一、Docker镜像的创建方法

1.基于已有镜像创建

命令格式： docker commit 【选项】 容器ID/名称 仓库名称：标签
常用选项：
-m ：说明信息
-a ：作者信息
-p ：生成过程中停止容器的运行

例如

[root@localhost tomcat]# docker images //查看当前镜像
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
tomcat       v6        f7a49d73a02d   22 minutes ago   964MB
[root@localhost tomcat]# docker ps   //查看当前运行容器
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                                         NAMES
f03d993ef837   tomcat:v6   "/bin/sh -c '/usr/lo…"   22 minutes ago   Up 22 minutes   0.0.0.0:49169->8080/tcp, :::49169->8080/tcp   nifty_lovelace
[root@localhost tomcat]# docker commit f03d993ef837 tomcat:v7  //基于已有容器创建新的镜像
sha256:f76c0cb8b7e00935964ea125be00b01f705ca78170116c62bb3cd48d1d8b0547
[root@localhost tomcat]# docker images    //14s前创建的镜像
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
tomcat       v7        f76c0cb8b7e0   14 seconds ago   964MB
tomcat       v6        f7a49d73a02d   24 minutes ago   964MB
[root@localhost tomcat]#

2.基于本地模板创建

[root@localhost tomcat]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                                         NAMES
f03d993ef837   tomcat:v6   "/bin/sh -c '/usr/lo…"   39 minutes ago   Up 39 minutes   0.0.0.0:49169->8080/tcp, :::49169->8080/tcp   nifty_lovelace
[root@localhost tomcat]# docker export nifty_lovelace > tomcat.tar.gz
[root@localhost tomcat]# cat tomcat.tar.gz | docker import - tomcat:v8
sha256:e06d12bf2b7a6757b94660853c9b939b174fea700c428c473fd26e373eeb963e
[root@localhost tomcat]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED              SIZE
tomcat       v8        e06d12bf2b7a   About a minute ago   584MB
tomcat       v7        f76c0cb8b7e0   About an hour ago    964MB
tomcat       v6        f7a49d73a02d   About an hour ago    964MB

3.基于Dockerfile创建

Dokcerfile操作指令

指令	含义
FROM 镜像	指定新镜像所基于的镜像，第一条指令必须为FROM指令
MAINTAINER 名字	说明新镜像的维护人信息
RUN 命令	在所基于的镜像上执行命令，并提交到新的镜像中
CMD 【“要运行的程序”，“参数1”，“参数2”】	指定启动容器时要运行的命令或者脚本，Dockerfile只能有一条CMD命令，如果指定多条则只有一条被执行
EXPOSE 端口号	指定新镜像加载到Docker时要开启的端口
ENV 环境变量变量值	设置一个环境变量的值，会被后面的RUN使用
ADD 源文件/目录目标文件/目录	将源文件复制到目标文件，源文件要与Dockerfile位于相同目录中，或者是一个URL
COPY 源文件/目录目标文件/目录	将本地主机上的源文件/目录复制到目标地点，源文件/目录要与Dockerfile在相同的目录中
VOLUME 【“目录”】	在容器中创建一个挂载点
USER 用户名 /UID	指定运行容器时的用户
WORKDIR 路径	为后续的RUN、CMD、ENTRYPOINT指定工作目录
ONBUILD命令	指定所生成的镜像作为一个基础镜像时所要运行的命令

例如：

[root@localhost ~]# mkdir tomcat  //创建工作目录
[root@localhost ~]# cd tomcat/    //切换目录
[root@localhost tomcat]# ls       //上传jdk。tomcat进入此目录
apache-tomcat-9.0.16.tar.gz   jdk-8u91-linux-x64.tar.gz
[root@localhost tomcat]# vim Dockerfile //编写Dokcerfile文件

