
container.txt

查看一下卷挂载的路径

# docker inspect 容器id
$ docker inspect ca3b45913df5

# 另一个窗口
[root@localhost home]# docker images
REPOSITORY            TAG       IMAGE ID       CREATED          SIZE
huangjialin/centos    1.0       74f0e59c6da4   18 minutes ago   209MB
tomcat02.1.0          latest    f5946bde7e99   5 hours ago      672MB
tomcat                8         926c7fd4777e   35 hours ago     533MB
tomcat                latest    bd431ca8553c   35 hours ago     667MB
nginx                 latest    519e12e2a84a   2 days ago       133MB
mysql                 5.7       450379344707   2 days ago       449MB
portainer/portainer   latest    580c0e4e98b0   3 weeks ago      79.1MB
hello-world           latest    d1165f221234   5 weeks ago      13.3kB
centos                latest    300e315adb2f   4 months ago     209MB
elasticsearch         7.6.2     f29a1ee41030   12 months ago    791MB
[root@localhost home]# docker ps
CONTAINER ID   IMAGE          COMMAND                  CREATED             STATUS             PORTS                   NAMES
f8bd9a180286   74f0e59c6da4   "/bin/bash"              3 minutes ago       Up 3 minutes                               gifted_mccarthy
330f5a75c399   nginx          "/docker-entrypoint.…"   59 minutes ago      Up 59 minutes      0.0.0.0:49154->80/tcp   nginx02
a35688cedc66   nginx          "/docker-entrypoint.…"   About an hour ago   Up About an hour   0.0.0.0:49153->80/tcp   nginx01
[root@localhost home]# docker inspect f8bd9a180286

测试一下刚才的文件是否同步出去了！

[root@localhost home]# cd /var/lib/docker/volumes/52912f4f30befa6a7039dc04b92de15a32ec5de39d3a9db3521f58212e85543d/_data
[root@localhost _data]# ls
container.txt

这种方式使用的十分多，因为我们通常会构建自己的镜像！
假设构建镜像时候没有挂载卷，要手动镜像挂载 -v 卷名：容器内路径！

数据卷容器

多个MySQL同步数据！

命名的容器挂载数据卷！

# 测试 启动3个容器，通过刚才自己写的镜像启动

[root@localhost _data]# docker images
REPOSITORY            TAG       IMAGE ID       CREATED         SIZE
huangjialin/centos    1.0       74f0e59c6da4   2 hours ago     209MB
tomcat02.1.0          latest    f5946bde7e99   6 hours ago     672MB
tomcat                8         926c7fd4777e   37 hours ago    533MB
tomcat                latest    bd431ca8553c   37 hours ago    667MB
nginx                 latest    519e12e2a84a   2 days ago      133MB
mysql                 5.7       450379344707   2 days ago      449MB
portainer/portainer   latest    580c0e4e98b0   3 weeks ago     79.1MB
hello-world           latest    d1165f221234   5 weeks ago     13.3kB
centos                latest    300e315adb2f   4 months ago    209MB
elasticsearch         7.6.2     f29a1ee41030   12 months ago   791MB



# 创建docker01：因为我本机是最新版，故这里用latest，狂神老师用的是1.0如下图
[root@localhost _data]#  docker run -it --name docker01 huangjialin/centos:1.0

# 查看容器docekr01内容
[root@8e2660858dca /]# ls
bin  dev  etc  home  lib  lib64  lost+found  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var  volume01	volume02



# 不关闭该容器退出
CTRL + Q + P  

# 创建docker02: 并且让docker02 继承 docker01
[root@localhost /]# docker run -it --name docker02 --volumes-from docker01 huangjialin/centos:1.0

# 查看容器docker02内容
[root@465894e34af8 /]# ls
bin  dev  etc  home  lib  lib64  lost+found  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var  volume01	volume02

