dockerfile
dockerfile介绍
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构建成为一个镜像
- docker run运行镜像
- docker push发布镜像(dockerhub、阿里云仓库)
查看官方是怎么做的
FROM scratch ADD centos-8-x86_64.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="20201204" CMD ["/bin/bash"]
很多官方镜像都是基础包,很多功能没有,我们通常会自己搭建自己的镜像
dockerfile构建过程
基础知识:
- 每个保留关键字(指令)必须是大写字母
- 执行从上到下顺序执行
- #表示注释
- 每一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,必须掌握
步骤:开发、部署、运维
dockerfile:构建文件,定义了一切的步骤,源代码
dockerimage:通过dockerfile构建生成的镜像,最终发布和运行的产品,原来是jar,war
docker容器:容器就是镜像运行起来提供服务的
dockerfile指令
指令 | 描述 |
FROM | 基础镜像,一切从这里开始构建 |
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 | 添加内容 |
WORKDIR | 镜像工作目录 |
VOLUME | 挂载的目录 |
EXPOSE | 暴露的端口 |
RUN |
程序运行之后要干的事 |
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dockerfile 这个时候就会运行ONBUILD的指令,触发指令 |
COPY |
类似ADD命令,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
创建一个自己的centos
在home目录下创建dockerfile
[root@iZmu0fa4hv0jwzZ home]# mkdir dockerfile
[root@iZmu0fa4hv0jwzZ home]# cd dockerfile/
编写自己的dockerfile文件
[root@iZmu0fa4hv0jwzZ dockerfile]# vim mydockerfile-centos [root@iZmu0fa4hv0jwzZ dockerfile]# cat mydockerfile-centos FROM centos MAINTAINER ayanami<12121212@qq.com> ENV MYPATH /usr/local WORKDIR $MYPATH RUN yum -y install vim RUN yum -y install net-tools EXPOSE 80 CMD echo $MYPATH CMD echo "---end---" CMD /bin/bash
运行dockerfile文件
命令 docker build -f dockerfile文件路径 -t 镜像名:[tag]
[root@iZmu0fa4hv0jwzZ dockerfile]# docker build -f mydockerfile-centos -t mycentos:0.1 .
查看镜像
[root@iZmu0fa4hv0jwzZ dockerfile]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE mycentos 0.1 f1661e656e39 3 minutes ago 295MB
测试运行
[root@iZmu0fa4hv0jwzZ dockerfile]# docker run -it mycentos:0.1 [root@dd4a17c47af7 local]# pwd /usr/local [root@iZmu0fa4hv0jwzZ dockerfile]# docker run -it mycentos:0.1 [root@dd4a17c47af7 local]# pwd /usr/local [root@dd4a17c47af7 local]# ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
列出本地镜像的变更历史
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 [root@iZmu0fa4hv0jwzZ dockerfile]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE mycentos 0.1 f1661e656e39 12 minutes ago 295MB test/centos 1.0 11bfc295e9b3 8 hours ago 209MB tomcat02 1.0 c93f6d59c630 23 hours ago 672MB tomcat 9.0 5505f7218e4d 4 days ago 667MB nginx latest d1a364dc548d 3 weeks ago 133MB mysql 5.7 2c9028880e58 5 weeks ago 447MB centos latest 300e315adb2f 6 months ago 209MB [root@iZmu0fa4hv0jwzZ dockerfile]# docker history f1661e656e39 IMAGE CREATED CREATED BY SIZE COMMENT f1661e656e39 12 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "/bin… 0B bd1b8aa98ba2 12 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "echo… 0B 361c7948f003 12 minutes ago /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "echo… 0B 54ebf51ed5ed 12 minutes ago /bin/sh -c #(nop) EXPOSE 80 0B 45dfc9afcbe3 12 minutes ago /bin/sh -c yum -y install net-tools 24.9MB 4f1c0c7e132a 12 minutes ago /bin/sh -c yum -y install vim 60.7MB 44e99b19d8fa 13 minutes ago /bin/sh -c #(nop) WORKDIR /usr/local 0B a137866c37b0 13 minutes ago /bin/sh -c #(nop) ENV MYPATH=/usr/local 0B fb306da081ac 13 minutes ago /bin/sh -c #(nop) MAINTAINER ayanami<121212… 0B 300e315adb2f 6 months ago /bin/sh -c #(nop) CMD ["/bin/bash"] 0B <missing> 6 months ago /bin/sh -c #(nop) LABEL org.label-schema.sc… 0B <missing> 6 months ago /bin/sh -c #(nop) ADD file:bd7a2aed6ede423b7… 209MB
CMD和ENTRYPOINT的区别
测试CMD
在dockerfile目录下新建dockerfile文件
[root@iZmu0fa4hv0jwzZ dockerfile]# vim dockerfile-cmd-test [root@iZmu0fa4hv0jwzZ dockerfile]# cat dockerfile-cmd-test FROM centos CMD ["ls","-a"]
通过dockerfile文件创建镜像
[root@iZmu0fa4hv0jwzZ dockerfile]# docker build -f dockerfile-cmd-test -t cmdtest . Sending build context to Docker daemon 3.072kB Step 1/2 : FROM centos ---> 300e315adb2f Step 2/2 : CMD ["ls","-a"] ---> Running in 15ab54a9f711 Removing intermediate container 15ab54a9f711 ---> 3f66dbcdb279 Successfully built 3f66dbcdb279 Successfully tagged cmdtest:latest
运行
[root@iZmu0fa4hv0jwzZ dockerfile]# docker run 3f66dbcdb279 . .. .dockerenv bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
发现 ls -a 命令生效
如果追加一个 -l命令
[root@iZmu0fa4hv0jwzZ dockerfile]# docker run 3f66dbcdb279 -l docker: Error response from daemon: OCI runtime create failed: container_linux.go:380: starting container process caused: exec: "-l": executable file not found in $PATH: unknown.
