我要评论dockerfile 是用来构建docker镜像的文件！命令参数脚本！
构建步骤：
- 编写一个dockerfile 文件
- docker build 构建成一个镜像
- docker run 运行镜像
- docker push 发布镜像（dockerhub、阿里云镜像仓库）
# 以contes为例 查看 dockerhub 上 contes 的 dockerfile 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="20200809" \ org.opencontainers.image.title="centos base image" \ org.opencontainers.image.vendor="centos" \ org.opencontainers.image.licenses="gpl-2.0-only" \ org.opencontainers.image.created="2020-08-09 00:00:00+01:00" cmd ["/bin/bash"]
dockerfile构建过程
基础知识：
- 每个保留关键字（指令）都必须是大写字母
- 执行顺序从上到下顺序执行
- 表示注释
- 每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镜像逐渐成为企业交付的标准！
dockerfile：构建镜像，定义了一切的步骤，源代码；
dockerimages：通过dockerfile构建生成的一个镜像，这个镜像就是我们最终发布和运行的产品！
docker容器：容器就是镜像运行起来提供服务！
dockerfile的指令
from # 基础镜像 maintainer # 镜像是谁写的 姓名 + 邮箱 run # 镜像构建的时候需要运行的命令 add # 步骤 eg:tomcat镜像---》放入tomcat的压缩包！添加内容 workdir # 镜像的工作目录 volume # 挂载的目录位置 expost # 暴露端口配置 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 onbuild # 当构建一个被继承的 dockerfile ，这个时候就会运行 onbuild 的指令，触发指令 copy # 类似add，将我们的文件拷贝到镜像中 env # 构建的时候设置环境变量
实战测试
docker hub 中 99% 的镜像都是从 from scratch 这个基础镜像过来的 ，然后配置我们需要的软件和配置来进行构建
创建一个自己的centos
# 1、编写dockerfile的文件
from centos
# 作者信息
maintainer yinxiaodong<m15010969094@163.com>
# 配置环境变量
env mypath /user/local
# 指定镜像的工作目录
workdir $mypath
run yum install -y vim
run yum install -y net-tools
# 暴露80端口
expose 80
cmd echo $mypath
cmd echo "---------end--------"
cmd /bin/bash
# 2、通过文件构建镜像
# 命令 docker build -f dockerfile文件路径 -t 镜像名:版本号 .
[root@localhost dockerfile]# docker build -f mydockerfile-centos -t mycentos:0.1 .
sending build context to docker daemon 2.048kb
step 1/9 : from centos
---> 0d120b6ccaa8
step 2/9 : maintainer yinxiaodong<m15010969094@163.com>
---> running in f79b12ffb083
removing intermediate container f79b12ffb083
---> 8ee53d3f7a65
step 3/9 : env mypath /user/local
---> running in 659a2c96d5f7
removing intermediate container 659a2c96d5f7
---> 59ab131ef44c
step 4/9 : workdir $mypath
---> running in 0b4b8f9c65bb
removing intermediate container 0b4b8f9c65bb
---> 408b06671488
step 5/9 : run yum install -y net-tools
---> running in 151f81148a87
centos-8 - appstream 118 kb/s | 5.8 mb 00:50
centos-8 - base 218 kb/s | 2.2 mb 00:10
centos-8 - extras 1.8 kb/s | 7.3 kb 00:04
dependencies resolved.
================================================================================
package architecture version repository size
================================================================================
installing:
net-tools x86_64 2.0-0.51.20160912git.el8 baseos 323 k
transaction summary
================================================================================
install 1 package
total download size: 323 k
installed size: 1.0 m
downloading packages:
net-tools-2.0-0.51.20160912git.el8.x86_64.rpm 219 kb/s | 323 kb 00:01
--------------------------------------------------------------------------------
total 66 kb/s | 323 kb 00:04
warning: /var/cache/dnf/baseos-f6a80ba95cf937f2/packages/net-tools-2.0-0.51.20160912git.el8.x86_64.rpm: header v3 rsa/sha256 signature, key id 8483c65d: nokey
centos-8 - base 162 kb/s | 1.6 kb 00:00
importing gpg key 0x8483c65d:
userid : "centos (centos official signing key) <security@centos.org>"
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 : net-tools-2.0-0.51.20160912git.el8.x86_64 1/1
running scriptlet: net-tools-2.0-0.51.20160912git.el8.x86_64 1/1
verifying : net-tools-2.0-0.51.20160912git.el8.x86_64 1/1
installed:
net-tools-2.0-0.51.20160912git.el8.x86_64
complete!