# 进入docker01
[root@localhost /]# docker ps
CONTAINER ID   IMAGE                    COMMAND                  CREATED         STATUS         PORTS     NAMES
465894e34af8   huangjialin/centos:1.0   "/bin/sh -c /bin/bash"   2 minutes ago   Up 2 minutes             docker02
8e2660858dca   huangjialin/centos:1.0   "/bin/sh -c /bin/bash"   3 minutes ago   Up 3 minutes             docker01
[root@localhost /]# docker attach 8e2660858dca
[root@8e2660858dca /]# ls -l
total 0
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 bin -> usr/bin
drwxr-xr-x.   5 root root 360 Apr 13 05:47 dev
drwxr-xr-x.   1 root root  66 Apr 13 05:47 etc
drwxr-xr-x.   2 root root   6 Nov  3 15:22 home
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 lib -> usr/lib
lrwxrwxrwx.   1 root root   9 Nov  3 15:22 lib64 -> usr/lib64
drwx------.   2 root root   6 Dec  4 17:37 lost+found
drwxr-xr-x.   2 root root   6 Nov  3 15:22 media
drwxr-xr-x.   2 root root   6 Nov  3 15:22 mnt
drwxr-xr-x.   2 root root   6 Nov  3 15:22 opt
dr-xr-xr-x. 242 root root   0 Apr 13 05:47 proc
dr-xr-x---.   2 root root 162 Dec  4 17:37 root
drwxr-xr-x.  11 root root 163 Dec  4 17:37 run
lrwxrwxrwx.   1 root root   8 Nov  3 15:22 sbin -> usr/sbin
drwxr-xr-x.   2 root root   6 Nov  3 15:22 srv
dr-xr-xr-x.  13 root root   0 Apr 13 05:27 sys
drwxrwxrwt.   7 root root 145 Dec  4 17:37 tmp
drwxr-xr-x.  12 root root 144 Dec  4 17:37 usr
drwxr-xr-x.  20 root root 262 Dec  4 17:37 var
drwxr-xr-x.   2 root root   6 Apr 13 05:47 volume01
drwxr-xr-x.   2 root root   6 Apr 13 05:47 volume02
# 创建文件
[root@8e2660858dca /]# cd volume01
[root@8e2660858dca volume01]# ls
[root@8e2660858dca volume01]# touch docker01

# 进入docker02
[root@localhost /]# docker attach 465894e34af8
[root@465894e34af8 /]# ls  -l
total 0
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 bin -> usr/bin
drwxr-xr-x.   5 root root 360 Apr 13 05:48 dev
drwxr-xr-x.   1 root root  66 Apr 13 05:48 etc
drwxr-xr-x.   2 root root   6 Nov  3 15:22 home
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 lib -> usr/lib
lrwxrwxrwx.   1 root root   9 Nov  3 15:22 lib64 -> usr/lib64
drwx------.   2 root root   6 Dec  4 17:37 lost+found
drwxr-xr-x.   2 root root   6 Nov  3 15:22 media
drwxr-xr-x.   2 root root   6 Nov  3 15:22 mnt
drwxr-xr-x.   2 root root   6 Nov  3 15:22 opt
dr-xr-xr-x. 241 root root   0 Apr 13 05:48 proc
dr-xr-x---.   2 root root 162 Dec  4 17:37 root
drwxr-xr-x.  11 root root 163 Dec  4 17:37 run
lrwxrwxrwx.   1 root root   8 Nov  3 15:22 sbin -> usr/sbin
drwxr-xr-x.   2 root root   6 Nov  3 15:22 srv
dr-xr-xr-x.  13 root root   0 Apr 13 05:27 sys
drwxrwxrwt.   7 root root 145 Dec  4 17:37 tmp
drwxr-xr-x.  12 root root 144 Dec  4 17:37 usr
drwxr-xr-x.  20 root root 262 Dec  4 17:37 var
drwxr-xr-x.   2 root root  22 Apr 13 05:55 volume01
drwxr-xr-x.   2 root root   6 Apr 13 05:47 volume02
# 发现docker01创建的文件
[root@465894e34af8 /]# cd volume01
[root@465894e34af8 volume01]# ls
docker01

各个容器之间的数据共享
亲测删除也会同步

# 再新建一个docker03同样继承docker01
$ docker run -it --name docker03 --volumes-from docker01 caoshipeng/centos:latest
$ cd volume01	#进入volume01 查看是否也同步docker01的数据
$ ls 
docker01.txt

# 测试：可以删除docker01，查看一下docker02和docker03是否可以访问这个文件
# 测试发现：数据依旧保留在docker02和docker03中没有被删除

多个mysql实现数据共享

$ docker run -d -p 3306:3306 -v /home/mysql/conf:/etc/mysql/conf.d -v /home/mysql/data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 --name mysql01 mysql:5.7

