You probably know what you need to do anyways :) Feel free to submit a pull request to improve this page.
- Download: https://www.postgresql.org/download/linux/
- How To Install and Use PostgreSQL on Ubuntu 16.04: https://www.digitalocean.com/community/tutorials/how-to-install-and-use-postgresql-on-ubuntu-16-04
- How To Install and Use PostgreSQL on Ubuntu 18.04: https://www.digitalocean.com/community/tutorials/how-to-install-and-use-postgresql-on-ubuntu-18-04
- Download: https://www.mongodb.com/download-center?jmp=nav#community
- How to Install MongoDB on Ubuntu 16.04: https://www.digitalocean.com/community/tutorials/how-to-install-mongodb-on-ubuntu-16-04
- How to Install MongoDB on Ubuntu 18.04: https://www.digitalocean.com/community/tutorials/how-to-install-mongodb-on-ubuntu-18-04