Docker Part 3

Oct 15, 2024

In this post, we will be looking at the practical use of docker. In case if you have not visited by previous two post about docker, you can check these two post here Docker-Part-1 and Docker-Part-2

1.Docker installation: The installation of docker on every OS different, here we will be looking at installation of docker on Ubuntu 22.04 version. You can have a look on the following link to install docker on different OS.

Set up Docker's apt repository.

# Add Docker's official GPG key:

sudo apt-get update

sudo apt-get install ca-certificates curl

sudo install -m 0755 -d /etc/apt/keyrings

sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc

sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:

echo \

"deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \

$(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \

sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update

Install the latest Docker packages

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Verify that the Docker Engine installation is successful by running the hello-world image.

docker run hello-world

Unable to find image 'hello-world:latest' locally

latest: Pulling from library/hello-world

c1ec31eb5944: Pull complete

Digest: sha256:d211f485f2dd1dee407a80973c8f129f00d54604d2c90732e8e320e5038a0348

Status: Downloaded newer image for hello-world:latest

Hello from Docker!

This message shows that your installation appears to be working correctly.

2.Use the below command to check installed docker version.

docker version

Client: Docker Engine - Community

Version: 27.2.1

API version: 1.47

Go version: go1.22.7

Git commit: 9e34c9b

Built: Fri Sep 6 12:08:10 2024

OS/Arch: linux/amd64

Context: default

Server: Docker Engine - Community

Engine:

Version: 27.2.1

API version: 1.47 (minimum version 1.24)

Go version: go1.22.7

Git commit: 8b539b8

Built: Fri Sep 6 12:08:10 2024

OS/Arch: linux/amd64

Experimental: false

containerd:

Version: 1.7.22

GitCommit: 7f7fdf5fed64eb6a7caf99b3e12efcf9d60e311c

runc:

Version: 1.1.14

GitCommit: v1.1.14-0-g2c9f560

docker-init:

Version: 0.19.0

GitCommit: de40ad0

3.If you want to pull any public image from docker public registry, you can use the below command to pull a public docker image. Here i am pulling latest image of nginx docker.

root@ubuntuserver:/home/superuser# docker pull nginx

Using default tag: latest

latest: Pulling from library/nginx

302e3ee49805: Pull complete

d07412f52e9d: Pull complete

9ab66c386e9c: Pull complete

4b563e5e980a: Pull complete

55af3c8febf2: Pull complete

5b8e768fb22d: Pull complete

85177e2c6f39: Pull complete

Digest: sha256:d2eb56950b84efe34f966a2b92efb1a1a2ea53e7e93b94cdf45a27cf3cd47fc0

Status: Downloaded newer image for nginx:latest

docker.io/library/nginx:latest

root@ubuntuserver:/home/superuser#

4.Now you can launch the container using nginx docker image using below command, I will running the container in in detach mode using -d command and port no 80.

root@ubuntuserver:/home/superuser# docker run -d --name mynginx -p 8080:80 nginx

383cb1b644d31370a7e009fa6117d4c7117bc500290869c12f7ae444c2527528

The above command launched a nginx container name mynginx in detach mode. The -d parameter is use to run container in detach mode. -p is for port mapping. By default nginx listen on port 80 so we mapped port 8080 of host to nginx container 80. You can access the nginx web server using your host ip address and port 8080 in your browser like below.