$ docker run -d -p 3310:3306 -e MYSQL_ROOT_PASSWORD=123456 --name mysql02 --volumes-from mysql01  mysql:5.7

# 这个时候，可以实现两个容器数据同步！

结论

容器之间的配置信息的传递，数据卷容器的生命周期一直持续到没有容器使用为止。

但是一旦你持久化到了本地，这个时候，本地的数据是不会删除的！

DockerFile

DockerFile介绍

dockerfile是用来构建docker镜像的文件！命令参数脚本！

构建步骤：

1、 编写一个dockerfile文件

2、 docker build 构建称为一个镜像

3、 docker run运行镜像

4、 docker push发布镜像（DockerHub 、阿里云仓库)

点击链接跳转到GitHub

很多官方镜像都是基础包，很多功能没有，我们通常会自己搭建自己的镜像！

官方既然可以制作镜像，那我们也可以！

DockerFile构建过程

基础知识：

1、每个保留关键字(指令）都是必须是大写字母

2、执行从上到下顺序

3、#表示注释

4、每一个指令都会创建提交一个新的镜像层，并提交！

Dockerfile是面向开发的，我们以后要发布项目，做镜像，就需要编写dockerfile文件，这个文件十分简单！

Docker镜像逐渐成企业交付的标准，必须要掌握！

步骤：开发、部署、运维缺一不可

DockerFile：构建文件，定义了一切的步骤，源代码

DockerImages：通过DockerFile构建生成的镜像，最终发布和运行产品。

Docker容器：容器就是镜像运行起来提供服务。

DockerFile的指令

FROM				# from:基础镜像，一切从这里开始构建
MAINTAINER			# maintainer:镜像是谁写的， 姓名+邮箱
RUN					# run:镜像构建的时候需要运行的命令
ADD					# add:步骤，tomcat镜像，这个tomcat压缩包！添加内容 添加同目录
WORKDIR				# workdir:镜像的工作目录
VOLUME				# volume:挂载的目录
EXPOSE				# expose:保留端口配置
CMD					# cmd:指定这个容器启动的时候要运行的命令，只有最后一个会生效，可被替代
ENTRYPOINT			# entrypoint:指定这个容器启动的时候要运行的命令，可以追加命令
ONBUILD				# onbuild:当构建一个被继承DockerFile这个时候就会运行onbuild的指令，触发指令
COPY				# copy:类似ADD，将我们文件拷贝到镜像中
ENV					# env:构建的时候设置环境变量！

实战测试

scratch 镜像

FROM scratch
ADD centos-7-x86_64-docker.tar.xz /

LABEL \
    org.label-schema.schema-version="1.0" \
    org.label-schema.name="CentOS Base Image" \
    org.label-schema.vendor="CentOS" \
    org.label-schema.license="GPLv2" \
    org.label-schema.build-date="20200504" \
    org.opencontainers.image.title="CentOS Base Image" \
    org.opencontainers.image.vendor="CentOS" \
    org.opencontainers.image.licenses="GPL-2.0-only" \
    org.opencontainers.image.created="2020-05-04 00:00:00+01:00"

CMD ["/bin/bash"]

Docker Hub 中 99%的镜像都是从这个基础镜像过来的 FROM scratch，然后配置需要的软件和配置来进行构建。

创建一个自己的centos

# 1./home下新建dockerfile目录
[root@localhost /]# cd home
[root@localhost home]# mkdir dockerfile

# 2. dockerfile目录下新建mydockerfile-centos文件
[root@localhost home]# cd dockerfile/

[root@localhost dockerfile]# vim mydockerfile-centos

# 3.编写Dockerfile配置文件
FROM centos							# 基础镜像是官方原生的centos
MAINTAINER huangjialin<2622046365@qq.com>	# 作者

ENV MYPATH /usr/local				# 配置环境变量的目录 
WORKDIR $MYPATH						# 将工作目录设置为 MYPATH

RUN yum -y install vim				# 给官方原生的centos 增加 vim指令
RUN yum -y install net-tools		# 给官方原生的centos 增加 ifconfig命令

EXPOSE 80							# 暴露端口号为80

CMD echo $MYPATH					# 输出下 MYPATH 路径
CMD echo "-----end----"				
CMD /bin/bash						# 启动后进入 /bin/bash

# 4.通过这个文件构建镜像
# 命令： docker build -f 文件路径 -t 镜像名:[tag] .
[root@localhost dockerfile]# docker build -f mydockerfile-centos -t mysentos:0.1 .

