When I run heroku ps:scale web=1
It tell me Scaling dynos... done, now running web at 1:Basic
But then when I run heroku ps
I get No dynos on ...
As a result my app isn't running, I get these logs heroku[router]: at=error code=H14 desc="No web processes running" method=GET
This happens after successfully deploying a build that upgrades my stack from 18 to 20
After opening a ticket on Heroku, here is the solution from them:
Thanks for reaching out to us. Due to some issue in heroku-cli ps:scale command is not working properly on heroku-cli (we have informed it to engineering team) Please go to https://dashboard.heroku.com/apps/APP_NAME/resources page and :-
click on Pencil icon near Dyno information and slide down to 0 then confirm.
click on Pencil icon near Dyno information and slide up to 1 then confirm.
Run: heroku ps -a APP_NAME on cli and check whether it worked or not.
On my side there was no slider but a toggle button to toggle the dynos on and off.