I have developed a Flask project, that uses Waitress for production. I have followed this link
The thing is that I don't want to send all the project to the production server. I mean, as an example production in Java, I make .war of the project and run on the Tomcat server.
How can I do this in Python with Flask?
Python is an interpreted language, so there is no need to "build" your code. The reason Java includes a build step is that Java requires compilation. At high level, all you do is put your Python code on a server, installing any pip requirements, and telling Apache/Nginx where to find your code and how to run it.
If you have complex Javascript as part of your code, you may very well have a build step for the Javascript, such as using babel and webpack. But that should be entirely separate from getting the Python side to work.
If you want to protect your code for some reason, you can do that with a code obfuscation or by just deploying the pyc files, but all of these are complex techniques that you should only do if deploying to untrusted servers. See this article for some examples.
As an aside, Flask has a guide for how to configure it with mod_wsgi and Apache: https://flask.palletsprojects.com/en/1.1.x/deploying/mod_wsgi/
Related
I have a Python web application that I want to wrap in Electron. The web application backend is a very slim Flask app that forwarded calls to a Python package that does the processing, and formats the results. We have a React frontend that talks to this backend. We also have a pip based installation, that runs the Flask backend and serves the frontend, so you can pip install run the server and use it from your browser. This is similar to how Pgadmin 4 works.
Since this application is only used by people on their own computers, and never installed on a server, I want to convert it into an Electron app. However, I couldn't figure out how to distribute this application in one setup for Windows, MacOS and Linux. I don't want the users to have to install Python on their computers.
How can I do that?
There is a couple of clues on how to do that, even though I'm still unsure whether all necessary python modules can be bundled easily.
I have a similar case, even though I just want to bundle a prototype in an electron application so I can send it to collaborators for evaluation, without any intent of shipping it to final users.
My list of hints:
https://github.com/matbloch/electron-flask
https://efficientcoder.net/connect-python-3-electron-nodejs-build-desktop-apps/
https://www.techiediaries.com/flask-electron-tutorial/
I really don't see why you need to throw electron in the mix, instead of just using your browser. I reckon that a barebone electron app that serves your page in a single window is going to be 50Mb. The key benefits of electron is that it lets you do system calls (access local files / devices), but if you are running flask you already have this ability.
Your main obstacle is how to distribute the flask app, specifically without installing python - and electron is not going to make things any easier to that respect. You should probably look at pyinstaller which lets you create executables that embed python.
Now, if you're talking of getting rid of python altogether, then indeed you could do that, nodejs has a rich set of libraries for everything os / db-related, even image processing, but it will lack in data science and processing. YMMV.
I have been looking at setting up a web server to use Python and I have installed Apache 2.2.22 on Debian 7 Wheezy with mod_wsgi. I have gotten the initial page up and going and the Apache will display the contents of the wsgi file that I have in my directory.
However, I have been researching on how to deploy a Python application and I have to admin, I find some of it a little confusing. I am coming from a background in PHP where it is literally install what you need and you are up and running and PHP is processing the way it should be.
Is this the same with Python? I can't seem to get anything to process outside of the wsgi file that I have setup. I can't import anything from other files without the server throwing a "500" error. I have looked on Google and Bing to try to find an answer to this, but I can't seem to find anything, or don't know that what I have been looking at is the answer.
I really appreciate any help that you guys can offer.
Thanks in advance! (If I need to post any coding, I can do that, I just don't know what you guys would need, if anything, as far as coding examples for this...)
Python is different from PHP in that PHP executes your entire program separately for each hit to your website, whereas Python runs "worker processes" that stay resident in memory.
You need some sort of web framework to do this work for you (you could write your own, but using someone else's framework makes it much easier). Flask is an example of a light one; Django is an example of a very heavy one. Pick one and follow that framework's instructions, or look for tutorials for that framework. Since the frameworks differ, most practical documentation on handling web services with Python are focused around a framework instead of just around the language itself.