# 5.出现下图后则构建成功
Successfully built 2315251fefdd
Successfully tagged mysentos:0.1

[root@localhost home]# docker images
REPOSITORY            TAG       IMAGE ID       CREATED          SIZE
mysentos              0.1       2315251fefdd   52 seconds ago   291MB
huangjialin/centos    1.0       74f0e59c6da4   18 hours ago     209MB
tomcat02.1.0          latest    f5946bde7e99   22 hours ago     672MB
tomcat                8         926c7fd4777e   2 days ago       533MB
tomcat                latest    bd431ca8553c   2 days ago       667MB
nginx                 latest    519e12e2a84a   3 days ago       133MB
mysql                 5.7       450379344707   3 days ago       449MB
portainer/portainer   latest    580c0e4e98b0   3 weeks ago      79.1MB
hello-world           latest    d1165f221234   5 weeks ago      13.3kB
centos                latest    300e315adb2f   4 months ago     209MB
elasticsearch         7.6.2     f29a1ee41030   12 months ago    791MB

# 6.测试运行
[root@localhost home]# docker run -it mysentos:0.1		# 注意带上版本号，否则每次都回去找最新版latest

[root@468db5f02628 local]# pwd	
/usr/local							# 与Dockerfile文件中 WORKDIR 设置的 MYPATH 一致
[root@468db5f02628 local]# vim								# vim 指令可以使用
[root@468db5f02628 local]# ifconfig     						# ifconfig 指令可以使用

# docker history 镜像id 查看镜像构建历史步骤
[root@localhost home]# docker history 2315251fefdd
IMAGE          CREATED         CREATED BY                                      SIZE      COMMENT
2315251fefdd   6 minutes ago   /bin/sh -c #(nop)  CMD ["/bin/sh" "-c" "/bin…   0B        
be99d496b25c   6 minutes ago   /bin/sh -c #(nop)  CMD ["/bin/sh" "-c" "echo…   0B        
34fd97cceb13   6 minutes ago   /bin/sh -c #(nop)  CMD ["/bin/sh" "-c" "echo…   0B        
baa95b2530ae   6 minutes ago   /bin/sh -c #(nop)  EXPOSE 80                    0B        
ef9b50de0b5b   6 minutes ago   /bin/sh -c yum -y install net-tools             23.4MB    
071ef8153ad4   6 minutes ago   /bin/sh -c yum -y install vim                   58.1MB    
d6a38a2948f3   7 minutes ago   /bin/sh -c #(nop) WORKDIR /usr/local            0B        
98bd16198bff   7 minutes ago   /bin/sh -c #(nop)  ENV MYPATH=/usr/local        0B        
53816b10cd26   7 minutes ago   /bin/sh -c #(nop)  MAINTAINER huangjialin<26…   0B        
300e315adb2f   4 months ago    /bin/sh -c #(nop)  CMD ["/bin/bash"]            0B        
      4 months ago    /bin/sh -c #(nop)  LABEL org.label-schema.sc…   0B        
      4 months ago    /bin/sh -c #(nop) ADD file:bd7a2aed6ede423b7…   209MB     

之前的

之后的

变更历史

我们平时拿到一个镜像，可以用 “docker history 镜像id” 研究一下是什么做的

CMD 和 ENTRYPOINT区别

CMD					# 指定这个容器启动的时候要运行的命令，只有最后一个会生效，可被替代。
ENTRYPOINT			# 指定这个容器启动的时候要运行的命令，可以追加命令

测试CMD

# 编写dockerfile文件
[root@localhost dockerfile]# vim dockerfile-test-cmd
FROM centos
CMD ["ls","-a"]					# 启动后执行 ls -a 命令

# CMD [] :要运行的命令是存放在一个数组结构中的。

# 构建镜像
[root@localhost dockerfile]# docker build -f dockerfile-test-cmd -t cmd-test:0.1 .
Sending build context to Docker daemon  3.072kB
Step 1/2 : FROM centos
 ---> 300e315adb2f
Step 2/2 : CMD ["ls","-a"]
 ---> Running in 3d990f51fd5a
Removing intermediate container 3d990f51fd5a
 ---> 0e927777d383
Successfully built 0e927777d383
Successfully tagged cmd-test:0.1

