What is Docker..?
Docker is an open-source project that automates the deployment of applications inside software containers, by providing an additional layer of abstraction and automation of operating-system-level virtualization on Linux. Docker uses resource isolation features of the Linux kernel such as cgroups and kernel namespaces to allow independent “containers” to run within a single Linux instance, avoiding the overhead of starting and maintaining virtual machines.
The Linux kernel’s support for namespaces mostly isolates an application’s view of the operating environment, including process trees, network, user IDs and mounted file systems, while the kernel’s cgroups provide resource isolation, including the CPU, memory, block I/O and network. Since version 0.9, Docker includes the libcontainer library as its own way to directly use virtualization facilities provided by the Linux kernel, in addition to using abstracted virtualization interfaces via libvirt, LXC (Linux Containers) and systemd-nspawn.
In Simple words Docker is a Process based Virtualization Software. It uses process instead of any hypervisors.
There are five of the docker tutorial:
Part 1 : Installation and Configuration of Docker in Centos/Redhat & Fedora
Part 2 : Installation and Configuration of Docker in Ubuntu
Part 3 : Basic Docker Commands
Part 4 : How to run Container in Docker
Part 5 : How to take Backup & Restore of Docker Container
Install Docker on Centos Redhat & Fedora
Step 1 : Prerequisite for docker
Install EPEL Repo for your Distribution use following command to install epel:
yum install epel-release
Step 2 : Install docker
yum install docker -y
Another Method for installing Docker by docker repo
Step 3 : Make a file in /etc/yum.repos.d with name docker.repo:
vim /etc/yum.repos.d/docker.repo
[dockerrepo]
name=Docker repository
baseurl=https://yum.dockerproject.org/repo/main/centos/$releasever/
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
Step 4 : Install Docker
yum install docker-engine -y
Step 5 : Start service of docker
On Centos/Redhat 7
systemctl start docker
systemctl enable docker
On Centos/redhat 6
service start docker
chkconfig docker on
Step 6 : Using Docker
Now docker is successfully installed you can start using docker
Use following command to check the available images
docker images
That is all about installing docker in Centos/Redhat & Fedora in our next tutorial we will learn how to install docker in ubuntu and use docker.
If you have any problem in using this tutorial feel free to comment below..