会报错,这是因为cmd的情况下 -l 替换了 CMD["ls","-a"] 命令,-l 不是命令所以报错
测试ENTRYPOINT
新建dockerfile文件
[root@iZmu0fa4hv0jwzZ dockerfile]# cat dockerfile-cmd-entrypoint FROM centos ENTRYPOINT ["ls","-a"]
通过dockerfile文件创建镜像
[root@iZmu0fa4hv0jwzZ dockerfile]# docker build -f dockerfile-cmd-entrypoint -t entrypoint-test . Sending build context to Docker daemon 4.096kB Step 1/2 : FROM centos ---> 300e315adb2f Step 2/2 : ENTRYPOINT ["ls","-a"] ---> Running in 6bf9a88469cf Removing intermediate container 6bf9a88469cf ---> 0c2a88ea9329 Successfully built 0c2a88ea9329 Successfully tagged entrypoint-test:latest
运行
[root@iZmu0fa4hv0jwzZ dockerfile]# docker run 0c2a88ea9329 . .. .dockerenv bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
追加一个 -l 命令
[root@iZmu0fa4hv0jwzZ dockerfile]# docker run 0c2a88ea9329 -l total 0 drwxr-xr-x 1 root root 6 Jun 22 03:33 . drwxr-xr-x 1 root root 6 Jun 22 03:33 .. -rwxr-xr-x 1 root root 0 Jun 22 03:33 .dockerenv lrwxrwxrwx 1 root root 7 Nov 3 2020 bin -> usr/bin drwxr-xr-x 5 root root 340 Jun 22 03:33 dev drwxr-xr-x 1 root root 66 Jun 22 03:33 etc drwxr-xr-x 2 root root 6 Nov 3 2020 home lrwxrwxrwx 1 root root 7 Nov 3 2020 lib -> usr/lib lrwxrwxrwx 1 root root 9 Nov 3 2020 lib64 -> usr/lib64 drwx------ 2 root root 6 Dec 4 2020 lost+found drwxr-xr-x 2 root root 6 Nov 3 2020 media drwxr-xr-x 2 root root 6 Nov 3 2020 mnt drwxr-xr-x 2 root root 6 Nov 3 2020 opt dr-xr-xr-x 115 root root 0 Jun 22 03:33 proc dr-xr-x--- 2 root root 162 Dec 4 2020 root drwxr-xr-x 11 root root 163 Dec 4 2020 run lrwxrwxrwx 1 root root 8 Nov 3 2020 sbin -> usr/sbin drwxr-xr-x 2 root root 6 Nov 3 2020 srv dr-xr-xr-x 13 root root 0 Jun 22 03:33 sys drwxrwxrwt 7 root root 145 Dec 4 2020 tmp drwxr-xr-x 12 root root 144 Dec 4 2020 usr drwxr-xr-x 20 root root 262 Dec 4 2020 var
说明ENTRYPOINT的追加命令是直接拼接在ENTRYPOINT命令的后面
使用dockerfile创建tomcat镜像
准备镜像文件、tomcat压缩包、jdk压缩包
[root@iZmu0fa4hv0jwzZ mysoftware]# ll total 152764 -rw-r--r-- 1 root root 11489338 Jun 22 12:20 apache-tomcat-9.0.48.tar.gz -rw-r--r-- 1 root root 144935989 Jun 22 12:21 jdk-8u291-linux-x64.tar.gz
[root@iZmu0fa4hv0jwzZ mysoftware]# touch readme.txt
编写dockerfile文件
官方命名 Dockerfile,build会自动寻找这个文件,就不需要 -f 指定了
[root@iZmu0fa4hv0jwzZ mysoftware]# vim Dockerfile [root@iZmu0fa4hv0jwzZ mysoftware]# cat Dockerfile FROM centos MAINTAINER ayanami<ayanamiblhx@git.com> COPY readme.txt /usr/local/readme.txt ADD jdk-8u291-linux-x64.tar.gz /usr/local/ ADD apache-tomcat-9.0.48.tar.gz /usr/local/ RUN yum -y install vim ENV MYPATH /usr/local WORKDIR $MYPATH ENV JAVA_HOME /usr/local/jdk1.8 ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar ENV CATALINA_HOME /usr/local/apache-tomcat-9.0.48 ENV CATALINA_BASH /usr/local/apache-tomcat-9.0.48 ENV PATH $PATH:$JAVA_HOME/bin:$CATALINA_HOME/lib:$CATALINA_HOME/bin EXPOSE 8080 CMD /usr/local/apache-tomcat-9.0.48/bin/startup.sh && tail -F /usr/local/apache-tomcat-9.0.48/bin/logs/catalina.out
构建镜像
[root@iZmu0fa4hv0jwzZ mysoftware]# docker build -t diytomcat .
