Docker快速入门以及安装使用

川长思鸟来 2024-03-16 13:56 47阅读 0赞

### 1、Docker简介 ###

docker通过内核虚拟化技术（namespace及cgroups等）来提供容器的资源隔离与安全保障等，由于docker通过操作系统层的虚拟化实现隔离，所以docker容器在运行时，不需要类似虚拟机额外的操作系统开销，提供资源利用率。

### 2、Docker vs kvm ###

![f4a564e3036bb41a2cf6dc9413047593.png][]

![e41b3674c059374772f9418c3c41c0af.png][]

### 3、Docker组件 ###

镜像、容器、仓库

### 4、Docker安装 ###

[root@tiejiang ~]#tee /etc/yum.repos.d/docker.repo <<-'EOF'
    [dockerrepo]
    name=Docker Repository
    baseurl=https://yum.dockerproject.org/repo/main/centos/7/
    enabled=1
    gpgcheck=1
    gpgkey=https://yum.dockerproject.org/gpg
    EOF
    [root@tiejiang ~]# yum install docker-engine -y

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### 5、Docker基础操作 ###

[root@tiejiang ~]# systemctl enable docker.service
    Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
    [root@tiejiang ~]# systemctl start docker.service
    [root@tiejiang ~]# 
    [root@tiejiang ~]# docker pull centos  #拉取镜像
    [root@tiejiang ~]# docker pull daocloud.io/library/nginx

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有时候拉取速度很慢，采用国内源加速

[root@tiejiang ~]# vim /usr/lib/systemd/system/docker.service

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增加下面这行

EnvironmentFile=/etc/sysconfig/docker

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新建配置文件

[root@tiejiang ~]# vim /etc/sysconfig/docker

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在 [https://dashboard.daocloud.io/][https_dashboard.daocloud.io] 注册，然后点击加速器生成加速链接

`OPTIONS=--registry-mirror=curl -sSL https://get.daocloud.io/daotools/set_mirror.sh | sh -s`

[root@tiejiang ~]# docker search nginx  #搜索镜像
    
    [root@tiejiang ~]# docker images 
    
    REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
    
    centos              latest              0584b3d2cf6d        2 weeks ago         196.5 MB

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**导出镜像**

`[root@tiejiang ~]# docker save -o nginx.tar daocloud.io/library/nginx`

`[root@tiejiang ~]# docker save -o cnetos.tar centos`

**导入镜像**

`[root@tiejiang ~]# docker load --input cnetos.tar` 或者 `[root@docker ~]# docker load < cnetos.tar`

**删除镜像**

`[root@tiejiang ~]# docker rmi 0584b3d2cf6d （镜像ID）`

[root@tiejiang ~]# docker run centos /bin/echo "Hello world"
    Hello world
    [root@docker ~]# docker ps -a
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                     PORTS               NAMES
    5e381e68a385        centos              "/bin/echo 'Hello wor"   6 seconds ago       Exited (0) 5 seconds ago                       clever_lamarr
    
    [root@docker ~]# docker run --name mydocker -t -i centos /bin/bash
    [root@1a67f4c92b6e /]# 
    
    [root@1a67f4c92b6e /]# ps -ef
    UID         PID   PPID  C STIME TTY          TIME CMD
    root          1      0  0 18:56 ?        00:00:00 /bin/bash
    root         14      1  0 18:56 ?        00:00:00 ps -ef
    
    [root@1a67f4c92b6e /]# exit
    exit
    [root@tiejiang ~]# docker ps -a
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
    1a67f4c92b6e        centos              "/bin/bash"              12 minutes ago      Exited (0) 6 seconds ago                        mydocker
    5e381e68a385        centos              "/bin/echo 'Hello wor"   16 minutes ago      Exited (0) 16 minutes ago                       clever_lamarr
    
    [root@tiejiang ~]# docker run --name docker-demo -d centos /bin/bash    -d代表放入后台执行
    6c5a777467b9552714f9cd3322e677750e2b8b5b0bd2d81e79094ad560828a5e
    [root@tiejiang ~]# docker ps -a
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                      PORTS               NAMES
    6c5a777467b9        centos              "/bin/bash"              11 seconds ago      Exited (0) 11 seconds ago                       docker-demo
    1a67f4c92b6e        centos              "/bin/bash"              17 minutes ago      Exited (0) 4 minutes ago                        mydocker
    5e381e68a385        centos              "/bin/echo 'Hello wor"   21 minutes ago      Exited (0) 21 minutes ago                       clever_lamarr
    
