
You might not need a CI server to build your Docker Image and push it to Docker Hub.
You can create automated builds directly in Docker Hub.
Basically, it links directly to your repository, and you can manage all the docker image building settings directly from Docker Hub
When already set up, it looks like this in your Docker Hub dashboard:

You can see the automated build details:

You can tweak the build settings and set up different tag names for different branches, even different directories for different Dockerfiles, or build triggers using Webhooks:

Here is a quick getting started:





Just create it, and every change to this repo will trigger new image building directly in Docker Hub. Easy peasy.
You can also plug in webhooks to notify interested systems when the image gets built.

This way you can keep your CI system more focused on just running tests instead of building up and sending your image to Docker Hub. You can notify your Kubernetes cluster (or any kind of server) to update to a newer image using Docker Hub Webhooks.
Hope it has made it clear, there is also some docs around here:
If you have any questions, don’t hesitate to comment down. Cheers! ❤