Dockerizing Express Js App – Part 2

In the previous part, we discussed the basics of Docker and how to create a Dockerfile for an Express Js app. In this part, we will go one step further and dockerize the app by building and running a Docker image.

Building the Docker Image

To build the Docker image for our Express Js app, we need to run the following command in the root directory of the app:

docker build -t express-app .

This command tells Docker to build an image based on the instructions in the Dockerfile in the current directory and tag it as “express-app”.

Running the Docker Image

Once the Docker image is built, we can run it with the following command:

docker run -p 3000:3000 express-app

This command tells Docker to run a container based on the “express-app” image and map port 3000 on the host machine to port 3000 on the container.

Verifying the Docker Container

After running the Docker container, we can open a web browser and navigate to http://localhost:3000 to see our Express Js app running inside the container.

Conclusion

By following the steps outlined in this article, we have successfully dockerized our Express Js app. Docker provides a convenient way to package and run applications in a consistent environment, making it easier to deploy and scale our app. In the next part, we will explore how to deploy the Dockerized app to a cloud platform such as AWS or GCP.