Do I first need docker environment before starting my project?

Question

I am going to work with Node.js and PostgreSQL on Linux. I read many hours about how docker actually works. Still I am not sure that is docker environment needed before starting my project or I can use docker after completion of the project?

Answer 1

You can introduce Docker whenever you want. If using multiple servers then you can create a Docker container with one server in it and the other (non-Dockerised solution) makes requests to that.

Or you could Dockerise them both.

Basically, introduce Docker when you feel the time is right.

I like to divide a large project into multiple sections - eg front end web sever, backend authentication server, backend API server 1, backend API server 2, etc.

As each part of the project gets completed, I Dockerise it. The other parts then use the Dockerised solution.

Answer 2

Lets first understand what docker is and how you can use it in your project.

Docker have three core concepts:

1) Docker engine : a lightweight runtime and robust tooling that builds and runs your Docker containers.

2) Docker image : a carbon copy of your project environment including all environment dependencies like base operating system, host entries, environment variables, databases, web/application servers. In your case, Linux distribution of your choice, node.js and required modules, PostreSQL and it's configuration.

3) docker container : can be visualized as an virtual Linux server running your project. Each time you use docker run, a new container is launched from the docker image.

You can visualize a docker-environment as an lightweight virtual machine where you can run your project without any external interference(host entries/environment variables/ RAM/ CPU) from other projects.

So as a developer, you can develop your project on your Dev machine and once it's ready to be pushed to QA/Staging you can build a docker image of your project which then can be deployed on any environment(QA/Staging/Production).

You can launch multiple container from your image on single or multiple physical servers.