removing intermediate container 151f81148a87
---> c0a0546c9b2a
step 6/9 : expose 80
---> running in 42000936515d
removing intermediate container 42000936515d
---> fe68114ecf3f
step 7/9 : cmd echo $mypath
---> running in c393fc53a354
removing intermediate container c393fc53a354
---> a6924276bf90
step 8/9 : cmd echo "---------end--------"
---> running in 5994de56f0a1
removing intermediate container 5994de56f0a1
---> a8ba0ebb3770
step 9/9 : cmd /bin/bash
---> running in d1fa2d436363
removing intermediate container d1fa2d436363
---> 41bb76be4884
successfully built 41bb76be4884
successfully tagged mycentos:0.1
[root@localhost dockerfile]# docker images
repository tag image id created size
mycentos 0.1 41bb76be4884 7 seconds ago 246mb
centos 1.0 d840628c30a9 6 hours ago 215mb
centos latest 0d120b6ccaa8 2 days ago 215mb
# 启动 mycentos 使用 ifconfig 命令查看ip信息
[root@localhost dockerfile]# docker run -it mycentos:0.1
[root@494c2bc72263 local]# ifconfig
eth0: flags=4163<up,broadcast,running,multicast> mtu 1500
inet 172.17.0.3 netmask 255.255.0.0 broadcast 172.17.255.255
ether 02:42:ac:11:00:03 txqueuelen 0 (ethernet)
rx packets 6 bytes 516 (516.0 b)
rx errors 0 dropped 0 overruns 0 frame 0
tx packets 0 bytes 0 (0.0 b)
tx errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<up,loopback,running> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
loop txqueuelen 1000 (local loopback)
rx packets 0 bytes 0 (0.0 b)
rx errors 0 dropped 0 overruns 0 frame 0
tx packets 0 bytes 0 (0.0 b)
tx errors 0 dropped 0 overruns 0 carrier 0 collisions 0
# 查看所在目录 /user/local 正是我们在dockerfile中指定的目录
[root@494c2bc72263 local]# pwd
/user/local
查看镜像的构建历史记录
# 命令 docker history 镜像id [root@localhost ~]# docker history 41bb76be4884 image created created by size comment 41bb76be4884 16 minutes ago /bin/sh -c #(nop) cmd ["/bin/sh" "-c" "/bin… 0b a8ba0ebb3770 16 minutes ago /bin/sh -c #(nop) cmd ["/bin/sh" "-c" "echo… 0b a6924276bf90 16 minutes ago /bin/sh -c #(nop) cmd ["/bin/sh" "-c" "echo… 0b fe68114ecf3f 16 minutes ago /bin/sh -c #(nop) expose 80 0b c0a0546c9b2a 16 minutes ago /bin/sh -c yum install -y net-tools 31.3mb 408b06671488 17 minutes ago /bin/sh -c #(nop) workdir /user/local 0b 59ab131ef44c 17 minutes ago /bin/sh -c #(nop) env mypath=/user/local 0b 8ee53d3f7a65 17 minutes ago /bin/sh -c #(nop) maintainer yinxiaodong<m1… 0b 0d120b6ccaa8 2 days ago /bin/sh -c #(nop) cmd ["/bin/bash"] 0b <missing> 2 days ago /bin/sh -c #(nop) label org.label-schema.sc… 0b <missing> 2 days ago /bin/sh -c #(nop) add file:538afc0c5c964ce0d… 215mb
我们平时拿到一个镜像，可以研究一下它是怎么做的---->docker history 镜像id
cmd 和 entrypoint 的区别
