01-docker之安装手册

docker安装

在Linux centOS7上面安装docker。操作如下（参考官网给出的安装手册：https://docs.docker.com/engine/install/centos/）

1.删除本机docker

yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-engine

2.安装docker

yum install -y yum-utils
yum-config-manager \
    --add-repo \
    https://download.docker.com/linux/centos/docker-ce.repo
 yum install docker-ce docker-ce-cli containerd.io

3.启动docker

systemctl start docker

4.拉取hello-world

docker pull hello-world:latest

5.查看镜像

docker images

6.启动hello-world

docker run hello-world

7.查看容器

docker ps

8.配置中国的镜像仓库，加快下载速度。使用阿里云的镜像仓库

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://po7p45t1.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

docker架构图

image.png

docker	java	备注
Registry	maven	参考存放各种镜像文件
Images	类	镜像文件和类差不多
Containers	对象	容器和对象差不多，容器是由镜像创建的

Images-镜像

1.添加一个镜像

创建一个centos的镜像

1.搜索centos的镜像
https://hub.docker.com/

2.使用命令：
docker pull centos:centos7

3.检查docker镜像
[root@VM-0-4-centos ~]# docker images
REPOSITORY    TAG       IMAGE ID       CREATED        SIZE
hello-world   latest    feb5d9fea6a5   6 months ago   13.3kB
centos        centos7   eeb6ee3f44bd   7 months ago   204MB

4.将镜像运行成容器 -it表示创建一个带交互的终端
[root@VM-0-4-centos ~]# docker run -it centos:centos7
[root@d998f693710e /]# ls
anaconda-post.log  bin  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var

5.检查运行中的容器
[root@VM-0-4-centos ~]# docker ps
CONTAINER ID   IMAGE            COMMAND       CREATED          STATUS          PORTS     NAMES
d998f693710e   centos:centos7   "/bin/bash"   18 seconds ago   Up 17 seconds             inspiring_galileo

6.使用exit退出终端，退出的同时会关闭容器
[root@d998f693710e /]# exit
exit

2.搜索镜像

docker search xxx

[root@VM-0-4-centos ~]# docker search centos
NAME                              DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
centos                            The official build of CentOS.                   7106      [OK]       
centos/systemd                    systemd enabled base container.                 108                  [OK]
centos/mysql-57-centos7           MySQL 5.7 SQL database server                   93                   
centos/postgresql-96-centos7      PostgreSQL is an advanced Object-Relational …   45                   
centos/httpd-24-centos7           Platform for running Apache httpd 2.4 or bui…   44                   
centos/python-35-centos7          Platform for building and running Python 3.5…   39                   
centos/php-56-centos7             Platform for building and running PHP 5.6 ap…   34                   
centos/mysql-56-centos7           MySQL 5.6 SQL database server                   22                   
centos/postgresql-10-centos7      PostgreSQL is an advanced Object-Relational …   19                   
kasmweb/centos-7-desktop          CentOS 7 desktop for Kasm Workspaces            18                   
centos/nginx-112-centos7          Platform for running nginx 1.12 or building …   16                   
centos/mariadb-101-centos7        MariaDB 10.1 SQL database server                13                   
centos/nginx-18-centos7           Platform for running nginx 1.8 or building n…   13                   
centos/mongodb-36-centos7         MongoDB NoSQL database server                   8                    
centos/redis-32-centos7           Redis in-memory data structure store, used a…   6                    
centos/mariadb-102-centos7        MariaDB 10.2 SQL database server                6                    
continuumio/centos5_gcc5_base                                                     3                    
centos/ruby-25-centos7            Platform for building and running Ruby 2.5 a…   3                    
kasmweb/core-centos-7             CentOS 7 base image for Kasm Workspaces         2                    
bitnami/centos-base-buildpack     Centos base compilation image                   0                    [OK]
bitnami/centos-extras-base                                                        0                    
datadog/centos-i386                                                               0                    
ibmcom/fhe-toolkit-centos         The IBM Fully Homomorphic Encryption (FHE) T…   0                    
centos/nginx-110-centos7          Platform for running nginx 1.10 or building …   0                    
ibmcom/fhe-toolkit-centos-amd64   The IBM Fully Homomorphic Encryption (FHE) T…   0                    
[root@VM-0-4-centos ~]# 

使用docker仓库搜索，可以指定tag来下载指定版本

https://hub.docker.com/

3.拉取镜像

docker pull centos:centos7
// xxx:xxx 指定下载tag
比如拉取mysql镜像
docker pull mysql:8.0

4.删除镜像

删除镜像前需要停止该镜像的容器，并且删除
docker stop hello-world
清除所有停止的容器
docker container prune
或者删除容器
docker rm 容器id
删除镜像
docker rmi hello-world

5.生成镜像

了解dockerfile文件

实验：基于centos7创建一个包含vim命令的我的centos7

实验：基于Tomcat创建一个含有首页的Tomcat

1.拉取Tomcat镜像
docker pull tomcat
2.启动镜像，生成Tomcat容器。以容器终端的方式启动Tomcat
docker run -it -p 8888:8080 tomcat
3.访问首页

4.重新打开一个终端，并且创建一个首页
docker exec -it 容器ID /bin/bash
root@6e01e405ba82:/usr/local/tomcat# cd webapps
root@6e01e405ba82:/usr/local/tomcat/webapps# ls
root@6e01e405ba82:/usr/local/tomcat/webapps# mkdir ROOT
root@6e01e405ba82:/usr/local/tomcat/webapps# echo 'hello docker' > index.html
root@6e01e405ba82:/usr/local/tomcat/webapps# mv index.html ROOT/

5.将当前容器build成自己的镜像
docker commit -a='cjxz' -m='add index.html' 容器ID cjxz/tomcat:1.0
[root@VM-0-4-centos ~]# docker commit -a='cjxz' -m='add index.html' 6e01e405ba82  cjxz/tomcat:1.0
sha256:6217c92b3c1caf7f985df4cd38420682104672b3096561b41a08d55cb8b44b03
[root@VM-0-4-centos ~]# docker images -a
REPOSITORY    TAG       IMAGE ID       CREATED         SIZE
cjxz/tomcat   1.0       6217c92b3c1c   9 seconds ago   680MB
tomcat        latest    fb5657adc892   4 months ago    680MB
mysql         8.0       3218b38490ce   4 months ago    516MB
centos        centos7   eeb6ee3f44bd   7 months ago    204MB
[root@VM-0-4-centos ~]# 

这样我们可以直接通过cjxz/tomcat创建一个新的容器，并且容器携带index.html

Containers-容器

镜像被run之后就成为容器

容器通过commit又能够变成镜像

Registry-镜像仓库

查找地址：docker hub