How to build your own ubuntu image with docker?
How to build your own ubuntu image with docker?
一. Build a ubuntu image and install sshd
1. Pull ubuntu
docker pull ubuntu:14.042. Create Dockerfile
FROM ubuntu:14.04
#update
RUN apt-get update
#install gcc
RUN apt-get install -y gcc
#install vim
RUN apt-get install -y vim
#install sshd
RUN apt-get install -y openssh-server
RUN mkdir /var/run/sshd
#create user
RUN useradd admin
RUN echo 'admin:admin' |chpasswd
#start sshd
EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]3. Build image
docker build -t ubuntu-sshd-admin .
Build then check image.
$ docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu-sshd-admin latest 82a9040e58aa 14 minutes ago 380MB4. Run
docker run -d -p 222:22 ubuntu-sshd-admin
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d87645ff3fa2 ubuntu-sshd-admin "/usr/sbin/sshd -D" 7 minutes ago Up 7 minutes 0.0.0.0:222->22/tcp unruffled_mirzakhani5. Client test
ssh admin@127.0.0.1 -p 222
Use admin:admin to login, then you will find sshd is already started.
$ ps -elf | grep sshd
4 S root 1 0 0 80 0 - 15346 - 04:05 ? 00:00:00 /usr/sbin/sshd -D
4 S root 22 1 0 80 0 - 23138 - 04:13 ? 00:00:00 sshd: admin [priv]
5 S admin 33 22 0 80 0 - 23138 - 04:13 ? 00:00:00 sshd: admin@pts/0
0 S admin 37 34 0 80 0 - 2219 - 04:14 pts/0 00:00:00 grep sshd
$ 二. Install more software
1. Create new Dockerfile
If you need more software in your own system, you can create more Dockerfile and build update version of image.
For example, if you want to install vim, you can write a new Dockerfile.vim
FROM ubuntu-sshd-admin
#install vim
RUN apt-get install -y vimAnd now we have two dockerfiles.
2. Build a new version
docker build -t ubuntu-sshd-admin:0.1 . -f Dockerfile.vim
By exec the cmd above, we can build a new version of ubuntu-ssh-admin, we can check by this:
$ docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu-sshd-admin 0.1 dbea46204d20 8 minutes ago 414MB
ubuntu-sshd-admin latest 82a9040e58aa 3 hours ago 380MBThen we can restart the container and see vim is already installed in the ubuntu.
docker run -d -p 222:22 ubuntu-sshd-admin:0.1
三. Create a volume for ubuntu
1. create a volume
wangyachangdeMacBook-Pro:docker wangyachang$ docker volume create ubuntu
ubuntu
wangyachangdeMacBook-Pro:docker wangyachang$ docker volume inspect ubuntu
[
{
"CreatedAt": "2018-06-21T07:31:06Z",
"Driver": "local",
"Labels": {},
"Mountpoint": "/var/lib/docker/volumes/ubuntu/_data",
"Name": "ubuntu",
"Options": {},
"Scope": "local"
}
]2. start ubuntu
Then we can start the ubuntu image by mount /world to the volume created before.
wangyachangdeMacBook-Pro:ubuntu wangyachang$ docker run -d -p 222:22 --mount type=volume,source=ubuntu,target=/world ubuntu-sshd-admin:0.2
da637a55cb71589f58397a446f00bd5703e7d219e6f12250062c7b13d1dbba48We can can creat a file in the /world directory.
root@1c67af3a9a6e:/# touch /world/data.txt
root@1c67af3a9a6e:/# ls /world/data.txt
/world/data.txt因为作者的docker是安装在mac上的，mac上的docker是在一个虚拟机中运行的，所以这里访问下面这个目录是不存在的。
/var/lib/docker/volumes/ubuntu/_data/Applications/Docker.app/Contents/MacOS/com.docker.driver.amd64-linux
四. 挂载一个主机目录作为数据卷
使用 -v 标记也可以指定挂载一个本地的已有目录到容器中去作为数据卷：
docker run -d -p 222:22 -v /Users/wangyachang/Documents/docker/ubuntu/ubuntu_data:/world_data ubuntu-sshd-admin:0.2
使用上面的命令，会把本机ubuntu_data目录挂载到容器的world_data，实现了所有的数据同步。