Dockerfile: Building a base ubuntu14.04 image

We can download the image from the official repository from the Docker hub, and I downloaded the Ubuntu image myself, just 188M about, very small. But looked down, the inside of the software source is still official, and is not installed vim , so it is intended to write one Dockerfile , use it to build a suitable for their own Ubuntu base image.

deb http://archive.ubuntu.com/ubuntu/ trusty main restricteddeb-src http://archive.ubuntu.com/ubuntu/ trusty main restricted...................

Build context

build context, a custom folder that contains Dockerfile and some required files. For example, my:

• Dockerfile ... This is a must.
• Sources.list ... The source of the ubuntu14.04 you find in the official community
• VIMRC ... The configuration file to use when Vim is installed. My pre-configured, all are basic configuration.

.├── baseimage│   ├── Dockerfile│   ├── README.md│   ├── sources.list│   └── vimrc

Dokerfile

There are two ways of making an image:

• Create from an existing container by commit command
  
  • Inconvenient operations in Dockerfile can be manipulated in the container and then submitted
  • No need for bulk boot containers
  • Learn and practise without needing to transplant
• Build with Dockerfile
  
  • Convenient, flexible, portable
  • Ideal for deploying a large number of mirrors and containers

Dockerfile Foundation

• ' # ' represents a comment, generally dockerfile the first line of comment container basic information and version.
• Dockerfile 命令：参数 for the basic build statement, command all uppercase, the following parameters are dependent on the command

• From, must be the first command entry, which indicates which image my image is built on.

  FROM ubuntu

• Maintainer, followed by the construction of the name and mailbox, easy to contact

  MAINTAINER adolphlwq <kenan3015@gmail.com>

• LABEL, specifying the metadata for an image in the same way as a key-value pair

  isasforandand install vim." Vendor="Basic image"

• Add, passing files to Docker daemon at build time

  ADD sources.list /etc/apt/

• RUN, connect operations and commands, sudo apt-get install -y vim etc.

  ADD sources.list

• CMD, build a successful image the command started by default when first started

  • CMD only 1, usually by default at the end of Dockerfile
  • If there is more than one cmd, only the last one works
  • CMD will be docker run .. overwritten by the following command
    

    CMD ["/bin/bash"]

• ENV, setting environment variables

  ENV REFRESHED_AT 2015-05-18

Build command

cd baseimage(构建上下文文件夹)docker build -t="duohuosrudio/ubuntu:14.04_64_base_image" .

docker build-tindicates the name of the container
duohuosrudio/ubuntuRepresents the duohuostudio warehouse name (not uppercase), which ubuntu indicates the name of the mirror.
ubuntu:14.04_64_base_imageAfter the 14.04_64_base_image is the label, if not specified, the default islatest

Build process:

Errors encountered in practice

• apt-get upgradeAnd apt-get install vim both to add the *-y* option, or it will be an error
• Add must be followed by two parameters, ADD <src>... <dest> indicating the file to be added, indicating where the file was added.
• The add file must be 构建上下文 found for the root directory and cannot exceed the scope of the build context.

If you stop building and don't worry about it, Docker caches the files in the build process, starting with the cache and saving time.

After the error is stopped, docker images there will be only one IMAGE ID image, this is the cache left after the build failed, we can run the image with the image ID, and then execute the debug command to check why the error! (The last 1 lines)

Adolph@geek: ~/programs/dockerworkspace/dockerfile/baseimage$ Docker imagesREPOSITORY               TAG                   IMAGE ID            CREATED             VIRTUAL SIZETest/ubuntu14.04_64_Base_image e9390454465c -Hours ago269.1 MBTest2/ubuntu14.04_64_Base_image e9390454465c -Hours ago269.1 MBDuohuostudio/ubuntu14.04_64_Base_image e9390454465c -Hours ago269.1 MB<none> <none> f6efc4dac25a -Hours ago269.1 MB

Summarize

-t="duohuostudio/ubuntu:14.04_64_base_image".

The last parameter of this command is used to specify the path of the Dockerfile , never forget it.

Dockerfile has been uploaded to the GitHub address

The image has also been uploaded Docker Hub and can be downloaded via the following command

docker pull adolphlwq/ubuntu

Dockerfile: Building a base ubuntu14.04 image