Playing with Docker and its fun !!!
1. Update your system up to the current patch level
# yum -y update
2. Install ducker package.
# yum -y install docker docker-registry
3. Start Docker and enable it to run upon reboot
# systemctl enable docker.service
ln -s '/usr/lib/systemd/system/docker.service' '/etc/systemd/system/multi-user.target.wants/docker.service'
# systemctl start docker.service
4. Verify that the docket service is starting
# systemctl status docker.service
docker.service - Docker Application Container Engine
Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled)
Active: active (running) since Tue 2015-01-27 21:59:53 EST; 37s ago
Docs: http://docs.docker.com
Note: you can add local user to use docket.
# id jay
uid=1001(jay) gid=1001(jay) groups=1001(jay)
# getent group docker
docker:x:990:
# usermod -aG docker jay
# id jay
uid=1001(jay) gid=1001(jay) groups=1001(jay),990(docker)
5. Download the docker container from Docker Index
# docker pull centos
Pulling repository centos
8efe422e6104: Download complete
511136ea3c5a: Download complete
5b12ef8fd570: Download complete
Status: Downloaded newer image for centos:latest
6. Verify that the images have been fetched locally.
# docker images centos
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
centos centos7 8efe422e6104 3 weeks ago 224 MB
centos latest 8efe422e6104 3 weeks ago 224 MB
centos 7 8efe422e6104 3 weeks ago 224 MB
7. Run a basic cat command using the docker.
# docker run centos:centos7 cat /etc/centos-release
CentOS Linux release 7.0.1406 (Core)
8. Run the docker container
[root@localhost ~]# docker run -i -t centos /bin/bash
Note: -i attaches stdin and stdout, -t allocates a tty
[root@b01e2e6f2688 /]# pwd
/
[root@b01e2e6f2688 /]# ls
bin etc lib lost+found mnt proc run selinux sys usr
dev home lib64 media opt root sbin srv tmp var
[root@b01e2e6f2688 /]# pwd
/
[root@b01e2e6f2688 /]# cat >/test.file
This is created under docker centos
[root@b01e2e6f2688 /]#
To get out off the container ( To disconnect, or detach, from the shell )
use escape sequence Ctrl-p + Ctrl-q.
[root@b01e2e6f2688 /]#
type ctrl +p and ctrl q to exit out off the docker. or you can use the exit command
[root@localhost ~]# cat /test.file
cat: /test.file: No such file or directory
[root@localhost ~]#
9. To search the docker available, use the docker search command.
[root@localhost ~]# docker search centos
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
centos The official build of CentOS. 768 [OK]
[root@localhost ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
b01e2e6f2688 centos:7 "/bin/bash" 7 minutes ago Up 7 minutes sad_elion
a7ce8ce380b8 centos:7 "cat /etc/centos-rel 9 minutes ago Exited (0) 9 minutes ago clever_brattain
Attach a docker container
[root@localhost ~]# docker attach b01e2e6f2688
[root@b01e2e6f2688 /]#
Install git on the server
[root@b01e2e6f2688 /]# yum install git
Complete!
[root@b01e2e6f2688 /]# git --version
git version 1.8.3.1
[root@b01e2e6f2688 /]# git config --global user.name "jay"
[root@b01e2e6f2688 /]# git config --global user.email "jay@sama.expanor.local"
[root@b01e2e6f2688 /]#
[root@b01e2e6f2688 /]# cd /opt
[root@b01e2e6f2688 opt]# cd
[root@b01e2e6f2688 ~]# cat .gitconfig
[user]
name = jay
email = jay@sama.expanor.local
[root@b01e2e6f2688 ~]#
or
[root@b01e2e6f2688 ~]# git config --list
user.name=jay
user.email=jay@sama.expanor.local
Disconnect, or detach, from the Docker shell
CTRL+p; CTRL+q
Commit changes to Docker
[root@localhost ~]# docker commit b01e2e6f2688 my-centos-with-git
2dd94bb41bf4b96d569aed1cc5f353282e7c40bbea3948146c841c4dddeb2df7
Check the logs on the dockers
[root@localhost ~]# docker logs b01e2e6f2688 | more
Search other available dockers.
[root@localhost ~]# docker search ubuntu
[root@localhost ~]# docker pull ubuntu
Pulling repository ubuntu
b39b81afc8ca: Download complete
511136ea3c5a: Download complete
53f858aaaf03: Download complete
837339b91538: Download complete
615c102e2290: Download complete
Status: Downloaded newer image for ubuntu:latest
[root@localhost ~]#
root@localhost ~]# docker pull fedora
Pulling repository fedora
834629358fe2: Download complete
511136ea3c5a: Download complete
00a0c78eeb6d: Download complete
Status: Downloaded newer image for fedora:latest
[root@localhost ~]#
[root@localhost ~]# docker images fedora
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
fedora 21 834629358fe2 3 weeks ago 250.2 MB
fedora latest 834629358fe2 3 weeks ago 250.2 MB
[root@localhost ~]#
[root@localhost ~]# docker images ubuntu
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
ubuntu 14.04 b39b81afc8ca 11 days ago 192.7 MB
ubuntu 14.04.1 b39b81afc8ca 11 days ago 192.7 MB
ubuntu latest b39b81afc8ca 11 days ago 192.7 MB
ubuntu trusty b39b81afc8ca 11 days ago 192.7 MB
[root@localhost ~]#
Login to UbuntU docker.
[root@localhost ~]# docker run -i -t ubuntu /bin/bash
root@0303170b0c59:/# pwd
/
root@0303170b0c59:/# cat >/test.me
This is docker UbuntU
root@0303170b0c59:/# df -h .
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/docker-253:1-3149016-0303170b0c59d20c65b4babfc755be19bb42809a932fd848790cfacfbde1590c 9.8G 245M 9.0G 3% /
root@0303170b0c59:/#
[root@localhost ~]# cat /test.me
cat: /test.me: No such file or directory
[root@localhost ~]#
[root@localhost ~]# su - jay
[jay@localhost ~]$ docker ps -l
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0303170b0c59 ubuntu:14.04 "/bin/bash" 2 minutes ago Exited (0) About a minute ago stoic_wozniak
[jay@localhost ~]$
