WARNING! Before you start, it is recommended that you have a good understanding of Blesta and Docker. This quick start will be going through with using docker-compose.
First make sure that your docker build is up to date (At the time, this works on Docker CE 17.x).
Clone/Download the repository to your local storage.
Rename the provided .env.example as .env
Edit variables to fit your need, such as database password and URL.
Run docker-compose pull to pull down the images. After docker-compose up -d mysql to start up mysql (Be sure to wait roughly 10-30 seconds to ensure that the database starts up).
When the base is set up, then run docker-compose up -d blesta. This may take anywhere from 30 seconds to a few minutes when the panel starts up.
Now login to blesta using the your domain.com/admin and set up Blesta
If you have any problems, refer to docker-compose logs to identify any issues.
You should be all set and rocking!
Refer to https://docs.blesta.com/display/user/Upgrading+Blesta when updating to a newer version.
Let's Encrypt is supported, just add in certbot from docker-compose.extra.yml and volumes to panel.