Dockerlab 103 Working with Docker image
Step 0 : Create docker hub account. https://hub.docker.com
Step 1 : Open Play with Docker or login in below with your docker hub account.
Step 2 : Click on start
Step 3 : It will start a 4 hr session, click on + ADD NEW INSTANCE
Step 4 : Click in terminal and press enter.
Step 5 : docker container run -it ubuntu bash
This command fetches image from docker registry, save it in your system and run container
option i is for interactive session and t is for terminal
Step 6 : apt-get update
apt-get install -y figlet
figlet "hello docker"
update repo and install figlet (it is a program that generates text banners)
figlet and these steps are just an example, you can install any program and modify steps as per your requirement
you will see big hello docker on screen
Step 7 : exit
type exit to come out of container
Step 8 : docker container ls -a
list all containers
Step 9 : docker container diff <container ID>
find difference between initial and updated container
use container id you found in step 8
Step 10 : docker container commit CONTAINER_ID
commit creates a new image locally
use container id you found in step 8
Step 11 : docker image ls
List local images
You will see a new image with no name and tag
Step 12 : docker image tag <IMAGE_ID> firstimage
use image id from step 11
In this step we are naming new image as firstimage
you can also add tags after image name as firstimage:1.0
Step 13 : docker image ls
list all images
new image has name firstimage and tag latest as no tag was provided
Step 14 : docker container run firstimage figlet hello
This will run container from image and use figlet to print big hello on screen