Docker Hub

Docker Hub是一个基于云的注册服务，它允许您链接到代码库，构建并测试您的映像，存储手动推送的映像，并链接到Docker Cloud，以便您可以将映像部署到您的主机。

它为容器映像发现、分发和变更管理、用户和团队协作以及整个开发流程中的工作流自动化提供了一个集中的资源。

Docker Hub提供以下主要功能:

• 图像存储库
• 从社区和官方图书馆查找和提取图像，从您有权访问的私人图像库中管理、推送和提取图像。
• 自动化构建
• 当您对源代码库进行更改时，自动创建新的映像。
• Web手册
• 作为自动化构建的一个特性，Webhooks允许您在成功推送存储库之后触发操作。
• 组织
• 创建工作组来管理对图像存储库的访问。
• GitHub和Bitbucket集成
• 将中心和Docker图像添加到您当前的工作流程中。

docker镜像的获取

要从远程注册表(如您自己的Docker注册表)获取Docker映像并将其添加到您的本地系统，请使用docker pull命令:

docker pull (registry)[:(port)]/(namespace)/:(tag)

是在TCP上提供docker分发服务的主机(默认值:5000)

并在注册处识别由控制的特定图像

• 有些注册表还支持raw对于那些，是可选的
• 但是，当包含它时，提供的额外层级对于区分具有相同

层次结构的附加级别

镜像的生成

镜像的生成途径：

• Dockerfile
• 基于容器制作
• Docker Hub automated builds

基于容器制作镜像

根据容器的更改创建新图像

使用方法：

docker commit [OPTIONS] CONTAINER [REPOSITORY[:TAG]]

[root@localhost ~]# docker pull busybox

[root@localhost ~]# docker run --name bi -it busybox
/ # ls
bin   dev   etc   home  proc  root  sys   tmp   usr   var
/ # mkdir data
/ # ls
bin   data  dev   etc   home  proc  root  sys   tmp   usr   var
/ # echo 'nihao' > data/index.html
/ # cat data/index.html 
nihao

在创建镜像时，我们不能关闭容器，必须使其处于运行状态，所以我们必须要另起一个终端，然后执行

[root@localhost ~]# docker commit -p bi
sha256:b726393438ac33e9f2fb6701a64b4f982e432c4c75534538de6ac6d0273ce1f1
[root@localhost ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
<none>       <none>    b726393438ac   7 seconds ago   1.24MB
busybox      latest    beae173ccac6   7 months ago    1.24MB
httpd        latest    dabbfbe0c57b   7 months ago    144MB
centos       latest    5d0da3dc9764   10 months ago   231MB
[root@localhost ~]# docker tag b726393438ac luojialong123/v1
[root@localhost ~]# docker images 
REPOSITORY         TAG       IMAGE ID       CREATED              SIZE
luojialong123/v1   latest    b726393438ac   About a minute ago   1.24MB
busybox            latest    beae173ccac6   7 months ago         1.24MB
httpd              latest    dabbfbe0c57b   7 months ago         144MB
centos             latest    5d0da3dc9764   10 months ago        231MB

登录

[root@localhost ~]# docker login 
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: luojialong123
Password: 
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store

Login Succeeded

[root@localhost ~]# docker push luojialong123/v1
Using default tag: latest
The push refers to repository [docker.io/luojialong123/v1]
681c623b60a6: Pushed 
01fd6df81c8e: Mounted from library/busybox 
latest: digest: sha256:8050cdd117871dda41cd5f5209f84559954a8efb80ae4215abcb4868890cd71b size: 734

使用新生成的镜像创建容器

[root@localhost ~]# docker run --name t1 -it luojialong123/v1
/ # ls data/
index.html
/ # cat data/index.html 
nihao

由此可见，新生成的镜像中是包含了新增的内容的，但是此时有一个问题，那就是容器默认要启动的进程是什么？在这里，默认情况下是启动的sh进程，但我们是要启动一个http站点，所以我们要在创建镜像时将容器默认启动的进程设为httpd，这样一来我们就可以通过新生成的镜像来快速构建一个简单的http站点了。

使用docker inspect命令查看b1容器启动的默认进程是什么

[root@localhost ~]# docker inspect bi

"Cmd": [
                "sh"
"Gateway": "172.17.0.1",
"IPAddress": "172.17.0.2",

重新生成镜像并上传

[root@localhost ~]# docker commit -a 'sean <sean1002@126.com>' -c 'CMD ["/bin/httpd","-f","-h","/data"]' -p  bi luojialong123/v2
sha256:454d18d47b5d49afed0b5ce580862a5aff3e11e381d0a72e9fbbfbf85644f8d6