# 运行镜像
[root@localhost dockerfile]# docker run 0e927777d383		# 由结果可得，运行后就执行了 ls -a 命令
.
..
.dockerenv
bin
dev
etc
home
lib
lib64
lost+found
media
mnt
opt
proc
root
run
sbin
srv
sys
tmp
usr
var


# 想追加一个命令  -l 成为ls -al：展示列表详细数据
[root@localhost dockerfile]# docker run cmd-test:0.1 -l
docker: Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "exec: \"-l\":
executable file not found in $PATH": unknown.
ERRO[0000] error waiting for container: context canceled 

# cmd的情况下 -l 替换了CMD["ls","-l"] 而 -l  不是命令所以报错

[root@localhost dockerfile]# docker run 0e927777d383 ls -al
total 0
drwxr-xr-x.   1 root root   6 Apr 13 08:38 .
drwxr-xr-x.   1 root root   6 Apr 13 08:38 ..
-rwxr-xr-x.   1 root root   0 Apr 13 08:38 .dockerenv
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 bin -> usr/bin
drwxr-xr-x.   5 root root 340 Apr 13 08:38 dev
drwxr-xr-x.   1 root root  66 Apr 13 08:38 etc
drwxr-xr-x.   2 root root   6 Nov  3 15:22 home
lrwxrwxrwx.   1 root root   7 Nov  3 15:22 lib -> usr/lib
lrwxrwxrwx.   1 root root   9 Nov  3 15:22 lib64 -> usr/lib64
drwx------.   2 root root   6 Dec  4 17:37 lost+found
drwxr-xr-x.   2 root root   6 Nov  3 15:22 media
drwxr-xr-x.   2 root root   6 Nov  3 15:22 mnt
drwxr-xr-x.   2 root root   6 Nov  3 15:22 opt
dr-xr-xr-x. 247 root root   0 Apr 13 08:38 proc
dr-xr-x---.   2 root root 162 Dec  4 17:37 root
drwxr-xr-x.  11 root root 163 Dec  4 17:37 run
lrwxrwxrwx.   1 root root   8 Nov  3 15:22 sbin -> usr/sbin
drwxr-xr-x.   2 root root   6 Nov  3 15:22 srv
dr-xr-xr-x.  13 root root   0 Apr 13 05:27 sys
drwxrwxrwt.   7 root root 145 Dec  4 17:37 tmp
drwxr-xr-x.  12 root root 144 Dec  4 17:37 usr
drwxr-xr-x.  20 root root 262 Dec  4 17:37 var

测试ENTRYPOINT

# 编写dockerfile文件
$ vim dockerfile-test-entrypoint
FROM centos
ENTRYPOINT ["ls","-a"]

# 构建镜像
$ docker build  -f dockerfile-test-entrypoint -t cmd-test:0.1 .

# 运行镜像
$ docker run entrypoint-test:0.1
.
..
.dockerenv
bin
dev
etc
home
lib
lib64
lost+found ...

# 我们的命令，是直接拼接在我们得ENTRYPOINT命令后面的
$ docker run entrypoint-test:0.1 -l
total 56
drwxr-xr-x   1 root root 4096 May 16 06:32 .
drwxr-xr-x   1 root root 4096 May 16 06:32 ..
-rwxr-xr-x   1 root root    0 May 16 06:32 .dockerenv
lrwxrwxrwx   1 root root    7 May 11  2019 bin -> usr/bin
drwxr-xr-x   5 root root  340 May 16 06:32 dev
drwxr-xr-x   1 root root 4096 May 16 06:32 etc
drwxr-xr-x   2 root root 4096 May 11  2019 home
lrwxrwxrwx   1 root root    7 May 11  2019 lib -> usr/lib
lrwxrwxrwx   1 root root    9 May 11  2019 lib64 -> usr/lib64 ....

