How to run a simple python script on heroku without flask/django? - python

I'm trying to run a simple hello world python program on my heroku server. I'm new to heroku.I was able to successfully deploy my script to heroku.
My python script and procfile are given below,
hi.py
print("hello world")
Procfile
web: python hi.py
I got "Hello world" as output when i ran heroku run web on my terminal.But when i try to run the app using heroku web url it shows the following error.
Application Error An error occurred in the application and your page
could not be served. Please try again in a few moments.
What did i do wrong here? I'm newbie to heroku & its concepts, please do bare.

There are three types of dyno configurations available on Heroku:
Web -- receives web traffic.
Worker -- keeps processing tasks/queues in the background.
One-off -- executed once. e.g.: backup.
If you're interested in running a script, do not care about receiving web traffic on it, and don't have a queue to process, then One-off dynos are likely what you'll want to use. This would be useful for database migrations or backups and whatnot.
Minimal example below.
Sample one-off dyno with Heroku and python AKA “hello world”
This assumes you have already created your app on Heroku and are able to use Herolu CLI from the command-line.
A minimal “hello world” Python script would then look like this. Only 2 files required:
requirements.txt Required, but can be left empty.
task.py with content print("hello world")
Then deploy to Heroku, e.g.:
git add .;
git commit -m "My first commit";
git push heroku master
After that, you'll be able to run your script with heroku run python task.py (and should see the long-awaited hello world in the output.)
If you want to run your program at specific times, use the free Heroku Scheduler add-on.
FYI, Procfile is optional. If you set it to hello: python task.py then you'll be able to run your program with just heroku run hello.
(Note that leaving requirements.txt empty will trigger You must give at least one requirement to install (see "pip help install") warnings on deploy. It's just a warning though and doesn't prevent proper deployment of the program.)

I disagree and state you want flask
main_app.py
import flask
app = flask.Flask(__name__)
#app.route("/")
def index():
#do whatevr here...
return "Hello Heruko"
then change your procfile to web: gunicorn main_app:app --log-file -

Related

Is it possible to have a Heroku app that is just a python console?

I have been writing a pretty simple python quizz system (called game.py) and I am working to deploy it on heroku. The app functions exclusively within the confines of a python console, with no interface of any kind but that provided by a terminal.
As such, I would like to be able to have the application on Heroku simply be akin to what you obtain with a one-off dyno, available on the dashboard (or in a terminal with the CLI) with:
heroku run python game.py
The application works perfectly well in it's deployed form (exclusively from the Heroku git) and locally, but in order for the app to be available to a larger public, I would need to have such a console appear on the "https://[appname].herokuapp.com/" URL that you are given on deployment of the app.
Naively, I would think this to be unspeakably simple to pull off, but I have yet to find a way to do it.
The only reasonable thing I have found would have been to create a Procfile, but lacking any documentation on the commands available, I only have been able to try variations of:
web: run python game.py
Which doesn't create a web console. And:
web: bash
Which simply crash with error code h10, with no other information given.
Any help, any suggestion, any workaround you can think of would be extremely appreciated.

How to run python apps using Procefile on heroku

I've deployed my app on Heroku and run dyno. By default it searches for main.py module and runs it, but I want to specify the folder and app to run. How can I do this?
This is how it's normally works by default
But I want to run app from the "app" folder as it illustrated in the picture
in Procfile we can include our processes and name them as it show in code below
proc_name: python folder_name/app_name.py
And run it on Heroku CLI
heroku ps:scale proc_name=1

Running python flask gunicorn app from shell script

I build my flask app, it requires external files through the runtime.
when I build the app, meaning I run > gunicorn app:app (the app startup file is called app.py but that didn't bother). It runs awesomely.
Now when I decided to make a sort of shell script to execute it (actually to make a couple of dependencies and environment checking but for the sake of simplifying, I created startup.sh in the same directory as app.py and it contains only the following instruction unquoted: "gunicorn app:app"), it just throws errors.
and this is the last one ...
Please help..
yep just as I guessed, it should be run within the script inside a virtualenv so that it will execute python 3 :)

Run a python command from a .yaml file

I have a python project working locally which runs under the UNIX command format of: python main.py arg1 arg2 etc.
I want to export my folder to the Google App Engine, so I did the small tutorial to make "Hello World" run on my App. I read the app.yaml file but can't seem to figure out how to add an app.yaml to my project that runs my Python command.
EDIT:
runtime: python27
api_version: 1
threadsafe: true
command: ["/bin/sh", "-c"]
args: ["python webXMLPARSER.py www.reitmans.com 2016-12-01 2016-12-08"]
The short answer - you cannot do that.
The long one now.
GAE (standard) app code is not designed to run as a standalone app. It is merely a collection of config files and code snippets designed to work together with and complement the GAE infra code (live or SDK) in order to operate as an app.
To run the app locally one must do it through the SDK's development server, see Using the Local Development Server for details.
Also:
GAE apps are fundamentally web server apps, they get requests and return responses, they don't actually execute arbitrary python cmds. Your attempted config is invalid, see app.yaml Reference.
the GAE sandbox has significant restrictions when it comes to what the app can do, in particular launching other processes is not allowed. See The sandbox.
First, you have to instruct to run a shell, and then pass arguments to the shell like python something.py args1 args2.
command: bash -c "python something.py args1 args2"
You should try Dockerfiles1, they have a more intuitive way of running commads:
CMD ["python", "something.py", "args1", "args2"]

Cannot Deploy Pyramid Application on Heroku

I am having issues deploying my Pyramid app on Heroku. It runs fine locally but as soon as I try to launch it I receive this error "pkg_resources.DistributionNotFound: mymedaproject". mymedaproject is the name of my project and is not a python library which is why I am confused. I followed the instructions from this recipe to get to this point:
http://pyramid-cookbook.readthedocs.org/en/latest/deployment/heroku.html
Any ideas?
May be you forgot to put your python project mymedaproject in development mode. What follows is the relevant part of the cookbook recipe.
Create a Procfile
$ echo "web: ./run" > Procfile
Create run with the following:
#!/bin/bash
python setup.py develop
python runapp.py
The first line puts your python project in development mode and enables Paste to load it using your INI file. Make sure Procfile, run, runapp.py and setup.py are in same directory.
References
Getting Started with Python on Heroku
Process Types and the Procfile
Optimization
running a script using a Procfile should work without making it executable
$ echo "web: sh ./run" > Procfile
Check your .gitignore file that it isn't blocking any egg or egg-info information.
If it is, Heroku won't be receiving the egg for your application.

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