[root@localhost ~]# docker push luojialong123/v2
Using default tag: latest
The push refers to repository [docker.io/luojialong123/v2]
681c623b60a6: Mounted from luojialong123/v1 
01fd6df81c8e: Mounted from luojialong123/v1 
latest: digest: sha256:5852124f7a55fa90a76a21e0bee0fda36ff1443d1907d68029a0ee0caca99cca size: 734

使用新生成的镜像创建容器

[root@localhost ~]# docker run --name t2 -d luojialong123/v2
b55e354f84c13f427c5acc5bdfcdede78705501aab1cb2c742d3e1ff05542013
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE              COMMAND                  CREATED          STATUS                    PORTS     NAMES
b55e354f84c1   luojialong123/v2   "/bin/httpd -f -h /d…"   16 seconds ago   Up 13 seconds                       t2

使用docker inspect命令查看t2容器启动的默认进程是什么，以及其IP地址，然后用curl命令访问该IP，看是否能访问到网页

[root@localhost ~]# curl 172.17.0.4
nihao

镜像的导入与导出

假如有2台主机，我们在主机1上做了一个镜像，主机2想用这个镜像怎么办呢？

我们可以在主机1上push镜像到镜像仓库中，然后在主机2上pull把镜像拉下来使用，这种方式就显得比较麻烦，假如我只是测试用的，在一台主机上做好镜像后在另一台主机上跑一下就行了，没必要推到仓库上然后又把它拉到本地来。

此时我们可以在已有镜像的基础上把镜像打包成一个压缩文件，然后拷贝到另一台主机上将其导入，这就是镜像的导入和导出功能。

docker中我们使用docker save进行导出，使用docker load进行导入。

在已生成镜像的主机上执行docker save导出镜像

[root@localhost ~]# docker save -o busybox  luojialong123/v1
[root@localhost ~]# ls
anaconda-ks.cfg  busybox

在另一台服务器上查看并导入v1

[root@localhost ~]# docker images
REPOSITORY         TAG       IMAGE ID       CREATED          SIZE
luojialong123/v2   latest    454d18d47b5d   24 minutes ago   1.24MB
busybox            latest    beae173ccac6   7 months ago     1.24MB
httpd              latest    dabbfbe0c57b   7 months ago     144MB
centos             latest    5d0da3dc9764   10 months ago    231MB

[root@localhost ~]# docker load -i busybox 
Loaded image: luojialong123/v1:latest
[root@localhost ~]# docker images
REPOSITORY         TAG       IMAGE ID       CREATED          SIZE
luojialong123/v2   latest    454d18d47b5d   25 minutes ago   1.24MB
luojialong123/v1   latest    b726393438ac   43 minutes ago   1.24MB
busybox            latest    beae173ccac6   7 months ago     1.24MB
httpd              latest    dabbfbe0c57b   7 months ago     144MB
centos             latest    5d0da3dc9764   10 months ago    231MB

练习题

查找
[root@localhost ~]# docker search centos
NAME                                         DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
centos                                       The official build of CentOS.                   7271      [OK]       
拉取centos
[root@localhost ~]# docker pull centos
Using default tag: latest
latest: Pulling from library/centos
Digest: sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
Status: Image is up to date for centos:latest
docker.io/library/centos:latest
查看centos镜像[root@localhost ~]# docker images
REPOSITORY         TAG       IMAGE ID       CREATED         SIZE
luojialong123/v2   latest    454d18d47b5d   23 hours ago    1.24MB
luojialong123/v1   latest    b726393438ac   23 hours ago    1.24MB
busybox            latest    beae173ccac6   7 months ago    1.24MB
httpd              latest    dabbfbe0c57b   7 months ago    144MB
centos             latest    5d0da3dc9764   10 months ago   231MB
创建centos容器
[root@localhost ~]# docker run -it --name centos centos /bin/bash
[root@bdb23a6fee64 /]# ls
bin  etc   lib	  lost+found  mnt  proc  run   srv  tmp  var
dev  home  lib64  media       opt  root  sbin  sys  usr

配置yum源
[root@bdb23a6fee64 /]# rm -rf /etc/yum.repos.d/*

[root@bdb23a6fee64 /]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2495  100  2495    0     0   5447      0 --:--:-- --:--:-- --:--:--  5435

[root@bdb23a6fee64 /]# sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

[root@bdb23a6fee64 /]# yum install -y https://mirrors.aliyun.com/epel/epel-release-latest-8.noarch.rpm
过程省略...
Complete!

[root@bdb23a6fee64 src]#wget https://downloads.apache.org/apr/apr-1.6.5.tar.bz2
[root@bdb23a6fee64 src]#wget https://downloads.apache.org/apr/apr-util-1.6.1.tar.bz2
[root@bdb23a6fee64 src]#wget https://downloads.apache.org/httpd/httpd-2.4.54.tar.bz2

安装apr
[root@bdb23a6fee64 src]# yum groups mark install "Development Tools"
Is this ok [y/N]: y
Complete!

