table of Contents
.Docker a mirror made of three ways
Based on the existing image creation (docker commit)
Create a template-based local mirroring
Detailed instructions two .Dockerfile
.Docker a mirror made of three ways
Based on the existing image creation (docker commit)
- View existing images
[root@cloud ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest 6678c7c2e56c 2 weeks ago 127MB
httpd latest c5a012f9cf45 3 weeks ago 165MB
centos latest 470671670cac 2 months ago 237MB
[root@cloud ~]#
-
Create a container and run
[root@cloud ~]# docker create -it centos /bin/bash
7e750101b0eef5720205f6b4816d23f66815bb0bda5bc4f38935ad0fe03f80aa
[root@cloud ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7e750101b0ee centos "/bin/bash" 14 seconds ago Created hopeful_dirac
[root@cloud ~]# docker start 7e750101b0ee
7e750101b0ee
[root@cloud ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7e750101b0ee centos "/bin/bash" 40 seconds ago Up 13 seconds hopeful_dirac
[root@cloud ~]# - Create a mirror on the container
//-m指定该镜像的信息
//-a指定制作该镜像的作者
//centos:new 为镜像名和标签名
[root@cloud ~]# docker commit -m "new images" -a "androot" 7e750101b0ee centos:new
sha256:94b86b016dc0313e8e6d628d960e0910d130243674d585419b611a2c3e47920d
//查看新生成的镜像
[root@cloud ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
centos new 94b86b016dc0 5 seconds ago 237MB
nginx latest 6678c7c2e56c 2 weeks ago 127MB
httpd latest c5a012f9cf45 3 weeks ago 165MB
centos latest 470671670cac 2 months ago 237MB
[root@cloud ~]#
Create a template-based local mirroring
- The Internet to download a module, downloaded the debian module
wget http://download.openvz.org/template/precreated/debian-7.0-x86-minimal.tar.gz
-
Create a mirror
[root@cloud ~]# ls
debian-7.0-x86-minimal.tar.gz mysql
[root@cloud ~]# cat debian-7.0-x86-minimal.tar.gz | docker import - debian:local
sha256:72fa7440a81c379c884c4e43638a0bac3eef47c4f455a7f6746da4852abaa836
[root@cloud ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
debian local 72fa7440a81c 2 minutes ago 215MB
centos new 94b86b016dc0 9 minutes ago 237MB
nginx latest 6678c7c2e56c 2 weeks ago 127MB
httpd latest c5a012f9cf45 3 weeks ago 165MB
centos latest 470671670cac 2 months ago 237MB
[root@cloud ~]#
docker import: create a mirror from the archive
Usage is as follows:
docker import [OPTIONS] file | URL | - REPOSITORY[:TAG]
OPENTIONS Description:
-c: Application docker command to create a mirror
-m: caption when submitted
Custom image based Dockerfile
- Create a file in the local Dockerfile
[root@cloud ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
debian local 72fa7440a81c 21 minutes ago 215MB
centos new 94b86b016dc0 28 minutes ago 237MB
nginx latest 6678c7c2e56c 2 weeks ago 127MB
httpd latest c5a012f9cf45 3 weeks ago 165MB
centos latest 470671670cac 2 months ago 237MB
[root@cloud ~]#
- Creating execute scripts, and web interface
[root@cloud docker]# pwd
/docker
[root@cloud docker]# vi run.sh
[root@cloud docker]# cat run.sh
#!/bin/bash
rm -rf /run/httpd/*
exec /usr/sbin/apachectl -D FOREGROUND
[root@cloud docker]# echo "this is web test" > index.html
[root@cloud docker]# ls
Dockerfile index.html run.sh
[root@cloud docker]#
- Generate Mirror
[root@cloud docker]# docker build -t new_httpd:centos .
。。。。。。
Successfully built bbbb46a6633e
Successfully tagged new_httpd:centos
[root@cloud docker]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
new_httpd centos bbbb46a6633e 46 seconds ago 414MB
debian local 72fa7440a81c 31 minutes ago 215MB
centos new 94b86b016dc0 38 minutes ago 237MB
nginx latest 6678c7c2e56c 2 weeks ago 127MB
httpd latest c5a012f9cf45 3 weeks ago 165MB
centos latest 470671670cac 2 months ago 237MB
[root@cloud docker]#
- The use of image creation and operation of the vessel
[root@cloud docker]# docker run -d -p 1216:80 new_httpd:centos
3147e2b184ada8128d4ed4dad219c139d2da84bca7036560168b0ad289d1fbb6
[root@cloud docker]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3147e2b184ad new_httpd:centos "/run.sh" 6 seconds ago Up 5 seconds 0.0.0.0:1216->80/tcp lucid_blackwell
[root@cloud docker]# -p port specify the mapping, network traffic will next docker detailed explanation
- Test container, http: //123.57.242.90: 1216
Detailed instructions two .Dockerfile
Dockerfile concept
- Dockerfile is used to build docker mirrored build file, is a series of commands and parameters, similar to shell scripts
- Dockerfile raw materials software and docker mirror is software deliverables.