Nearly any python web framework will have a development server that you can run locally, so you don't need to worry about deploying yet. When you are ready to deploy, Apache will work, although it's usually easier and better to use Gunicorn or another python-specific webserver, and then if you need more webserver functionality, set up nginx or Apache as a reverse proxy. Apache is a very heavy application to use for nothing but wsgi functionality. You also have the option of deploying to a PaaS service like Heroku (free for development work, costs money for production applications) which will handle a lot of sysadmin work for you.
As an aside, if you're not using virtualenv to set up your Python environment, you should look into it. It will make it much easier to keep track of what you have installed, to install new packages, and to isolate an environment so you can work on multiple projects on the same computer.
Is there any lightweight mvc webframework which is not necessary to install to the server?
I need something simple, that i could just copy to the shared hosting. And it must handle urls other that localhost/test.py, something like this localhost/Blog/test
You should probably check out Flask or Bottle, two nice Python microframeworks. With an appropriate "main" Python script (to initialize your app and dispatch requests to it) and mod_rewrite rules in place, you can probably get pretty close to your goal of "just copy[ing] to the shared hosting" with nice URLs.
Flask has good documentation on deploying via CGI, which is what you might have to use on your shared host. (If your host supports FastCGI or mod_wsgi, those deployment options would be preferable.)
Checkout web2py. Seems to be about the simplest python based webserver I can think of.
Django might do, it's hefty, but it comes with it's own development server.
web2py includes everything (ssl-enabled web server, sqlite sql based transaction safe database, web based Integrated Development Enviroment, web based database interface) in one package. The web2py binaries for windows and mac also include Python itself. web2py does not require configuration or installation and can run off a usb drive. It was originally developed as a teaching tool for MVC.
checkout https://github.com/salimane/bottle-mvc or https://github.com/salimane/flask-mvc . They are boilerplates that could get you started with controllers, models in separate folders. They are based on bottle and flask micro frameworks, no useless features, they give you the flexibility to plugin whatever modules you want.
To deploy a site with Python/Django/MySQL I had to do these on the server (RedHat Linux):
Install MySQLPython
Install ModPython
Install Django (using python setup.py install)
Add some directives on httpd.conf file (or use .htaccess)
But, when I deployed another site with PHP (using CodeIgniter) I had to do nothing. I faced some problems while deploying a Django project on a shared server. Now, my questions are:
Can the deployment process of Django project be made easier?
Am I doing too much?
Can some of the steps be omitted?
What is the best way to deploy django site on a shared server?
To enable easy Django deployement I would to the following:
Fisrt-time server configuration
Install mod_wsgi which allow you to run in embedded mode OR in daemon mode.
Install python and virtualenv
In your development environment
Use virtualenv. Take a look at mod_wsgi and virtualenv configuration
Install Django your django version (using python setup.py install)
Install your python libs
Develop your project
Every time you want to deploy
Copy your virtual environment to the production server
Just add an Include directive in your httpd.conf file (or use .htaccess) to your project's apache configuration. As stated in mod_wsgi integration with django documentation, one example of how Apache included file could be configured would be:
Alias /media/ /usr/local/django/mysite/media/
<Directory /usr/local/django/mysite/media>
Order deny,allow
Allow from all
</Directory>
WSGIScriptAlias / /usr/local/django/mysite/apache/django.wsgi
<Directory /usr/local/django/mysite/apache>
Order deny,allow
Allow from all
</Directory>
Automating deployement
I would consider using Fabric to automate deployement
Can the deployment process of django project be made easier?
No. You can script some of this, if you want. However, you're never going to install MySQL, MySQLPuthon, mod_wsgi (or mod_python), or Django again.
You will, however, tweak your application all the time.
Am I doing too much?
No. Python (and Django) are not part of Apache. PHP is embedded in Apache. PHP is exactly like mod_python (or mod_wsgi). Just one piece of the pie. (Apparently, some hosts handle the PHP installation for you, but don't handle the mod_wsgi or mod_python installation.)
Can some of the steps be omitted?
No. However, you only do it once.
What is the best way to deploy django site on a shared server?
You're doing it correctly.