FROM centos:7   //基于基础镜像
MAINTAINER this is tomcat image   //用户信息
ADD jdk-8u91-linux-x64.tar.gz /usr/local/  //复制到指定目录并解压
WORKDIR /usr/local/     //指定工作目录
RUN mv jdk1.8.0_91 /usr/local/java   //改名
ENV JAVA_HOME /usr/local/java    //添加环境变量
ENV JRE_HOME ${JAVA_HOME}/jre
ENV CLASSPATH .:${JAVA_HOME}/lib:${JRE_HOME}/lib
ENV PATH $JAVA_HOME/bin:$PATH
ADD apache-tomcat-9.0.16.tar.gz /usr/local/  //复制文件到指定目录并解压
RUN mv apache-tomcat-9.0.16 /usr/local/tomcat  //解压
WORKDIR /usr/local/tomcat/bin   //指定工作目录
EXPOSE 8080   //暴露端口
ENTRYPOINT /usr/local/tomcat/bin/startup.sh && tail -f /usr/local/tomcat/logs/catalina.out   //运行tomcat并查看日志（因为执行完主进程后，容器就会退出，所以运行一个主进程使其可以以守护进程的形式在后台运行）

[root@localhost tomcat]# docker build -t tomcat:v1 .  //创建镜像
Sending build context to Docker daemon  192.2MB
Step 1/14 : FROM centos:7
7: Pulling from library/centos
2d473b07cdd5: Pull complete 
Digest: sha256:0f4ec88e21daf75124b8a9e5ca03c37a5e937e0e108a255d890492430789b60e
Status: Downloaded newer image for centos:7
 ---> 8652b9f0cb4c
Step 2/14 : MAINTAINER this is tomcat image
 ---> Running in a5532074ed3b
Removing intermediate container a5532074ed3b
 ---> 71779be7bb6b
Step 3/14 : ADD jdk-8u91-linux-x64.tar.gz /usr/local/
 ---> 825dc697ac91
Step 4/14 : WORKDIR /usr/local/
 ---> Running in 55fa7448be7d
Removing intermediate container 55fa7448be7d
 ---> e5204e622950
Step 5/14 : RUN mv jdk1.8.0_91 /usr/local/java
 ---> Running in f75255a5f6de
Removing intermediate container f75255a5f6de
 ---> 688f36307cf6
Step 6/14 : ENV JAVA_HOME /usr/local/java
 ---> Running in 8e7836ed0469
Removing intermediate container 8e7836ed0469
 ---> d781f8b9970b
Step 7/14 : ENV JRE_HOME ${JAVA_HOME}/jre
 ---> Running in c287ef31da84
Removing intermediate container c287ef31da84
 ---> 2b91344cceea
Step 8/14 : ENV CLASSPATH .:${JAVA_HOME}/lib:${JRE_HOME}/lib
 ---> Running in 18a913acaaed
Removing intermediate container 18a913acaaed
 ---> 8d963d1baade
Step 9/14 : ENV PATH $JAVA_HOME/bin:$PATH
 ---> Running in a0835d791cbc
Removing intermediate container a0835d791cbc
 ---> 15bce63ddd4e
Step 10/14 : ADD apache-tomcat-9.0.16.tar.gz /usr/local/
 ---> 1ddb362b6286
Step 11/14 : RUN mv apache-tomcat-9.0.16 /usr/local/tomcat
 ---> Running in 4b2992f274c2
Removing intermediate container 4b2992f274c2
 ---> a6ba9f1468f7
Step 12/14 : WORKDIR /usr/local/tomcat/bin
 ---> Running in 238a58b3b96f
Removing intermediate container 238a58b3b96f
 ---> ddda3a7e220f
Step 13/14 : EXPOSE 8080
 ---> Running in b158cff2fa10
Removing intermediate container b158cff2fa10
 ---> 332ed893be0b
Step 14/14 : ENTRYPOINT /usr/local/tomcat/bin/startup.sh && tail -f /usr/local/tomcat/logs/catalina.out
 ---> Running in 6cc3df381c8f
Removing intermediate container 6cc3df381c8f
 ---> e5abb5176221
Successfully built e5abb5176221
Successfully tagged tomcat:v1
[root@localhost tomcat]#

[root@localhost tomcat]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
tomcat       v1        e5abb5176221   57 seconds ago   964MB
centos       7         8652b9f0cb4c   9 months ago     204MB