Dockerfile中很多命令都十分的相似，我们需要了解它们的区别，我们最好的学习就是对比他们然后测试效果！

实战：Tomcat镜像

1、准备镜像文件

准备tomcat 和 jdk 到当前目录，编写好README

[root@localhost /]# cd /home
[root@localhost home]# ls
ceshi  dockerfile  docker-test-volume  huang.java  huangjialin  huang.txt  mylinux  mysql  test.java  testTmp
[root@localhost home]# cd huangjialin
[root@localhost huangjialin]# ls
datas  Desktop  Documents  Downloads  Music  Pictures  Public  Templates  Videos
# 创建目录
[root@localhost huangjialin]# mkdir -vp build/tomcat
mkdir: created directory ‘build’
mkdir: created directory ‘build/tomcat’
[root@localhost huangjialin]# ls
build  datas  Desktop  Documents  Downloads  Music  Pictures  Public  Templates  Videos
[root@localhost huangjialin]# cd build
[root@localhost build]# cd tomcat
# 根据下图导入数据包
[root@localhost tomcat]# ls
apache-tomcat-9.0.45.tar.gz  jdk-8u221-linux-x64.tar.gz

2、编写dokerfile

官方命名Dockerfile,build会自动寻找这个文件,就不需要-f指定了!

[root@localhost tomcat]# ls
apache-tomcat-9.0.45.tar.gz  jdk-8u221-linux-x64.tar.gz
[root@localhost tomcat]# touch readme.txt
[root@localhost tomcat]# vim Dockerfile

FROM centos 										# 基础镜像centos
MAINTAINER huangjialin<2622046365@qq.com>					# 作者
COPY readme.txt /usr/local/readme.txt						# 复制README文件
ADD jdk-8u221-linux-x64.tar.gz /usr/local/ 			# 添加jdk，ADD 命令会自动解压
ADD apache-tomcat-9.0.45.tar.gz /usr/local/ 		# 添加tomcat，ADD 命令会自动解压
RUN yum -y install vim								# 安装 vim 命令
ENV MYPATH /usr/local 								# 环境变量设置 工作目录
WORKDIR $MYPATH

ENV JAVA_HOME /usr/local/jdk1.8.0_221 				# 环境变量： JAVA_HOME环境变量
ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

ENV CATALINA_HOME /usr/local/apache-tomcat-9.0.45 	# 环境变量： tomcat环境变量
ENV CATALINA_BASH /usr/local/apache-tomcat-9.0.45

# 设置环境变量 分隔符是：
ENV PATH $PATH:$JAVA_HOME/bin:$CATALINA_HOME/lib:$CATALINA_HOME/bin 	

EXPOSE 8080 										# 设置暴露的端口

CMD /usr/local/apache-tomcat-9.0.45/bin/startup.sh && tail -F /usr/local/apache-tomcat-9.0.45/logs/catalina.out 					# 设置默认命令

3、构建镜像

# 因为Dockerfile命名使用默认命名 因此不用使用-f 指定文件
[root@localhost tomcat]# docker build -t diytomcat .

运行成功

[root@localhost tomcat]# docker build -t diytomcat .
Sending build context to Docker daemon  206.6MB
Step 1/15 : FROM centos
 ---> 300e315adb2f
Step 2/15 : MAINTAINER huangjialin<2622046365@qq.com>
 ---> Using cache
 ---> 53816b10cd26
Step 3/15 : COPY readme.txt /usr/local/readme.txt
 ---> b17277a321e4
Step 4/15 : ADD jdk-8u221-linux-x64.tar.gz /usr/local/
 ---> bf206090dd5b
Step 5/15 : ADD apache-tomcat-9.0.45.tar.gz /usr/local/
 ---> e7e5d7cb0c43
Step 6/15 : RUN yum -y install vim
 ---> Running in 7984f5e786a8
CentOS Linux 8 - AppStream                      791 kB/s | 6.3 MB     00:08    
CentOS Linux 8 - BaseOS                         1.2 MB/s | 2.3 MB     00:01    
CentOS Linux 8 - Extras                          18 kB/s | 9.6 kB     00:00    
Last metadata expiration check: 0:00:01 ago on Tue Apr 13 11:41:15 2021.
Dependencies resolved.
================================================================================
 Package             Arch        Version                   Repository      Size
================================================================================
Installing:
 vim-enhanced        x86_64      2:8.0.1763-15.el8         appstream      1.4 M
Installing dependencies:
 gpm-libs            x86_64      1.20.7-15.el8             appstream       39 k
 vim-common          x86_64      2:8.0.1763-15.el8         appstream      6.3 M
 vim-filesystem      noarch      2:8.0.1763-15.el8         appstream       48 k
 which               x86_64      2.21-12.el8               baseos          49 k

