DockerFile

1.DockerFile简介

  Dockerfile是用来构建Docker镜像的构建文件，是由一系列命令和参数构成的脚本

  构建三步骤:编写Dockerfile文件->docker build->docker run

范例：DockerFile示例

https://github.com/CentOS/sig-cloud-instance-images/blob/f32666d2af356ed6835942ed753a4970e18bca94/docker/Dockerfile

2.DockerFile构建过程

 

总结 

3.DockerFile指令 

 

 

[1].实例1

  Docker Hub 中 99% 的镜像都是通过在 base 镜像中安装和配置需要的软件构建出来的

 

[2].实例2

  自定义mycentos目的使我们自己的镜像具备如下:登陆后的默认路径|vim编辑器| 查看网络配置ifconfig支持

 

(1).编写DockerFile

[root@pluto mydocker]# pwd

/mydocker

[root@pluto mydocker]# vim Dockerfile2

 

FROM centos:centos6.8

 

ENV MYPATH /usr/local

WORKDIR $MYPATH

 

RUN yum -y install vim

RUN yum -y install net-tools

 

EXPOSE 80

 

CMD echo $MYPATH

CMD echo "success--------------ok"

CMD /bin/bash

(2).构建build

语法：docker build -t 新镜像名字:TAG .

[root@pluto mydocker]# pwd

/mydocker

[root@pluto mydocker]# ll

总用量 8

-rw-r--r--. 1 root root 144 8月  18 15:48 Dockerfile

-rw-r--r--. 1 root root 197 8月  19 03:42 Dockerfile2

[root@pluto mydocker]# docker build -f /mydocker/Dockerfile2 -t centos:centos6.81 .

[root@pluto mydocker]# docker images

REPOSITORY          TAG                 IMAGE ID            CREATED              VIRTUAL SIZE

centos              centos6.81          c325fa072969        About a minute ago   380.9 MB

(3).运行

语法：docker run -it 新镜像名字:TAG

[root@6cea293ae495 local]# vim host

[root@6cea293ae495 local]# pwd

/usr/local

  添加vim编辑器成功，我们可以通过这种方式获得自己的工具库

(4).镜像历史

语法：docker history 镜像名

[root@pluto mydocker]# docker images centos

REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE

centos              centos6.81          c325fa072969        7 minutes ago       380.9 MB

 

[root@pluto mydocker]# docker history centos:centos6.81

IMAGE               CREATED             CREATED BY                                      SIZE                COMMENT

c325fa072969        7 minutes ago       /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "/bin/b   0 B                 

610a93db295c        7 minutes ago       /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "echo   0 B                 

c01a5a2195d7        7 minutes ago       /bin/sh -c #(nop) CMD ["/bin/sh" "-c" "echo $   0 B                 

adf973b1e485        7 minutes ago       /bin/sh -c #(nop) EXPOSE 80/tcp                 0 B                 

9598516913a1        7 minutes ago       /bin/sh -c yum -y install net-tools             23.32 MB            

3e60ce0af3d5        8 minutes ago       /bin/sh -c yum -y install vim                   163.1 MB            

583e9beff987        9 minutes ago       /bin/sh -c #(nop) WORKDIR /usr/local            0 B                 

db4a1be6d6dc        9 minutes ago       /bin/sh -c #(nop) ENV MYPATH=/usr/local         0 B                 

efa3cf7ee1f9        17 months ago       /bin/sh -c #(nop)  CMD ["/bin/bash"]            0 B                 

2e9485c70cb7        17 months ago       /bin/sh -c #(nop)  LABEL name=CentOS Base Ima   0 B                 

24cb4957fdbf        17 months ago       /bin/sh -c #(nop) ADD file:14c084af88ccd62ad7   194.5 MB            

3690474eb5b4        22 months ago       /bin/sh -c #(nop)  MAINTAINER The CentOS Proj   0 B                 

[3].实例3

 

(1).CMD

[root@pluto mydocker]# docker run -it -p 8888:8080 tomcat ls -l

[root@pluto mydocker]# docker ps

CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS               NAMES

  因为ls -l替换了CMD ["catalina.sh", "run"]，所以我们通过docker ps查看的时候tomcat并未启动起来

(2).ENTRYPOINT

  docker run 之后的参数会被当做参数传递给 ENTRYPOINT，之后形成新的命令组合.