[root@localhost tomcat]# docker run -d -P --name tomcat tomcat:v1   //基于镜像创建容器
14264289e424e41923ad95e1844076c126d3f57eca4d02eb7bee72a40b2ad9cf
[root@localhost tomcat]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED         STATUS         PORTS                                         NAMES
14264289e424   tomcat:v1   "/bin/sh -c '/usr/lo…"   5 seconds ago   Up 4 seconds   0.0.0.0:49170->8080/tcp, :::49170->8080/tcp   tomcat
[root@localhost tomcat]#

在这里插入图片描述
优化

减少RUN

[root@localhost tomcat]# vim Dockerfile 

FROM centos:7
ADD jdk-8u91-linux-x64.tar.gz /usr/local/
ENV JAVA_HOME /usr/local/jdk1.8.0_91
ENV JRE_HOME ${JAVA_HOME}/jre
ENV CLASSPATH .:${JAVA_HOME}/lib:${JRE_HOME}/lib
ENV PATH $JAVA_HOME/bin:$PATH
ADD apache-tomcat-9.0.16.tar.gz /usr/local/
EXPOSE 8080
ENTRYPOINT /usr/local/apache-tomcat-9.0.16/bin/startup.sh && tail -f /usr/local/apache-tomcat-9.0.16/logs/catalina.out

[root@localhost tomcat]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED          SIZE
tomcat       v2        92d523236981   5 minutes ago    584MB
tomcat       v1        e5abb5176221   41 minutes ago   964MB
centos       7         8652b9f0cb4c   9 months ago     204MB

[root@localhost tomcat]# docker ps -a
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                                         NAMES
e8961371a414   tomcat:v2   "/bin/sh -c '/usr/lo…"   5 minutes ago    Up 5 minutes    0.0.0.0:49174->8080/tcp, :::49174->8080/tcp   tomcatv2
14264289e424   tomcat:v1   "/bin/sh -c '/usr/lo…"   39 minutes ago   Up 39 minutes   0.0.0.0:49170->8080/tcp, :::49170->8080/tcp   tomcat

在这里插入图片描述

二、Docker的数据管理

1.数据卷

1.1 创建数据卷

[root@localhost tomcat]# docker run -d  -v /data1 --name tomcat3 tomcat:v2   //创建一个数据卷挂载到容器内
86fe575915d67e8018bdabba986a55a46be18b14c431bb1270e1281b130334f5
[root@localhost tomcat]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED             STATUS             PORTS                                         NAMES
86fe575915d6   tomcat:v2   "/bin/sh -c '/usr/lo…"   6 seconds ago       Up 6 seconds       8080/tcp                                      tomcat3
e8961371a414   tomcat:v2   "/bin/sh -c '/usr/lo…"   30 minutes ago      Up 30 minutes      0.0.0.0:49174->8080/tcp, :::49174->8080/tcp   tomcatv2
14264289e424   tomcat:v1   "/bin/sh -c '/usr/lo…"   About an hour ago   Up About an hour   0.0.0.0:49170->8080/tcp, :::49170->8080/tcp   tomcat
[root@localhost tomcat]# docker exec -it tomcat3 /bin/bash
[root@86fe575915d6 /]# ls
anaconda-post.log  bin  data1  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var

1.2 挂载主机目录作为数据卷

[root@localhost tomcat]# docker run -d -v /data1:/data1 --name tomcat4 tomcat:v2  //实现宿主机与容器之间的数据迁移
08487b0d03be9fecedc0162e488991e9a8699bfc33f9ce4b272341e93ce7b5b6
[root@localhost tomcat]# docker exec -it tomcat4 /bin/bash
[root@08487b0d03be /]# cd data1/
[root@08487b0d03be data1]# touch 1
[root@08487b0d03be data1]# exit
exit
[root@localhost tomcat]# ls /data1
1
[root@localhost tomcat]#