- Docker containers can be considered software running state
- Each instruction Dockerfile reserved words must be followed by capital letters and a parameter
- Dockerfile of each instruction will create a new image layer, and mirror commit
FROM
- 用法：FROM <image>
- FROM construct basis for specifying the source of the images in the image, if not specified local mirror, the mirror will automatically pull down from the public repository Docker
- FROM must be the first line of the comment instruction Dockerfile Africa, the first instruction that is Dockerfile must start FROM
- If there is a demand must create multiple mirrors in a Dockerfile, the FROM can appear multiple times
- If RFOM statement does not specify the mirror tag, the default label use latest
MAINTAINER
- 用法：MAINTAINER <name>
- Create a user to specify the mirror
RUN
- RUN action command is to be executed on the basis of the current image as a new image and submit mirror after RUN submitted before the subsequent RUN are based. Mirroring is layered, can be submitted by any of the points to create a historical image, similar to the source code version control
- RUN command implemented in two ways
The first
- RUN "scripting", "parameter 1" and "parameter 2"
The second
- RUN ["sh","-c","echo","$HOME"]
Note: The next time you build the cache when RUN is generated does not fail, it will be reused, can be used docker build --no-cache command
CMD
- CMD command specifies Dockerfile used only once in the file, if there multiple times, only the last one will work
- CMD purpose is to provide a default command option when you start the container. Specifies the command to run if the user starts the container, CMD command instruction will overwrite
- CMD is used in three ways
1.CMD "执行文件","参数1","参数2"
2.CMD "参数1","参数2"
3.CMD command 参数1 参数2(shell from)Note: CMD will perform at startup container, build is not executed, and RUN only perform when building a mirrored, after a subsequent image build is complete, the vessel will start regardless of the RUN
EXPOSE
- EXPOSE command is designated port mapping Docker container outside, you need to run in the docker -p / -P take effect
- EXPOSE usage: EXPOSE <port> [<port> ...]
ENV
- ENV command to specify an environment variable, will be used in subsequent instruction RUN, and remain in the container runtime
- ENV usage
1.ENV <key> <value> #只能设置一个变量
2.ENV <key>=<value> #允许一次设置多个变量- Examples are as follows
##例子
ENV myName="John Doe" myDog=rex\the\dog \
myCat=fluffy
##等同于
ENV myName John Doe
ENV myDog Rex The Dog
ENV myCat fluffy
ADD
- ADD Copy local host file, directory, or from a remote file URLS added to the container and the specified path
- GO supported by regular fuzzy matching, specific rules can be found in Go filepath.Match
- Road King Road King must be absolute, if not present, will automatically create the corresponding directory
- Road King must be a relative path where the path Dockerfile
- If it is a directory, only the contents of the directory replication, and the directory itself will not be copied
- ADD usage: ADD <src> ... <test>
COPY
- COPY copy files or directories, and added to the container specified path. Use with ADD, the only difference is that you can not specify a remote file URLS
- COPY Usage <src> .. <test>
ENTRYPOINT
- Configuration command after starting the container, and may not be covered docker run parameters supplied, and CMD can be covered. If you need to cover, you can use docker run --entrypoint
- Each Dockerfile can have only one ENTRYPOINT, when you specify more, only the last one will work
- ENTRYPOINT usage
1.ENTRYPOINT "exectable","param1","param2"
2.ENTRYPOINT command param1 param2(shell from)
VOLUME
- VOLUME effect is to mount the machine to the target directory vessel or other container mount mount mount point to the target vessel
- Usage VOLUME: VOLUME [ "/ data"]
USER
- UID specifies the user or when the container is running, subsequent RUN, CMD, ENTRYPOINT also specified user
- USER usage: USER daemon
WORKDIR
- WORKDIR for subsequent RUN, CMD, ENTRYPOINT instructions to configure the working directory. WORKDIR plurality of instructions may be used, if the follow-up parameter is a relative path command, it specifies based on the previous command path
- WORKDIR used as follows:
##例1
WORKDIR /a
WORKDIR b
WORKDIR c
RUN pwd
最终路径为/a/b/c
##WORKDIR指令可以在ENV设置变量之后调用环境变量
ENV DIRPATH /path
WORKDIR $DIRPATH/$DIRNAME
最终路径为/path/$DIRNAME
ONBUILD
- ONBUILD usage: ONBUILD [INSTRUCTION]
- Dockerfile using the generated image A, does not perform ONBUILD command again if there is a DOckerfile image A as the base image to generate the image B will execute the command ONBUILD
