From the official Docker Hub image page:
Confluence Server is where you create, organise and discuss work with your team. Capture the knowledge that's too often lost in email inboxes and shared network drives in Confluence - where it's easy to find, use, and update. Give every team, project, or department its own space to create the things they need, whether it's meeting notes, product requirements, file lists, or project plans, you can get more done in Confluence.
Learn more about Confluence Server: https://www.atlassian.com/software/confluence
You can find the repository for this Dockerfile at https://hub.docker.com/r/atlassian/confluence-server
The deploy.yaml uses the official Docker image to deploy a basic configuration of Confluence Server on Akash.