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的文件 [root@localhost dockerfile]# cat dockerfile-cmd-test from centos cmd ["ls","-a"] # 根据 dockerfile 构建镜像 [root@localhost dockerfile]# docker build -f dockerfile-cmd-test -t testcmd:0.1 . sending build context to docker daemon 3.072kb step 1/2 : from centos ---> 0d120b6ccaa8 step 2/2 : cmd ["ls","-a"] ---> running in b3f8ba72222b removing intermediate container b3f8ba72222b ---> 561e47f88730 successfully built 561e47f88730 successfully tagged testcmd:0.1 # 构建成功 # 查看镜像 [root@localhost dockerfile]# docker images repository tag image id created size testcmd 0.1 561e47f88730 6 seconds ago 215mb centos latest 0d120b6ccaa8 2 days ago 215mb # 启动镜像 发现ls -a命令生效 [root@localhost dockerfile]# docker run -it testcmd:0.1 . .dockerenv dev home lib64 media opt root sbin sys usr .. bin etc lib lost+found mnt proc run srv tmp var # 启动命令中 追加一个 -l, 我们期望的是 ls -a -l,但是 报错，这里将 ls -a 替换成了 -l，最终的命令是 -l 所以报错。 [root@localhost dockerfile]# docker run -it 561e47f88730 -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. # 将启动命令替换成 docker run -it testcmd:0.1 ls -al， 成功打印详细信息; [root@localhost dockerfile]# docker run -it testcmd:0.1 ls -al total 0 drwxr-xr-x. 1 root root 6 aug 13 08:20 . drwxr-xr-x. 1 root root 6 aug 13 08:20 .. -rwxr-xr-x. 1 root root 0 aug 13 08:20 .dockerenv lrwxrwxrwx. 1 root root 7 may 11 2019 bin -> usr/bin drwxr-xr-x. 5 root root 360 aug 13 08:20 dev drwxr-xr-x. 1 root root 66 aug 13 08:20 etc drwxr-xr-x. 2 root root 6 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 drwx------. 2 root root 6 aug 9 21:40 lost+found drwxr-xr-x. 2 root root 6 may 11 2019 media drwxr-xr-x. 2 root root 6 may 11 2019 mnt drwxr-xr-x. 2 root root 6 may 11 2019 opt dr-xr-xr-x. 123 root root 0 aug 13 08:20 proc dr-xr-x---. 2 root root 162 aug 9 21:40 root drwxr-xr-x. 11 root root 163 aug 9 21:40 run lrwxrwxrwx. 1 root root 8 may 11 2019 sbin -> usr/sbin drwxr-xr-x. 2 root root 6 may 11 2019 srv dr-xr-xr-x. 13 root root 0 aug 11 09:58 sys drwxrwxrwt. 7 root root 145 aug 9 21:40 tmp drwxr-xr-x. 12 root root 144 aug 9 21:40 usr drwxr-xr-x. 20 root root 262 aug 9 21:40 var # 测试二：现在我们把 dockerfile 中 cmd 替换成 entrypoint 后重新构建，运行 看看结果 [root@localhost dockerfile]# cat dockerfile-cmd-test from centos entrypoint ["ls","-a"] # 重新构建镜像 [root@localhost dockerfile]# docker build -f dockerfile-cmd-test -t testcmd:0.2 . sending build context to docker daemon 3.072kb step 1/2 : from centos ---> 0d120b6ccaa8 step 2/2 : entrypoint ["ls","-a"] ---> running in c634ca09fabe removing intermediate container c634ca09fabe ---> 52d295395f08 successfully built 52d295395f08 successfully tagged testcmd:0.2 # 查看镜像 [root@localhost dockerfile]# docker images repository tag image id created size testcmd 0.2 52d295395f08 7 seconds ago 215mb testcmd 0.1 561e47f88730 12 minutes ago 215mb centos latest 0d120b6ccaa8 2 days ago 215mb # 运行testcmd：0.2镜像 并追加 -l ,发现 打印出了详细信息 [root@localhost dockerfile]# docker run -it testcmd:0.2 -l total 0 drwxr-xr-x. 1 root root 6 aug 13 08:17 . drwxr-xr-x. 1 root root 6 aug 13 08:17 .. -rwxr-xr-x. 1 root root 0 aug 13 08:17 .dockerenv lrwxrwxrwx. 1 root root 7 may 11 2019 bin -> usr/bin drwxr-xr-x. 5 root root 360 aug 13 08:17 dev drwxr-xr-x. 1 root root 66 aug 13 08:17 etc drwxr-xr-x. 2 root root 6 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 drwx------. 