一、dockfile 说明
docker 运行一个自定义的image时，就需要自己来定义，这时候就需要dockfile了。
二、docker commit生成新镜像
2.1.运行容器
# docker run -it centos /bin/bash
2.2.安装vim
# yum install vim
2.3.将容器打包成新镜像
# docker commit 07929e3af3ef cent-vim
2.4.查看新镜像
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
cent-vim latest 4659d1ec001d 7 seconds ago 225MB
centos latest 1e1148e4cc2c 8 days ago 202MB
nginx latest 568c4670fa80 2 weeks ago 109MB
ubuntu latest 93fd78260bd1 3 weeks ago 86.2MB
busybox latest 59788edf1f3e 2 months ago 1.15MB
这样操作，非常不便，切容易出错，如何有更好方式来定义镜像呢？这就需要dockfile了
三、dockfile
3.1.编辑dockfile文件
# vim Dockerfile FROM centos RUN yum update && yum install vim -y
3.2.build构建镜像
# docker build -t centos-vim . #-t 将新镜像命名为centos-vim
Sending build context to Docker daemon 16.9kB
Step 1/2 : FROM centos #镜像来源
---> 1e1148e4cc2c
Step 2/2 : RUN yum update && yum install vim -y #构建时执行的命令
---> Running in d7a98cfdffb7
Loaded plugins: fastestmirror, ovl
Determining fastest mirrors
* base: centos.ustc.edu.cn
* extras: mirrors.aliyun.com
* updates: mirrors.cn99.com
No packages marked for update
Loaded plugins: fastestmirror, ovl
Loading mirror speeds from cached hostfile
* base: centos.ustc.edu.cn
* extras: mirrors.aliyun.com
* updates: mirrors.cn99.com
Resolving Dependencies
--> Running transaction check
---> Package vim-enhanced.x86_64 2:7.4.160-5.el7 will be installed
....
Removing intermediate container d7a98cfdffb7
---> 82fd472e3387
Successfully built 82fd472e3387 #构建成功，镜像ID为82fd472e3387
Successfully tagged centos-vim:latest #为镜像添加一个TAG
查看镜像：
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos-vim latest 82fd472e3387 2 minutes ago 327MB
cent-vim latest 4659d1ec001d About an hour ago 225MB
centos latest 1e1148e4cc2c 8 days ago 202MB
nginx latest 568c4670fa80 2 weeks ago 109MB
ubuntu latest 93fd78260bd1 3 weeks ago 86.2MB
busybox latest 59788edf1f3e 2 months ago 1.15MB
3.3.构建镜像时拷贝文件
3.3.1.文件内容：
# cat ckl.txt The narcissus bloom every year.
3.3.2.dockfile 内容
# vim Dockerfile FROM centos RUN yum update && yum install vim -y COPY ckl.txt /
3.3.3.构建镜像
# docker build -t cent-ckl-vim .
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
cent-ckl-vim latest fc090867ce91 42 seconds ago 327MB
centos-vim latest 82fd472e3387 16 minutes ago 327MB
cent-vim latest 4659d1ec001d About an hour ago 225MB
centos latest 1e1148e4cc2c 8 days ago 202MB
nginx latest 568c4670fa80 2 weeks ago 109MB
ubuntu latest 93fd78260bd1 3 weeks ago 86.2MB
busybox latest 59788edf1f3e 2 months ago 1.15MB
3.3.4.运行容器查看内容
# docker run -it cent-ckl-vim
[root@050821c80ca8 /]#
[root@050821c80ca8 /]#
[root@050821c80ca8 /]# ls
anaconda-post.log bin ckl.txt dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
[root@050821c80ca8 /]#
[root@050821c80ca8 /]#
[root@050821c80ca8 /]# cat ckl.txt
The narcissus bloom every year. #拷贝的文件
[root@050821c80ca8 /]#
[root@050821c80ca8 /]#
[root@050821c80ca8 /]# vim 1.txt #vim 已经按照
3.3.5.拷贝容器的另一种方式
# vim Dockerfile FROM centos RUN yum update && yum install vim -y ADD nginx-1.12.2.tar.gz /
构建镜像：
# docker build -t centos-ckl-ng .
Sending build context to Docker daemon 1MB
Step 1/3 : FROM centos
---> 1e1148e4cc2c
Step 2/3 : RUN yum update && yum install vim -y
---> Using cache #之前已经构建过了以上步骤，所以这里使用了缓存
---> 82fd472e3387
Step 3/3 : ADD nginx-1.12.2.tar.gz /
---> 248da05fb49e
Successfully built 248da05fb49e
Successfully tagged centos-ckl-ng:latest
查看镜像：
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos-ckl-ng latest 248da05fb49e 23 seconds ago 333MB
centos-vim latest 82fd472e3387 24 minutes ago 327MB
cent-vim latest 4659d1ec001d About an hour ago 225MB
centos latest 1e1148e4cc2c 8 days ago 202MB
nginx latest 568c4670fa80 2 weeks ago 109MB
ubuntu latest 93fd78260bd1 3 weeks ago 86.2MB
busybox latest 59788edf1f3e 2 months ago 1.15MB
运行镜像容器：
# docker run -it centos-ckl-ng
[root@a7bdc5e9ecf4 /]#
[root@a7bdc5e9ecf4 /]#
[root@a7bdc5e9ecf4 /]# ls
anaconda-post.log bin dev etc home lib lib64 media mnt nginx-1.12.2 opt proc root run sbin srv sys tmp usr var
#tar 包已经被解压，COPY则不会
3.3.6.构建镜像启动后运行命令CMD
编辑文件：
# vim Dockerfile
RUN yum install -y httpd
RUN yum install -y httpd
FROM centos
RUN yum update && yum install vim -y
ADD nginx-1.12.2.tar.gz /
RUN yum install -y httpd && yum -y install initscripts pm-utils
CMD ["service","httpd","start"]
