[Python] Setup environment to run python webapps

sirlinux · 02-16-2021, 02:14 AM

I created with Vmware workstation an Ubuntu 20.04 server VM in which I also installed LAMP in order to run my little php/mysql projects. It works fine.
I started learning python as well, and I'd like now to develop little webapps which run in my browser (I flask too, I guess), the way I do with my php files.
Unfortunately, I haven't yet understood how to create a python server/environment to run my projects in my browser. I read plenty of articles about that, but each and every of them said somethign different, and, as a result, I am more confused than I was.
Could you help me figure it out please?
Thanks

pan64 · 02-16-2021, 02:21 AM

I guess you are speaking about python venv (but not really sure).

sirlinux · 02-16-2021, 02:38 AM

Quote:

Originally Posted by pan64

I guess you are speaking about python venv (but not really sure).

I'm not sure either

boughtonp · 02-16-2021, 06:53 AM

I don't think you're asking about venv stuff - which I believe is for isolating dependencies of different applications (so still something you might want, but it wont solve the server aspect).

When I tried to figure this out, I first resorted to simply using Jetty FastCGI to connect to a Python script which manually printed HTTP responses - basically "import cgi,cgitb,os,sys" then parsing "os.getenv('PATH_INFO',''") and "os.getenv('QUERY_STRING','')" to figure out what to do, and finally sending the HTTP response with "sys.stdout.write"

It's not a great approach - in particular it means re-starting the application on every request - but it did allow me to just get started on the important code.

Later I came back and wrote a basic WSGI server for the app using wsgiref.simple_server.make_server, which runs the server+application continually until stopped.

I still need to return to that project at some point and figure out if that's an appropriate solution - I remember vague warnings about it only being for "evaluation purposes" or some similar nonsense, so need to confirm whether it's enough to put Jetty/Apache/nginx/etc in front of it, or whether I need yet another approach.

sirlinux · 02-16-2021, 08:45 AM

Quote:

Originally Posted by boughtonp

I don't think you're asking about venv stuff - which I believe is for isolating dependencies of different applications (so still something you might want, but it wont solve the server aspect).

When I tried to figure this out, I first resorted to simply using Jetty FastCGI to connect to a Python script which manually printed HTTP responses - basically "import cgi,cgitb,os,sys" then parsing "os.getenv('PATH_INFO',''") and "os.getenv('QUERY_STRING','')" to figure out what to do, and finally sending the HTTP response with "sys.stdout.write"

It's not a great approach - in particular it means re-starting the application on every request - but it did allow me to just get started on the important code.

Later I came back and wrote a basic WSGI server for the app using wsgiref.simple_server.make_server, which runs the server+application continually until stopped.

I still need to return to that project at some point and figure out if that's an appropriate solution - I remember vague warnings about it only being for "evaluation purposes" or some similar nonsense, so need to confirm whether it's enough to put Jetty/Apache/nginx/etc in front of it, or whether I need yet another approach.

I found this:

https://projects.raspberrypi.org/en/...r-with-flask/1

I did what it says step by step and it works now, I mean, I have that "Hello world" message in my browser.
However, I am trying to figure out if there is a way to get it better than that since I got:

Code:

john@ubuntu-02:~/webapp$ python3 app.py
 * Serving Flask app "app" (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: on
 * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)

when I ran python3 app.py in my linux shell.
Futhermore, am I supposed to run the same command everytime I reboot the server?

Your thoughts, please.

Thanks

dugan · 02-16-2021, 09:24 AM

You’re using Apache?

https://flask.palletsprojects.com/en...ying/mod_wsgi/

https://www.google.com/amp/s/www.dig...ubuntu-vps.amp

sirlinux · 02-16-2021, 09:38 AM

Quote:

Originally Posted by dugan

You’re using Apache?

https://flask.palletsprojects.com/en...ying/mod_wsgi/

https://www.google.com/amp/s/www.dig...ubuntu-vps.amp

Yes, of course. As I said, I installed LAMP on that linux machine, so I already have Apache, PHP, and mysql running on it.

Interesting links, I'll read them through.

Thank you