Develop Reference

heroku application error for fastapi (python)

I followed github/stackoverflow resources, watched youtube videos, read heroku official docs but in the end, I still getting error (network erro). Can someone help me what is the problem going on with my project?
I upoloaded project in github and linked with heroku. Used environment variable as heroku config vars with database strings, projects with project secret keys etc.
My requirements.txt file below
appdirs
typing
dnspython
email-validator
fastapi
motor
datetime
jose
passlib
dataclasses
typing-extensions
pydantic
starlette
uvicorn
bson
gunicorn
h11
click
pylint
astroid
websockets
In Procfile I wrote this in each different commits
web: gunicorn -w 4 -k uvicorn.workers.UvicornWorker main:app
and then this
web: uvicorn main:app --host=0.0.0.0 --port=${PORT:-5000}
and this
web: uvicorn main:app --host="0.0.0.0" --port=${PORT:-8000}
and also
web: uvicorn main:app --host "0.0.0.0" --port ${PORT}
but none of them are workable.
and also updated runtime.txt file several time with different python versions.
May be I tried every possibilities from internet but what is the god damn problem ?

You must check the logs by running this command from your terminal.
"heroku logs --tail -a [applicationname]".
In my case the issue is this "pip install "pymongo[srv]" which I found from the logs. In the solution is to add this "dnspython==2.1.0" in the requirements.txt and redeploy.

Can't get heroku procfile

I'm trying to build up a deep-learning-based facebook chatbot (using Python). I'm trying to deploy it on Heroku firstly, but as I'm using the command web: gunicorn echoserver:app the terminal says web: command not found. Howevere, I've installed gunicorn already.

This is because you are typing web:, which is not a command line interface (CLI) command.
If you've installed gunicorn, then the command (from the CLI) is gunicorn. Something like, for instance
gunicorn echoserver:app
I suppose it's also possible that you have a Windows machine. gunicorn does not work on Windows, so you would need to use something like waitress. With waitress, you would type web: on a Windows machine, so that it would be something like
web: waitress-serve echoserver:app

Note that the procfile is literally a file you place in your repository. The contents of the procfile should contain the command you want Heroku to run to start your server.
So in the root directory of your repo, you should have a Procfile (named exactly that with no file extension) with the following contents:
web: gunicorn echoserver:app
The first part (web:) is just used to tell Heroku which dyno to run the second part (the command) on. So Heroku will only run the command on web dynos and not on background dynos.
More info here: https://devcenter.heroku.com/articles/procfile

Heroku not reading requirement.txt file

I am trying to deploy my python flask app to heroku but it keeps crashing and complaining about bash: gunicorn: command not found. I have my requirement.txt file in the root folder where my Procfile is also located. My python code is located in src/server/
Procfile contains: web: gunicorn --pythonpath src/server/ route:app --preload
I have gunicorn in my requirements file:
Is there something i'm missing?
gunicorn==19.8.1
Flask==0.12.2
Flask-Cache==0.13.1
Flask-Cors==3.0.2
Flask-MongoAlchemy==0.5.1
flask-mongoengine==0.9.5
Flask-PyMongo==0.5.2
Flask-WTF==0.14.2
gevent==1.2.1
greenlet==0.4.12
pymongo==3.6.1
folder structure;

I faced a similar problem with my app. I just reset all my requirements by sending in an empty requirements.txt file. Then built my app. Then sent the original file. I don't understand why, but it worked.

I am also having a similar problem like this on Heroku. I created an IDENTICAL new project and magically it works. Heroku has some bug related to ignoring requirements.txt

I fixed it by creating a new environment in Heroku. The previous environment seems not to be reading the requirement.txt file, I couldn't figure why.

Couldn't find that process type, Heroku

I'm trying to deploy a simple python bot on Heroku but I get the error
couldn't find that process type
When I try to scale the dynos. I already made a procfile and it looks like this:
web: gunicorn dep:app, where "dep" is the name of my python code
What could be the reason?

This may happen if your procfile is misspelt, such as "procfile" or "ProcFile" etc. The file name should be "Procfile" (with a capital P).
sometimes changing the file name is not anough, because git wouldn't spot the change. I had to delete the Procfile completely, then commit the change, than add it again with the right name, and then commit that again:
remove your procfile
git commit
add a new procfile with the exact name "Procfile"
commit again
git push heroku master (or main - new heroku projects now uses main)
should work!