    [root@tiejiang ~]# docker stop mydocker    停止容器
    [root@tiejiang ~]# docker start 1a67f4c92b6e   启动容器
    
    [root@tiejiang ~]# docker run -d --name mynginx daocloud.io/library/nginx
    225a9b0459630c62dcf2199d6244b16a74ad9412471abf0be03755768df3ae63
    [root@tiejiang ~]# 
    [root@tiejiang ~]# docker ps
    CONTAINER ID        IMAGE                       COMMAND                  CREATED             STATUS              PORTS               NAMES
    225a9b045963        daocloud.io/library/nginx   "nginx -g 'daemon off"   6 seconds ago   
        Up 5 seconds        80/tcp, 443/tcp     mynginx
    
    
    进入容器
    [root@tiejiang ~]# cat docker_in.sh 
    #!/bin/bash
    
    docker_in(){
    
      NAME_ID=$1
      PID=$(docker inspect --format "{
       { .State.Pid }}" $NAME_ID)
      nsenter -t $PID -m -u -i -n -p
    
    }
    
    
    docker_in $1

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### 6、docker网络 ###

[root@tiejiang ~]# docker run -d -P --name nginx-test1 daocloud.io/library/nginx
    9b1d36d40127fe2c84bbe7750802e435a817a15b4159b24fc49bfb1107a2cb74
    
    [root@tiejiang ~]# docker ps -l
    CONTAINER ID        IMAGE                       COMMAND                  CREATED             STATUS              PORTS                                           NAMES
    9b1d36d40127        daocloud.io/library/nginx   "nginx -g 'daemon off"   2 minutes ago       Up 2 minutes        0.0.0.0:32769->80/tcp, 0.0.0.0:32768->443/tcp   nginx-test1
    
    [root@tiejiang ~]# netstat -lntup|grep 32768
    tcp6       0      0 :::32768                :::*                    LISTEN      11213/docker-proxy  
    
    [root@tiejiang ~]# curl -I http://172.16.80.132:32769
    HTTP/1.1 200 OK
    Server: nginx/1.11.5
    Date: Thu, 24 Nov 2016 05:58:47 GMT
    Content-Type: text/html
    Content-Length: 612
    Last-Modified: Tue, 11 Oct 2016 15:03:01 GMT
    Connection: keep-alive
    ETag: "57fcff25-264"
    Accept-Ranges: bytes

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转换前

[root@tiejiang ~]# iptables -L -n
    Chain INPUT (policy ACCEPT)
    target     prot opt source               destination         
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            state RELATED,ESTABLISHED
    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            state NEW tcp dpt:22
    REJECT     all  --  0.0.0.0/0            0.0.0.0/0            reject-with icmp-host-prohibited
    
    Chain FORWARD (policy ACCEPT)
    target     prot opt source               destination         
    DOCKER-ISOLATION  all  --  0.0.0.0/0            0.0.0.0/0           
    DOCKER     all  --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
    REJECT     all  --  0.0.0.0/0            0.0.0.0/0            reject-with icmp-host-prohibited
    
    Chain OUTPUT (policy ACCEPT)
    target     prot opt source               destination         
    
    Chain DOCKER (1 references)
    target     prot opt source               destination         
    
    Chain DOCKER-ISOLATION (1 references)
    target     prot opt source               destination         
    RETURN     all  --  0.0.0.0/0            0.0.0.0/0

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转换后

[root@tiejiang ~]# docker run -d -P --name nginx-test1 daocloud.io/library/nginx
    42783cf5053639383004f82b9e72fe0223c7c028d2754b2d0f74429824715f05
    [root@tiejiang ~]# docker ps -l
    CONTAINER ID        IMAGE                       COMMAND                  CREATED             STATUS              PORTS                                           NAMES
    42783cf50536        daocloud.io/library/nginx   "nginx -g 'daemon off"   9 seconds ago       Up 7 seconds        0.0.0.0:32769->80/tcp, 0.0.0.0:32768->443/tcp   nginx-test1
    [root@tiejiang ~]# iptables -L -n
    Chain INPUT (policy ACCEPT)
    target     prot opt source               destination         
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            state RELATED,ESTABLISHED
    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            state NEW tcp dpt:22
    REJECT     all  --  0.0.0.0/0            0.0.0.0/0            reject-with icmp-host-prohibited
    