Transaction Summary
================================================================================
Install  5 Packages

Total download size: 7.8 M
Installed size: 30 M
Downloading Packages:
(1/5): gpm-libs-1.20.7-15.el8.x86_64.rpm        187 kB/s |  39 kB     00:00    
(2/5): vim-filesystem-8.0.1763-15.el8.noarch.rp 402 kB/s |  48 kB     00:00    
(3/5): which-2.21-12.el8.x86_64.rpm             106 kB/s |  49 kB     00:00    
(4/5): vim-enhanced-8.0.1763-15.el8.x86_64.rpm  500 kB/s | 1.4 MB     00:02    
(5/5): vim-common-8.0.1763-15.el8.x86_64.rpm    599 kB/s | 6.3 MB     00:10    
--------------------------------------------------------------------------------
Total                                           672 kB/s | 7.8 MB     00:11     
warning: /var/cache/dnf/appstream-02e86d1c976ab532/packages/gpm-libs-1.20.7-15.el8.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID 8483c65d: NOKEY
CentOS Linux 8 - AppStream                      107 kB/s | 1.6 kB     00:00    
Importing GPG key 0x8483C65D:
 Userid     : "CentOS (CentOS Official Signing Key) "
 Fingerprint: 99DB 70FA E1D7 CE22 7FB6 4882 05B5 55B3 8483 C65D
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
Key imported successfully
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : which-2.21-12.el8.x86_64                               1/5 
  Installing       : vim-filesystem-2:8.0.1763-15.el8.noarch                2/5 
  Installing       : vim-common-2:8.0.1763-15.el8.x86_64                    3/5 
  Installing       : gpm-libs-1.20.7-15.el8.x86_64                          4/5 
  Running scriptlet: gpm-libs-1.20.7-15.el8.x86_64                          4/5 
  Installing       : vim-enhanced-2:8.0.1763-15.el8.x86_64                  5/5 
  Running scriptlet: vim-enhanced-2:8.0.1763-15.el8.x86_64                  5/5 
  Running scriptlet: vim-common-2:8.0.1763-15.el8.x86_64                    5/5 
  Verifying        : gpm-libs-1.20.7-15.el8.x86_64                          1/5 
  Verifying        : vim-common-2:8.0.1763-15.el8.x86_64                    2/5 
  Verifying        : vim-enhanced-2:8.0.1763-15.el8.x86_64                  3/5 
  Verifying        : vim-filesystem-2:8.0.1763-15.el8.noarch                4/5 
  Verifying        : which-2.21-12.el8.x86_64                               5/5 

Installed:
  gpm-libs-1.20.7-15.el8.x86_64         vim-common-2:8.0.1763-15.el8.x86_64    
  vim-enhanced-2:8.0.1763-15.el8.x86_64 vim-filesystem-2:8.0.1763-15.el8.noarch
  which-2.21-12.el8.x86_64             

Complete!
Removing intermediate container 7984f5e786a8
 ---> 5e55934a1698
Step 7/15 : ENV MYPATH /usr/local
 ---> Running in 1c27b1556650
Removing intermediate container 1c27b1556650
 ---> bf7676c461b7
Step 8/15 : WORKDIR $MYPATH
 ---> Running in ea7b376828ee
Removing intermediate container ea7b376828ee
 ---> 829e13be0dd2
Step 9/15 : ENV JAVA_HOME /usr/local/jdk1.8.0_221
 ---> Running in e870347689db
Removing intermediate container e870347689db
 ---> 9addfa9f2af9
Step 10/15 : ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
 ---> Running in 35be0d0d1e87
Removing intermediate container 35be0d0d1e87
 ---> 2b8399db457f
Step 11/15 : ENV CATALINA_HOME /usr/local/apache-tomcat-9.0.45
 ---> Running in 6268510dbb10
Removing intermediate container 6268510dbb10
 ---> f587d0e0d7b1
Step 12/15 : ENV CATALINA_BASH /usr/local/apache-tomcat-9.0.45
 ---> Running in 584842f44cb2
Removing intermediate container 584842f44cb2
 ---> 9352b4a38800
Step 13/15 : ENV PATH $PATH:$JAVA_HOME/bin:$CATALINA_HOME/lib:$CATALINA_HOME/bin
 ---> Running in 3882c79944b1
Removing intermediate container 3882c79944b1
 ---> 2189e809aa16
Step 14/15 : EXPOSE 8080
 ---> Running in 2fdcc0bb062d
Removing intermediate container 2fdcc0bb062d
 ---> 2ada2912e565
Step 15/15 : CMD /usr/local/apache-tomcat-9.0.45/bin/startup.sh && tail -F /usr/local/apache-tomcat-9.0.45/logs/catalina.out
 ---> Running in b5253d274a87
Removing intermediate container b5253d274a87
 ---> 62c96b0fe815
Successfully built 62c96b0fe815
Successfully tagged diytomcat:latest