When I deployed another site with php (using CodeIgniter) I had to do nothing
Certainly an unfair comparison. Apparently, they already installed PHP and the database for you. Nice of them.
Also, PHP is not Python. PHP is a plug-in to Apache. Python is "just" a programming language, that requires a separate plug-in to Apache (i.e., mod_python or mod_wsgi).
See How nicely does Python 'flow' with HTML as compared to PHP?
Django hosting support is not as widespread as for PHP, but there are some good options. I can recommend WebFaction - they provide an easy-to-use control panel which offers various combinations of Django versions, Python versions, mod_python, mod_wsgi, MySQL, PostgreSQL etc. They're cost-effective, too. If you use their setup, you get SSH access but just about all of the setting up can be done via their control panel, apart from the actual uploading of your project folder.
Disclaimer: apart from being a happy customer I have no other connection with them.
You didn't have to do anything when deploying a PHP site because your hosting provider had already installed it. Web hosts which support Django typically install and configure it for you.
You just install this already made solution if your allowed to run an image on a virtual machine. I can imagine installations will be done this way in future as complicated security configuration can be done automatically.
Most shared hosting sites run the LAMP (Linux, Apache, MySQL, PHP) stack so deployment is just a matter of copying some files over. If you were using one of the PHP frameworks like CakePHP or something the service hasn't installed (like an imaging library) you'd be going through extra deployment steps as well.
With Django (or Rails, or any other complex framework) you have to set up the stack yourself that one time, then you're good to go.
However, you'll also want to think about post-deployment updating. If it's something you're going to do often you may also want to look into Fabric or Capistrano to help automate that.
P.S. I'll second that WebFaction recommendation. It's as close to one-button installation as I've seen. Pretty happy customer although I mostly use them for test-sites and prototyping.
You can use Python virtualenv and pip (see also "Tools of the Modern Python Hacker: Virtualenv, Fabric and Pip"). I developed my Django project in the virtual environment. I copy the virtual environment file to the production machine when I deploy my application. I use mod_wsgi. You must write that in the mod_wsig file:
import site
site.addsitedir('C:\PythonVirtualEnv\IntegralEnv\Lib\site-packages')
Good morning.
As the title indicates, I've got some questions about using python for web development.
What is the best setup for a development environment, more specifically, what webserver to use, how to bind python with it. Preferably, I'd like it to be implementable in both, *nix and win environment.
My major concern when I last tried apache + mod_python + CherryPy was having to reload webserver to see the changes. Is it considered normal? For some reason cherrypy's autoreload didn't work at all.
What is the best setup to deploy a working Python app to production and why? I'm now using lighttpd for my PHP web apps, but how would it do for python compared to nginx for example?
Is it worth diving straight with a framework or to roll something simple of my own? I see that Django has got quite a lot of fans, but I'm thinking it would be overkill for my needs, so I've started looking into CherryPy.
How exactly are Python apps served if I have to reload httpd to see the changes? Something like a permanent process spawning child processes, with all the major file includes happening on server start and then just lazy loading needed resources?
Python supports multithreading, do I need to look into using that for a benefit when developing web apps? What would be that benefit and in what situations?
Big thanks!
What is the best setup for a development environment?
Doesn't much matter. We use Django, which runs in Windows and Unix nicely. For production, we use Apache in Red Hat.
Is having to reload webserver to see the changes considered normal?
Yes. Not clear why you'd want anything different. Web application software shouldn't be dynamic. Content yes. Software no.
In Django, we develop without using a web server of any kind on our desktop. The Django "runserver" command reloads the application under most circumstances. For development, this works great. The times when it won't reload are when we've damaged things so badly that the app doesn't properly.
What is the best setup to deploy a working Python app to production and why?
"Best" is undefined in this context. Therefore, please provide some qualification for "nest" (e.g., "fastest", "cheapest", "bluest")
Is it worth diving straight with a framework or to roll something simple of my own?
Don't waste time rolling your own. We use Django because of the built-in admin page that we don't have to write or maintain. Saves mountains of work.
How exactly are Python apps served if I have to reload httpd to see the changes?