构建镜像：
# docker build -t cent-ckl-http .
查看镜像：
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
cent-ckl-http latest d848cf5482e6 4 seconds ago 443MB
centos-ckl-ng latest 248da05fb49e 22 minutes ago 333MB
centos-vim latest 82fd472e3387 About an hour ago 327MB
cent-vim latest 4659d1ec001d 2 hours ago 225MB
centos latest 1e1148e4cc2c 8 days ago 202MB
nginx latest 568c4670fa80 2 weeks ago 109MB
ubuntu latest 93fd78260bd1 3 weeks ago 86.2MB
busybox latest 59788edf1f3e 2 months ago 1.15MB
运行镜像的容器：
# docker run -it cent-ckl-http
Redirecting to /bin/systemctl start httpd.service #已经执行了CMD的命令
Failed to get D-Bus connection: Operation not permitted
这个的原因是因为dbus-daemon没能启动。其实systemctl并不是不可以使用。将你的CMD或者entrypoint设置为/usr/sbin/init即可。会自动将dbus等服务启动起来。
然后就可以使用systemctl了。
# docker run -it --privileged cent-ckl-http init
[FAILED] Failed to start LSB: Bring up/down networking.
See 'systemctl status network.service' for details.
没有搞定！！！
3.3.7.构建镜像设置环境变量及目录
修改dockfile文件
# vim Dockerfile
FROM centos
RUN yum update && yum install vim -y && mkdir /tmp/soft
ADD nginx-1.12.2.tar.gz /tmp/soft
WORKDIR /tmp/soft/nginx-1.12.2
ENV NAME=ckl
RUN yum install -y httpd && yum -y install initscripts pm-utils
CMD ["service","httpd","start"]
CMD ["echo","$NAME"]
构建镜像文件：
# docker build -t cent-ckl-http .
启动镜像容器：
# docker run -it cent-ckl-http /bin/bash
[root@355cc5d1501e nginx-1.12.2]# #当前目录
[root@355cc5d1501e nginx-1.12.2]#
[root@355cc5d1501e nginx-1.12.2]# echo $NAME #变量
ckl
三、dockfile 参数说明
Dockerfile 一般分为四部分：基础镜像信息、维护者信息、镜像操作指令和容器启动时执行指令 FROM：指定基础镜像，必须为第一个命令 MAINTAINER: 维护者信息 RUN：构建镜像时执行的命令 ADD：将本地文件添加到容器中，tar类型文件会自动解压，可以访问网络资源，类似wget COPY：功能类似ADD，但是是不会自动解压文件，也不能访问网络资源 CMD：构建容器后调用，也就是在容器启动时才进行调用。 ENTRYPOINT：配置容器，使其可执行化。配合CMD可省去"application"，只使用参数。 LABEL：用于为镜像添加元数据 ENV：设置环境变量 EXPOSE：指定于外界交互的端口 VOLUME：用于指定持久化目录 WORKDIR：工作目录，类似于cd命令 USER:指定运行容器时的用户名或 UID，后续的 RUN 也会使用指定用户。使用USER指定用户时，可以使用用户名、UID或GID，或是两者的组合。当服务不需要管理员权限时，可以通过该命令指定运行用户。并且可以在之前创建所需要的用户 ARG：用于指定传递给构建运行时的变量 ONBUILD：用于设置镜像触发器
四、配置nginx安装示例
4.1.编辑dockfile文件
vim Dockerfile
FROM centos
MAINTAINER ckl
RUN yum update && yum -y install vim zlib zlib-devel openssl openssl-devel gcc-c++ pcre pcre-devel initscripts pm-utils
RUN mkdir /tmp/soft
RUN adduser ckl
ADD nginx-1.12.2.tar.gz /tmp/soft
WORKDIR /tmp/soft/nginx-1.12.2
RUN ./configure --prefix=/usr/local/nginx --user=ckl --group=ckl --with-http_ssl_module && make && make install
ENV PATH /usr/local/nginx/sbin:$PATH
EXPOSE 80
CMD ["/usr/local/nginx/sbin/nginx","-g","daemon off;"]
4.2.构建镜像
docker build -t nginx-centos .
4.3.启动镜像容器：
docker run -p 80 --name 'ckl-ng' -d nginx-centos
4.4.已经启动了nginx
# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
4f68eeb38e28 nginx-centos "/usr/local/nginx/sb…" 7 minutes ago Up 7 minutes 0.0.0.0:32768->80/tcp ckl-ng
4.5.访问：
# curl http://172.17.0.3
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
转载于:https://blog.51cto.com/ckl893/2331369