4、run镜像

# -d:后台运行 -p:暴露端口 --name:别名 -v:绑定路径 
[root@localhost tomcat]# docker run -d -p 9090:8080 --name diytomcat -v /home/huangjialin/build/tomcat/test:/usr/local/apache-tomcat-9.0.45/webapps/test -v /home/huangjialin/build/tomcat/tomcatlogs/:/usr/local/apache-tomcat-9.0.45/logs diytomcat
eefdce2320da80a26d04951fa62ead9155260c9ec2fc7195fb5d78332e70b20e
[root@localhost tomcat]# docker exec -it eefdce2320da80a2 /bin/bash
[root@eefdce2320da local]# ls
apache-tomcat-9.0.45  bin  etc	games  include	jdk1.8.0_221  lib  lib64  libexec  readme.txt  sbin  share  src
[root@eefdce2320da local]# pwd
/usr/local
[root@eefdce2320da local]# ls -l
total 0
drwxr-xr-x. 1 root root  45 Apr 13 11:40 apache-tomcat-9.0.45
drwxr-xr-x. 2 root root   6 Nov  3 15:22 bin
drwxr-xr-x. 2 root root   6 Nov  3 15:22 etc
drwxr-xr-x. 2 root root   6 Nov  3 15:22 games
drwxr-xr-x. 2 root root   6 Nov  3 15:22 include
drwxr-xr-x. 7   10  143 245 Jul  4  2019 jdk1.8.0_221
drwxr-xr-x. 2 root root   6 Nov  3 15:22 lib
drwxr-xr-x. 3 root root  17 Dec  4 17:37 lib64
drwxr-xr-x. 2 root root   6 Nov  3 15:22 libexec
-rw-r--r--. 1 root root   0 Apr 13 11:24 readme.txt
drwxr-xr-x. 2 root root   6 Nov  3 15:22 sbin
drwxr-xr-x. 5 root root  49 Dec  4 17:37 share
drwxr-xr-x. 2 root root   6 Nov  3 15:22 src
[root@eefdce2320da local]# cd apache-tomcat-9.0.45/
[root@eefdce2320da apache-tomcat-9.0.45]# ls
BUILDING.txt  CONTRIBUTING.md  LICENSE	NOTICE	README.md  RELEASE-NOTES  RUNNING.txt  bin  conf  lib  logs  temp  webapps  work
[root@eefdce2320da apache-tomcat-9.0.45]# ls -l
total 128
-rw-r-----. 1 root root 18984 Mar 30 10:29 BUILDING.txt
-rw-r-----. 1 root root  5587 Mar 30 10:29 CONTRIBUTING.md
-rw-r-----. 1 root root 57092 Mar 30 10:29 LICENSE
-rw-r-----. 1 root root  2333 Mar 30 10:29 NOTICE
-rw-r-----. 1 root root  3257 Mar 30 10:29 README.md
-rw-r-----. 1 root root  6898 Mar 30 10:29 RELEASE-NOTES
-rw-r-----. 1 root root 16507 Mar 30 10:29 RUNNING.txt
drwxr-x---. 2 root root  4096 Mar 30 10:29 bin
drwx------. 1 root root    22 Apr 13 12:34 conf
drwxr-x---. 2 root root  4096 Mar 30 10:29 lib
drwxr-xr-x. 2 root root   197 Apr 13 12:34 logs
drwxr-x---. 2 root root    30 Mar 30 10:29 temp
drwxr-x---. 1 root root    18 Apr 13 12:34 webapps
drwxr-x---. 1 root root    22 Apr 13 12:34 work

# 另一个窗口
[root@localhost tomcat]# curl localhost:9090
<!DOCTYPE html>
"en">
    
        "UTF-8" />