Dockerization

4 min readMar 30, 2023

I have been using Dockers for a while now, in almost every project that I have made. Here is a gist of what I have learned so far!

What are Dockers?

Docker is a software platform that allows you to build, test, and deploy applications quickly.

Firstly, how I came across Dockers?
I was working on a backend project and I had to deploy it on a Digital Ocean droplet. I was honestly tired of setting up the project and installing all dependencies again, this is when i came across Dockers.

What are containers and how are they different from VMs?

A container is a software code package containing an application’s code, its libraries, and other dependencies. Containerization makes your applications portable so that the same code can run on any device. Thus, processes running inside containers are visible from the host system (given enough privileges for listing all processes).

A Docker packages an application and all its dependencies in a container that can only run on a Linux Server. Thus, dockers are also called containers.

Instead of setting up the project from scratch, and installing all dependencies, Docker bundles up the code along with its dependencies into autonomous container units.

Whereas, a virtual machine is a digital copy of a physical machine. Everything running inside the VM is independent of the host operating system, or hypervisor. The virtual machine platform starts a process (called virtual machine monitor, or VMM) in order to manage the virtualization process for a specific VM, and the host system allocates some of its hardware resources to the VM.

A hypervisor(sometimes also referred to as Virtual Machine Monitor) is software that creates and runs virtual machines (VMs). It isolates the hypervisor operating system and resources from the virtual machines and enables the creation and management of those VMs.

How Components does a Docker need?

Daemon — which is used to build, run, and manage the container.
High-level API — which allows the user to communicate with the Daemon
CLI — an interface we use to make this all available.

Steps for Dockerization

These are the steps required to set up dockers in WSL.
Make sure your WSL is upgraded to version 2.

If you do not have docker installed, Try installing using Docker Desktop as

Here is a list of basic commands to make sure the docker is up and running

To start the docker daemon

sudo dockerd

2. To check the current version of the docker

docker version

Incase you get any permission denied error, try running the same command using sudo

3. To pull an image
A Docker image is a read-only template that contains a set of instructions for creating a container that can run on the Docker platform.
Here ‘hello-world’ is a sample docker image. Using this command, we pull an image from the Docker Hub, you can list all available images using

docker image ls
docker pull hello-world
docker pull redis

4. To check the list of containers that are already running on your system

docker ps

5. To check the list of all containers

docker ps -a

6. To containerize an image

docker run redis

7. To remove an image

docker rmi -f redis

8. To pull a specific image version from the docker hub and containerize it

docker run redis:4.0

9. To run docker in detached mode
You can run a container in the background using detcahed mode, this ensures that the applications that are running inside your container are able to run unattended.

docker run -d redis:4.0

10. We can use this id to start and stop a docker
You can see the <id> by running “docker ps” command

docker start <id>
docker stop <id>

11. Port Binding

docker run -p6000:6379 redis

12. To delete an image, we need to stop the container and remove its container first

docker ps
docker stop <Container_Id>
docker rm <Container_Id>
docker image rm <Image_Id>

This is how a sample docker file should look like —
Include this Dockerfile into your project directory

Steps

Build the image

docker build . -t <your username>/<name-of-node-application>

2. Incase of network timeout error

docker build . -t <your username>/<name-of-node-application> --network=host

To see the images listed by Dockers

docker images

Run the image

docker run \
    -it \
    --rm \
    -v ${PWD}:/app \
    -v /app/node_modules \
    -p 3001:3000 \
    -e CHOKIDAR_USEPOLLING=true \
    <your username>/<name-of-node-application>

Print app output

docker logs <container id>

To get container-id

docker ps

To call app using curl

curl -i localhost:49160

You can check out how to integrate the sample react app and sample node js with docker here!

Thank you for reading this blog! I will be posting more on Dockerization very soon ❤

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Feel free to get in touch with me or email me at vidhik2002@gmail.com!