Procfiles are a simple manifest format that describes processes. Here's an example:
web: node run dev
api: go run ./server
Each line contains a process name and a command to execute separated by a colon and some whitespace.
When a process is started, a unique
PORTenvironment variable is supplied to each.
Most procfile runners, Exo included, have a single command to start all processes in the procfile, then tail their logs until interrupted:
exo run Procfile
Video demonstration of using Exo with a Rails application configured via a Procfile.