2 root root 6 aug 9 21:40 lost+found drwxr-xr-x. 2 root root 6 may 11 2019 media drwxr-xr-x. 2 root root 6 may 11 2019 mnt drwxr-xr-x. 2 root root 6 may 11 2019 opt dr-xr-xr-x. 121 root root 0 aug 13 08:17 proc dr-xr-x---. 2 root root 162 aug 9 21:40 root drwxr-xr-x. 11 root root 163 aug 9 21:40 run lrwxrwxrwx. 1 root root 8 may 11 2019 sbin -> usr/sbin drwxr-xr-x. 2 root root 6 may 11 2019 srv dr-xr-xr-x. 13 root root 0 aug 11 09:58 sys drwxrwxrwt. 7 root root 145 aug 9 21:40 tmp drwxr-xr-x. 12 root root 144 aug 9 21:40 usr drwxr-xr-x. 20 root root 262 aug 9 21:40 var
dockerfile中很多命令都十分相似，我们需要了解他的区别，最好的学习就是对比进行测试查看效果！
实战:tomcat镜像
1、准备镜像文件 tomcat压缩包 jdk压缩包
[root@localhost tomcat]# ls
apache-tomcat-8.5.43.tar.gz dockerfile jdk-8u211-linux-x64.tar.gz read.txt
2、编写dockerfile文件, 官方命名dockerfile，build会自动寻找这个文件，不需要 -f 指定！
# 引入基础 from centos # 作者信息 maintainer yinxiaodoong<m15010969094@163.com> # copy文件read.txt到容器的 /usr/local/read.txt 目录下 copy read.txt /usr/local/read.txt # 添加jdk tomcat ---> 自动解压 add jdk-8u211-linux-x64.tar.gz /usr/local/ add apache-tomcat-8.5.43.tar.gz /usr/local/ # 安装 vim 命令 run yum install -y vim # 配置 mypath env mypath /usr/local/ # 指定 进入容器默认路径 /user/local/ workdir $mypath # 配置jdk环境变量 env java_home /usr/local/jdk1.8.0_211 env classpath $java_home/lib/dt.jat:$java_home/lib/tools.jar # 配置tomcat环境变量 env catalina_home /usr/local/apache-tomcat-8.5.43 env catalina_bash /usr/local/apache-tomcat-8.5.43 env path $path:$java_home/bin:$catalina_home/lib:$catalina_home/bin # 暴露8080端口 expose 8080 # /usr/local/tomcat/webapps# # 启动容器时 启动tomcat cmd /usr/local/apache-tomcat-8.5.43/bin/startup.sh && tail -f /usr/local/apache-tomcat-8.5.43/logs/catalina.out # 构建tomcat镜像 [root@localhost tomcat]# docker build -t mytomcat [root@localhost tomcat]# docker images repository tag image id created size mytomcat latest a9707559afa1 8 seconds ago 693mb centos latest 0d120b6ccaa8 4 days ago 215mb [root@localhost tomcat]# docker run -d -p 8081:8080 --name mytomcat--01 -v /home/yinxiaodong/build/tomcat/test:/usr/local/apache-tomcat-8.5.43/webapps/test -v /home/yinxiaodong/build/tomcat/logs:/usr/local/apache-tomcat-8.5.43/logs mytomcat
发布自己的镜像
发布到 dockerhub
地址 注册自己的账号
确定自己的账号可以登录
在我们的服务器上提交
[root@localhost logs]# docker login --help usage: docker login [options] [server] log in to a docker registry. if no server is specified, the default is defined by the daemon. options: -p, --password string password --password-stdin take the password from stdin -u, --username string username [root@localhost logs]# [root@localhost logs]# docker login -u xxx -p xxx warning! using --password via the cli is insecure. use --password-stdin. 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
登录完毕后就可以提交镜像了
[root@localhost logs]# docker push xxx/mytomcat:1.0
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持移动技术网。
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