查看镜像
[root@iZmu0fa4hv0jwzZ mysoftware]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
diytomcat latest bcfda04673f9 About a minute ago 646MB
运行镜像并指定挂载目录
[root@iZmu0fa4hv0jwzZ mysoftware]# docker run -d -p 9090:8080 --name mytomcat02 -v /home/dockerfile/mysoftware/test:/usr/local/apache-tomcat-9.0.48/webapps/test -v /home/dockerfile/mysoftware/tomcatlogs:/usr/local/apache-tomcat-9.0.48/logs diytomcat
进入容器
[root@iZmu0fa4hv0jwzZ mysoftware]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES edeba1aa9068 diytomcat "/bin/sh -c '/usr/lo…" About a minute ago Up About a minute 0.0.0.0:9090->8080/tcp, :::9090->8080/tcp mytomcat02 [root@iZmu0fa4hv0jwzZ mysoftware]# docker exec -it edeba1aa9068 /bin/bash
[root@edeba1aa9068 local]# ls apache-tomcat-9.0.48 bin etc games include jdk1.8.0_291 lib lib64 libexec readme.txt sbin share src
[root@edeba1aa9068 local]# cd apache-tomcat-9.0.48/
[root@edeba1aa9068 apache-tomcat-9.0.48]# ls BUILDING.txt CONTRIBUTING.md LICENSE NOTICE README.md RELEASE-NOTES RUNNING.txt bin conf lib logs temp webapps work
进入主机测试tomcat
[root@iZmu0fa4hv0jwzZ mysoftware]# curl localhost:9090 <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <title>Apache Tomcat/9.0.48</title> <link href="favicon.ico" rel="icon" type="image/x-icon" /> <link href="tomcat.css" rel="stylesheet" type="text/css" />
表明配置成功
使用tomcat部署项目
进入主机test目录
[root@iZmu0fa4hv0jwzZ mysoftware]# cd test
创建WEB-INF目录
[root@iZmu0fa4hv0jwzZ test]# mkdir WEB-INF [root@iZmu0fa4hv0jwzZ test]# cd WEB-INF/ [root@iZmu0fa4hv0jwzZ WEB-INF]# vim web.xml <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> </web-app> [root@iZmu0fa4hv0jwzZ WEB-INF]# cd .. [root@iZmu0fa4hv0jwzZ test]# vim index.jsp <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> $END$ </body> </html>
在浏览器上访问tomcat
发现可以访问,说明项目部署成功
发布镜像到dockerhub
在dockerhub注册自己的账号
地址:Docker Hub
在服务器上提交自己的镜像
登录
[root@iZmu0fa4hv0jwzZ mysoftware]# docker login -u 你的用户名 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
更改镜像名
docker tag 镜像id 用户名/镜像名:[tag] [root@iZmu0fa4hv0jwzZ mysoftware]# docker tag 8e3c4b61a897 ayanamiblhx/diytomcat:1.0
提交自己的镜像
[root@iZmu0fa4hv0jwzZ mysoftware]# docker push ayanamiblhx/diytomcat:1.0 The push refers to repository [docker.io/ayanamiblhx/diytomcat] 838d54b051df: Pushed 98f252f744ee: Pushed d75d09d37a7e: Pushed e147dbc79e6e: Pushed