[root@bdb23a6fee64 src]# useradd -r apache 

[root@bdb23a6fee64 src]# yum -y install openssl-devel pcre-devel expat-devel libtool

[root@bdb23a6fee64 src]# tar xf apr-1.6.5.tar.bz2 
[root@bdb23a6fee64 apr-1.6.5]# cd apr-1.6.5
[root@bdb23a6fee64 apr-1.6.5]# vim configure
#    $RM "$cfgfile"  在行首添加#

[root@bdb23a6fee64 apr-1.6.5]# ./configure --prefix=/usr/local/apr
[root@bdb23a6fee64 apr-1.6.5]# make && make install

安装apr-util
[root@bdb23a6fee64 ~]# cd /usr/src/
[root@bdb23a6fee64 src]# tar xf apr-util-1.6.1.tar.bz2 
[root@bdb23a6fee64 apr-util-1.6.1]# ./configure --prefix=/usr/local/apr-util --with-apr=/usr/local/apr
[root@bdb23a6fee64 apr-util-1.6.1]# make && make install

安装httpd
[root@bdb23a6fee64 apr-util-1.6.1]# cd /usr/src/
[root@bdb23a6fee64 src]# tar xf httpd-2.4.54.tar.bz2 
[root@bdb23a6fee64 src]# cd httpd-2.4.54
[root@bdb23a6fee64 httpd-2.4.54]# ./configure --prefix=/usr/local/apache --enable-so --enable-ssl --enable-cgi --enable-rewrite --with-zlib --with-pcre --with-apr=/usr/local/apr --with-apr-util=/usr/local/apr-util/ --enable-modules=most --enable-mpms-shared=all --with-mpm=prefork
[root@bdb23a6fee64 httpd-2.4.54]# make && make install

编辑脚本
[root@bdb23a6fee64 httpd-2.4.54]# cd
[root@bdb23a6fee64 ~]# vim httpd.sh

#!/bin/bash
/usr/local/apache/bin/apachectl
sleep 5d
[root@bdb23a6fee64 ~]# chmod +x httpd.sh

在另一个终端生成镜像
[root@localhost ~]# docker commit -a 'frices <frices 1@2.com>' -c 'CMD ["./httpd.sh"]' -p centos frices/centos:httpd
sha256:db99d7691ae9459d43c491658edc75012fcd0bf643ff5b8f9f0b448ccd15af93
[root@localhost ~]# docker images
REPOSITORY      TAG       IMAGE ID       CREATED          SIZE
frices/centos   httpd     db99d7691ae9   10 seconds ago   730MB
centos          latest    5d0da3dc9764   10 months ago    231MB



用新生成的镜像创建容器

[root@localhost ~]# docker run -d -it --name centos-httpd frices/centos:httpd
bce83cae524d67155171df93d3970912bc5715c2c896f7f82c46aebb06d05f76
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE                 COMMAND        CREATED              STATUS              PORTS     NAMES
bce83cae524d   frices/centos:httpd   "./httpd.sh"   About a minute ago   Up About a minute             centos-httpd
bdb23a6fee64   centos                "/bin/bash"    3 hours ago          Up 3 hours 

[root@localhost ~]# docker inspect centos-httpd

        "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.3",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:03",
            "Networks": {
[root@localhost ~]# curl 172.17.0.3
<html><body><h1>It works!</h1></body></html>

配置端口映射
[root@localhost ~]# docker run -d -it --name centos-httpd2 -p 80:80 frices/centos:httpd
d2d1700e3a571f4a7d61d116520408774a1a375eecf1db679e3d54cd4345ad80
[root@localhost ~]# 
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE                 COMMAND        CREATED         STATUS         PORTS                               NAMES
d2d1700e3a57   frices/centos:httpd   "./httpd.sh"   7 seconds ago   Up 6 seconds   0.0.0.0:80->80/tcp, :::80->80/tcp   centos-httpd2
bce83cae524d   frices/centos:httpd   "./httpd.sh"   6 minutes ago   Up 6 minutes                                       centos-httpd
bdb23a6fee64   centos                "/bin/bash"    3 hours ago     Up 3 hours                                         centos
[root@localhost ~]# ss -antl 
State     Recv-Q    Send-Q       Local Address:Port       Peer Address:Port   Process   
LISTEN    0         128                0.0.0.0:80              0.0.0.0:*                
LISTEN    0         128                0.0.0.0:22              0.0.0.0:*                
LISTEN    0         128                   [::]:80                 [::]:*                
LISTEN    0         128                   [::]:22                 [::]:*