    Chain FORWARD (policy ACCEPT)
    target     prot opt source               destination         
    DOCKER-ISOLATION  all  --  0.0.0.0/0            0.0.0.0/0           
    DOCKER     all  --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            ctstate RELATED,ESTABLISHED
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           
    REJECT     all  --  0.0.0.0/0            0.0.0.0/0            reject-with icmp-host-prohibited
    
    Chain OUTPUT (policy ACCEPT)
    target     prot opt source               destination         
    
    Chain DOCKER (1 references)
    target     prot opt source               destination         
    ACCEPT     tcp  --  0.0.0.0/0            172.17.0.2           tcp dpt:443
    ACCEPT     tcp  --  0.0.0.0/0            172.17.0.2           tcp dpt:80
    
    Chain DOCKER-ISOLATION (1 references)
    target     prot opt source               destination         
    RETURN     all  --  0.0.0.0/0            0.0.0.0/0           
    
    [root@tiejiang ~]# sh docker_in.sh nginx-test1
    root@42783cf50536:/# 
    root@42783cf50536:/# 
    root@42783cf50536:/# ip addr
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default 
        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
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    4: eth0: <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 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::42:acff:fe11:2/64 scope link 
           valid_lft forever preferred_lft forever

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### 7、Docker数据存储 ###

[root@tiejiang ~]# docker run -d --name nginx-volume-test1 -v /data daocloud.io/library/nginx
    88b24d79a4f3b021325592ceac20e86291166d675b213d60db017548c4d9d960
    
    [root@tiejiang ~]# sh docker_in.sh nginx-volume-test1
    root@88b24d79a4f3:/# cd /data/
    root@88b24d79a4f3:/data# ls
    root@88b24d79a4f3:/data# touch hehe
    root@88b24d79a4f3:/data# ls -l      
    total 0
    -rw-r--r-- 1 root root 0 Nov 24 06:30 hehe
    
    [root@tiejiang ~]# cd /var/lib/docker/
    [root@tiejiang docker]# ll
    total 32
    drwx------ 6 root root 4096 Nov 24 14:28 containers
    drwx------ 5 root root 4096 Nov 24 02:05 devicemapper
    drwx------ 3 root root 4096 Nov 24 01:20 image
    drwxr-x--- 3 root root 4096 Nov 24 01:20 network
    drwx------ 2 root root 4096 Nov 24 01:20 swarm
    drwx------ 2 root root 4096 Nov 24 10:09 tmp
    drwx------ 2 root root 4096 Nov 24 01:20 trust
    drwx------ 3 root root 4096 Nov 24 14:28 volumes
    [root@tiejiang docker]# cd volumes/
    [root@tiejiang volumes]# ls
    4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60  metadata.db
    [root@tiejiang volumes]# cd 4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60/
    [root@tiejiang 4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60]# ls
    _data
    [root@tiejiang 4c60775f938a840e5484aee9088bc612977c25a01f5bd164690d94c962e66e60]# cd _data/    容器内的文件实际在物理机上面的的保存目录
    [root@tiejiang _data]# ls
    hehe
    
    [root@tiejiang ~]# docker run -d --name nginx-volume-test2 -v /data/mysql:/mysql daocloud.io/library/nginx   
    f7278ce9bd88c26a0c5aaefcb2b39f1f9df0066bc94edb7a530213815e166f5e
    
    #-v /data/mysql:/mysql  表示把物理机的/data/mysql目录挂载到容器内的/mysql目录下面
    
    
    [root@tiejiang ~]# docker run -d --name nginx-volumes -v /data/mysql:/mysql daocloud.io/library/nginx
    28c616e44352fc4eafeb2f87dbbb7b6eb9df447235afe027034efa96df1c5071
    
    [root@tiejiang ~]# 
    [root@tiejiang ~]# docker run -d --name web-node1 --volumes-from nginx-volumes daocloud.io/library/nginx
    0f022ce56e8b800cb1a4ac76bb8a326d42e198093146e8661ad3ac8925ad317d
    [root@tiejiang ~]# 
    [root@tiejiang ~]# docker run -d --name web-node2 --volumes-from nginx-volumes daocloud.io/library/nginx
    03d5e88c15f6604eeee2b8af500b8f356ba69adc34710f3c19b813530f19dc3d

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[f4a564e3036bb41a2cf6dc9413047593.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/65e05cf8a399419b886a9e82c3c385b3.png
[e41b3674c059374772f9418c3c41c0af.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/08a76b27b3e74be693823a709c80d882.png
[https_dashboard.daocloud.io]: https://dashboard.daocloud.io/