①.CMD版IP查询

 

[root@pluto mydocker]# pwd

/mydocker

[root@pluto mydocker]# vim Dockerfile3

 

FROM centos:centos6.8

RUN yum install -y curl

CMD ["curl","-s","http://www.cip.cc"]

 

[root@pluto mydocker]# docker build -f /mydocker/Dockerfile3 -t centos:ip .

[root@pluto mydocker]# docker run -it centos:ip

 

②ENTRYPOINT版IP查询

 

  如果我们希望显示 HTTP 头信息，就需要加上 -i 参数,在CMD时会出现错误

[root@pluto mydocker]# docker run -it centos:ip -i

exec: "-i": executable file not found in $PATH

Error response from daemon: Cannot start container a436fb6d142dd601abdb44ced5ec0749df43c65db22f770a50f7519814574380: [8] System error: exec: "-i": executable file not found in $PATH

 

[root@pluto mydocker]# pwd

/mydocker

[root@pluto mydocker]# vim Dockerfile4

 

FROM centos:centos6.8

RUN yum install -y curl

ENTRYPOINT ["curl","-s","http://cip.cc"]

 

[root@pluto mydocker]# docker build -f /mydocker/Dockerfile4 -t centos:ip1 .

 

[4].实例4

 

(1).FROM

[root@pluto mydocker]# vim Dockerfile5

 

FROM centos:centos6.8

RUN yum install -y curl

ENTRYPOINT ["curl","-s","http://cip.cc"]

ONBUILD RUN echo "father images onbuild ----"

 

[root@pluto mydocker]# docker build -f /mydocker/Dockerfile5 -t centos:myip_father .

[root@pluto mydocker]# docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE

centos              myip_father         747a0f27ad7e        46 seconds ago      300.6 MB

 

[root@pluto mydocker]# vim Dockerfile6

FROM centos:myip_father

RUN yum install -y curl

ENTRYPOINT ["curl","-s","http://cip.cc"]

ONBUILD RUN echo "father images onbuild ----"

 

[root@pluto mydocker]# docker build -f /mydocker/Dockerfile6 -t centos:father_son .

(2).自定义Tomcat

①Dockerfile

[root@pluto /]# mkdir -p /pluto/mydockerfile/tomcat2020

[root@pluto tomcat2020]# pwd

/pluto/mydockerfile/tomcat2020

[root@pluto tomcat2020]# touch c.txt

[root@pluto tomcat2020]# cp /opt/apache-tomcat-7.0.70.tar.gz .

[root@pluto tomcat2020]# cp /opt/jdk-7u79-linux-x64.gz .

[root@pluto tomcat2020]# ls

apache-tomcat-7.0.70.tar.gz  c.txt  jdk-7u79-linux-x64.gz

[root@pluto tomcat2020]# vim Dockerfile

 

