Docker - 2

In this article you will learn dockerization process and how to use docker.

There are 3 steps to conatinarize an application:

1. Create a DockerFile

2. Build and image using DockerFile

3. Run the image into a container

STEP 1: Create a DockerFIile

DockerFile: This is a blueprint of an image. A dockerfile consists of all the instructions to build the image.

• It consists of base image, application code, dependencies, and commands to run the application.

• Example:

• 

STEP 2: Build the IMAGE using dockerfile

Image: A lightweight, standalone, and executable package that includes everything needed to run a piece of software, including the code, runtime, libraries, and environment variables.

• Images are used to create containers.

docker build -t <image_name>:<tag> <path_to_dockerfile>

STEP 3: Run the image using Container

Container: Standardized unit of software that packages code and its dependencies, ensuring that applications run quickly and reliably across different computing environments.

docker container run [OPTIONS] IMAGE [COMMAND] [ARG...]

Example: docker run -it ubuntu

The above command runs a ubuntu in a container and enter bash into its terminal(-it <interactive>) .

Basic Docker commands:

1. Pull an docker image: docker pull <image_name>

2. Show running containers - docker ps

3. Show all containers: docker ps -a

4. Stop a conatainer - docker stop <container_name>

5. Show all images- docker images / docker image ls

6. Delete an image - docker rmi <name or image_id>

7. Remove unused images - docker system prune

8. Port mapping - docker run -p host_port:contontainer_port imag