02. Basic Usuage - Images

The docker will download image from remote repository during run a container based on a not existing image locally. The Docker hub is the public image repository.

List all local images

docker images

Pull a new image from remote repository

docker pull ubuntu:13.10

Search Images

docker search httpd

delete images

docker rmi hello-world

Create an Image

1. From a container

Update an image from a modified container
docker commit -m="has update" -a="runoob" e218edb10161 runoob/ubuntu:v2

• -m: the commit comments
• -a: specify the image author
• e218edb10161: container id
• runoob/ubuntu:v2: the new name of the created image

2. build

Using the docker build to build an image. The Dockerfile is needed to tell how to build an image.

FROM    centos:6.7
MAINTAINER      Fisher "fisher@sudops.com"

RUN     /bin/echo 'root:123456' |chpasswd
RUN     useradd runoob
RUN     /bin/echo 'runoob:123456' |chpasswd
RUN     /bin/echo -e "LANG=\"en_US.UTF-8\"" >/etc/default/local
EXPOSE  22
EXPOSE  80
CMD     /usr/sbin/sshd -D

FROM to specify the source of image.
RUN tell the commands in docker image.

Finally using the following command to build an image docker build -t runoob/centos:6.7 .

• -t: the new image name
• .: the folder of Dockerfile

Setup image tag

docker tag <image id> <imagename>:<image tag>

Reference

Tutoriaspoint