2.数据卷容器

[root@localhost tomcat]# docker run -d --volumes-from tomcat4 --name tomcat5 tomcat:v2   //挂载tomcat4中的数据卷到tomcat5
2a54095ea3eb5cc640019917ea0203d29c2e963efe9831fa3ed364cd1ceb3cac
[root@localhost tomcat]# docker exec -it tomcat5 /bin/bash
[root@2a54095ea3eb /]# cd data1/
[root@2a54095ea3eb data1]# ls
1
[root@2a54095ea3eb data1]# touch 123
[root@2a54095ea3eb data1]# exit
exit
[root@localhost tomcat]# docker exec -it tomcat4 /bin/bash
[root@08487b0d03be /]# ls data1/
1  123
[root@08487b0d03be /]# exit
exit
[root@localhost tomcat]# ls /data1
1  123
[root@localhost tomcat]#

三、Docker网络通信

1.Docker网络模式

Bridge
使用docker0作为网桥容器，桥接容器与宿主机网络
Host
与宿主机共享网络名称空间/网络协议栈
Container
多个容器之间共享一个网络名称空间/网络协议栈
None
自闭空间

2.Docker自定义网络

1.查看网络列表

[root@localhost tomcat]# docker network ls
NETWORK ID     NAME      DRIVER    SCOPE
27f9d1130e6c   bridge    bridge    local
cfdd984859ec   host      host      local
81ae3de486e7   none      null      local

2.自定义网络固定IP

[root@localhost tomcat]# docker network create --subnet=172.18.0.0/16 mynetwork  //创建新的网段
f317eceed4f9005794371808ee796de15d73cb64e26ebf00f0d2f35434fff9af
[root@localhost tomcat]# docker run -d --name tomcat --net mynetwork --ip 172.18.0.100 tomcat:v2   //固定IP
ea0b00e62fdde8cb3ffdaf94701611e0db844645651a13d0b4d744641025b6d6
[root@localhost tomcat]# docker inspect tomcat | grep "IPA"  //查看IP
            "SecondaryIPAddresses": null,
            "IPAddress": "",
                    "IPAMConfig": {
                    "IPAddress": "172.18.0.100",
[root@localhost tomcat]#

3.端口映射

[root@localhost tomcat]# docker run -d -P tomcat:v2  //映射随机端口
71734dea1499308121abe4d975eb63145927604d5be37a4c140fcbf245f7f6fc
[root@localhost tomcat]# docker run -d -p 8080:8080 tomcat:v2   //映射指定端口
2a59bb35898ca65480463ef1bd24670a1907683ca3905681dc52862bea1fed05
[root@localhost tomcat]# docker ps
CONTAINER ID   IMAGE       COMMAND                  CREATED          STATUS          PORTS                                         NAMES
2a59bb35898c   tomcat:v2   "/bin/sh -c '/usr/lo…"   5 seconds ago    Up 4 seconds    0.0.0.0:8080->8080/tcp, :::8080->8080/tcp     recursing_northcutt
71734dea1499   tomcat:v2   "/bin/sh -c '/usr/lo…"   20 seconds ago   Up 19 seconds   0.0.0.0:49176->8080/tcp, :::49176->8080/tcp   quizzical_yalow

4.容器互联

[root@localhost tomcat]# docker run -d -P --name tomcat  tomcat:v2  //创建源容器
d160125c8e5373face71b29cb0dff715f6e2cbb5cd1a2f4f5acf374c28d8c09a
[root@localhost tomcat]# docker run -d -P --name tomcat2 --link tomcat:tomcat tomcat:v2  //创建接收容器
3fce1b17ec497ea776995b4bed527dca378d6f9f803b024cf1b4e925b46d84ed
[root@localhost tomcat]# docker exec -it tomcat2 /bin/bash    //进入容器测试
[root@3fce1b17ec49 /]# ping tomcat
PING tomcat (172.17.0.2) 56(84) bytes of data.
64 bytes from tomcat (172.17.0.2): icmp_seq=1 ttl=64 time=0.079 ms
64 bytes from tomcat (172.17.0.2): icmp_seq=2 ttl=64 time=0.101 ms
64 bytes from tomcat (172.17.0.2): icmp_seq=3 ttl=64 time=0.107 ms
^C
--- tomcat ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 1999ms
rtt min/avg/max/mdev = 0.079/0.095/0.107/0.016 ms
[root@3fce1b17ec49 /]#