Make Sure Procfile should not have any extension like .txt
otherwise this will be the error
remote: -----> Discovering process types
remote: Procfile declares types -> (none)
To create file without extension type following in cmd
notepad Procfile.
Now add web: gunicorn dep:app and save
Now when you will git push heroku master the above lines will be like
remote: -----> Discovering process types
remote: Procfile declares types -> web
And the error is gone when you will run
C:\Users\Super-Singh\PycharmProjects\URLShortener>heroku ps:scale web=1
Scaling dynos... done, now running web at 1:Free

Ensure that the Procfile is in the root directory of your repository.
In my case I had initially kept the Procfile in a subdirectory. Moving it to the root directory solved the problem.
For people who are trying to deploy a django web app, take note that the above step may cause another issue - of heroku unable to reach till the wsgi file residing in the subdirectory.
I solved it by referring to the below thread -
How can I modify Procfile to run Gunicorn process in a non-standard folder on Heroku?

The following worked for me.
As per this Heroku help page:
To fix:
Remove the existing buildpacks with heroku buildpacks:clear.
You will need to add an empty commit and redeploy for the changes to
take effect:
git commit --allow-empty -m "Adjust buildpacks on Heroku"
git push heroku master

You might check your python version. I tried to deploy my Django project so my procfile looks like this web: gunicorn blog.wsgi --log-file - and I also got the same error couldn't find that process type. and I found that Heroku only support python-3.6.4 and python-2.7.14 while I just had python3.5. You can type:
python -V
to see what python version you are using now. if not, you can download python 3.6. I followed this How do I install Python 3.6 using apt-get?
Ubuntu 14.04 and 16.04
If you are using Ubuntu 14.04 or 16.04, you can use Felix Krull's
deadsnakes PPA at
https://launchpad.net/~deadsnakes/+archive/ubuntu/ppa:
sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get update
sudo apt-get install python3.6
Alternatively, you can use J Fernyhough's PPA at
https://launchpad.net/~jonathonf/+archive/ubuntu/python-3.6:
sudo add-apt-repository ppa:jonathonf/python-3.6
sudo apt-get update
sudo apt-get install python3.6
and remember to keep you python 3.5. Don't remove it. and specify your python version in the runtime.txt file: python-3.6.4 and run:
heroku ps:scale web=1 --app [my app's name]
and the problem solved. I hope my answer might help you.

In My case the error was solved by just creating space between web and gunicorn
Before:
web:gunicorn --pythonpath app app.wsgi
After:
web: gunicorn --pythonpath app app.wsgi

While it's not Python, in my case, I had heroku/java followed by heroku/pgbouncer. In Heroku's Settings, I switched them so heroku/pgbouncer was on top. This fixed the issue. Perhaps your buildpacks need to be ordered differently if you are using multiple.

Heroku local invalid port number or address:port pair - deploying django app

I have this ProcFile file following this guidelines for django app deployment on section Build your app and run it locally in order to test it locally you have to run this command.
web: python manage.py runserver 0.0.0.0:$PORT
Then running heroku local or heroku local web got me into this error:
CommandError: "0.0.0.0:$PORT" is not a valid port number or address:port pair.

You must not use runserver in production. Use gunicorn as the docs and comments suggest.

For local:
If you follow this official heroku tutorial and you are running it on Window platform locally, instead of $PORT, you have to use %PORT% at your Procfile.windows:
web: python manage.py runserver 0.0.0.0:%PORT%
since window does not interpret $PORT expression which only applicable in Unix shells.
If one using waitress as WSGI and wanna run it locally on Window platform, your Procfile should looks like this:
web: waitress-serve --port=%PORT% wsgi:your_app
For real online deployment:
simply include gunicorn package in requirementx.txt and your Procfile should be in this way:
web: gunicorn wsgi:your_app
If you are using waitress, you need to change back to $PORT, and set it in this way instead of fixed port number since Heroku assigns port to your app dynamically. Also, do make sure the host is set to 0.0.0.0 so your app is available externally.

For a django project in heroku you must have a Procfile like this:
web: gunicorn yourapp.wsgi
The filename must be Procfile, and not ProcFile
If you want to run into development you can either $ python manage.py runserver in your shell (heroku independent) or run $ heroku local with a valid production Procfile