FROM centos:centos6.8

MAINTAINER    pluto<pluto@163.com>

#把宿主机当前上下文的c.txt拷贝到容器/usr/local/路径下

COPY c.txt /usr/local/cincontainer.txt

#把java与tomcat添加到容器中

ADD jdk-7u79-linux-x64.gz /usr/local/

ADD apache-tomcat-7.0.70.tar.gz /usr/local/

#安装vim编辑器

RUN yum -y install vim

#设置工作访问时候的WORKDIR路径，登录落脚点

ENV MYPATH /usr/local

WORKDIR $MYPATH

#配置java与tomcat环境变量

ENV JAVA_HOME /usr/local/jdk1.7.0_79

ENV CLASSPATH $JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

ENV CATALINA_HOME /usr/local/apache-tomcat-7.0.70

ENV CATALINA_BASE /usr/local/apache-tomcat-7.0.70

ENV PATH $PATH:$JAVA_HOME/bin:$CATALINA_HOME/lib:$CATALINA_HOME/bin

#容器运行时监听的端口

EXPOSE  8080

#启动时运行tomcat

# ENTRYPOINT ["/usr/local/apache-tomcat-7.0.70/bin/startup.sh" ]

# CMD ["/usr/local/apache-tomcat-7.0.70/bin/catalina.sh","run"]

CMD /usr/local/apache-tomcat-7.0.70/bin/startup.sh && tail -F /usr/local/apache-tomcat-7.0.70/bin/logs/catalina.out

  注：上面的apache-tomcat-7.0.70和jdk1.7.0_79需要注意，自己的版本需要对应，最简单获得的方法就是解压后就可以知道这两个是怎么填写。如

[root@pluto apache-tomcat-7.0.70]# pwd

/opt/apache-tomcat-7.0.70

[root@pluto jdk1.7.0_79]# pwd

/opt/jdk1.7.0_79

就可以将这两个参数填写到上面中黑体字部分

②构建

[root@pluto tomcat2020]# docker build -f /pluto/mydockerfile/tomcat2020/Dockerfile  -t centos:tomcat .

 

③运行

[root@pluto tomcat2020]# docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE

centos              tomcat              9fe67481da23        2 minutes ago       677.5 MB

 

[root@pluto tomcat2020]# docker run -d -p 9080:8080 --name mytomcat -v /pluto/mydockerfile/tomcat7/test:/usr/local/apache-tomcat-7.0.70/webapps/test -v /pluto/mydockerfile/tomcat7/tomcat7logs/:/usr/local/apache-tomcat-7.0.70/logs --privileged=true centos:tomcat

8cb50f97b47735e0c10189993670d324a12b16a007f50caba2e9576b14a90fa0

 

[root@pluto tomcat2020]# docker ps

CONTAINER ID        IMAGE               COMMAND                CREATED             STATUS              PORTS                    NAMES

8cb50f97b477        centos:tomcat       "/bin/sh -c '/usr/lo   17 seconds ago      Up 17 seconds       0.0.0.0:9080->8080/tcp   mytomcat

 

[root@pluto tomcat2020]# docker exec 8cb50f97b477 ls -l

 

注：若访问失败可能是防火墙的原因，关闭防火墙或者添加规则即可

若出现"Error response from daemon: Conflict. The name "mytomcat" is already in use by container 676291e51f29. You have to delete (or rename) that container to be able to reuse that name."则可以通过以下方法解决

https://blog.csdn.net/qq_37189082/article/details/100051374

④发布web服务

[root@pluto test]# mkdir WEB-INF

[root@pluto test]# cd WEB-INF/

[root@pluto WEB-INF]# pwd

/pluto/mydockerfile/tomcat2020/test/WEB-INF

[root@pluto WEB-INF]# vim web.xml

 

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xmlns="http://java.sun.com/xml/ns/javaee"

  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

  id="WebApp_ID" version="2.5">

  

  <display-name>test</display-name>

 

</web-app>

 

[root@pluto test]# cd ..

[root@pluto test]# vim a.jsp

 

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<html>

  <head>

    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

    <title>Insert title here</title>

  </head>

  <body>

    -----------welcome------------

    <%="i am in docker tomcat self "%>

    <br>

    <br>

    <% System.out.println("=============docker tomcat self");%>

  </body>

</html>

 

[root@pluto test]# docker restart mytomcat

 

⑤查看日志

[root@pluto tomcat7logs]# pwd

[root@pluto tomcat7logs]# ll

[root@pluto tomcat7logs]# tail -n 5 catalina.out

  网页刷新几次就会出现几次"docker tomcat self"

 

4.总结