Two methods:
Daemon - mod_wsgi or mod_fastcgi have a Python daemon process to which they connect. Change your software. Restart the daemon.
Embedded - mod_wsgi or mod_python have an embedded mode in which the Python interpreter is inside the mod, inside Apache. You have to restart httpd to restart that embedded interpreter.
Do I need to look into using multi-threaded?
Yes and no. Yes you do need to be aware of this. No, you don't need to do very much. Apache and mod_wsgi and Django should handle this for you.
So here are my thoughts about it:
I am using Python Paste for developing my app and eventually also running it (or any other python web server). I am usually not using mod_python or mod_wsgi as it makes development setup more complex.
I am using zc.buildout for managing my development environment and all dependencies together with virtualenv. This gives me an isolated sandbox which does not interfere with any Python modules installed system wide.
For deployment I am also using buildout/virtualenv, eventually with a different buildout.cfg. I am also using Paste Deploy and it's configuration mechanism where I have different config files for development and deployment.
As I am usually running paste/cherrypy etc. standalone I am using Apache, NGINX or maybe just a Varnish alone in front of it. It depends on what configuration options you need. E.g. if no virtual hosting, rewrite rules etc. are needed, then I don't need a full featured web server in front. When using a web server I usually use ProxyPass or some more complex rewriting using mod_rewrite.
The Python web framework I use at the moment is repoze.bfg right now btw.
As for your questions about reloading I know about these problems when running it with e.g. mod_python but when using a standalone "paster serve ... -reload" etc. it so far works really well. repoze.bfg additionally has some setting for automatically reloading templates when they change. If the framework you use has that should be documented.
As for multithreading that's usually used then inside the python web server. As CherryPy supports this I guess you don't have to worry about that, it should be used automatically. You should just eventually make some benchmarks to find out under what number of threads your application performs the best.
Hope that helps.
+1 to MrTopf's answer, but I'll add some additional opinions.
Webserver
Apache is the webserver that will give you the most configurability. Avoid mod_python because it is basically unsupported. On the other hand, mod_wsgi is very well supported and gives you better stability (in other words, easier to configure for cpu/memory usage to be stable as opposed to spikey and unpredictable).
Another huge benefit, you can configure mod_wsgi to reload your application if the wsgi application script is touched, no need to restart Apache. For development/testing servers you can even configure mod_wsgi to reload when any file in your application is changed. This is so helpful I even run Apache+mod_wsgi on my laptop during development.
Nginx and lighttpd are commonly used for webservers, either by serving Python apps directly through a fastCGI interface (don't bother with any WSGI interfaces on these servers yet) or by using them as a front end in front of Apache. Calls into the app get passed through (by proxy) to Apache+mod_wsgi and then nginx/lighttpd serve the static content directly.
Nginx has the added advantage of being able to serve content directly from memcached if you want to get that sophisticated. I've heard disparaging comments about lighttpd and it does seem to have some development problems, but there are certainly some big companies using it successfully.
Python stack
At the lowest level you can program to WSGI directly for the best performance. There are lots of helpful WSGI modules out there to help you in areas you don't want to develop yourself. At this level you'll probably want to pick third-party WSGI components to do things like URL resolving and HTTP request/response handling. A great request/response component is WebOb.
If you look at Pylons you can see their idea of "best-of-breed" WSGI components and a framework that makes it easier than Django to choose your own components like templating engine.
Django might be overkill but I don't think that's a really good argument against. Django makes the easy stuff easier. When you start to get into very complicated applications is where you really need to look at moving to lower level frameworks.
Look at Google App Engine. From their website:
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infrastructure. App Engine
applications are easy to build, easy
to maintain, and easy to scale as your
traffic and data storage needs grow.
With App Engine, there are no servers
to maintain: You just upload your
application, and it's ready to serve
your users.
You can serve your app using a free
domain name on the appspot.com domain,
or use Google Apps to serve it from
your own domain. You can share your
application with the world, or limit
access to members of your
organization.
App Engine costs nothing to get
started. Sign up for a free account,
and you can develop and publish your
application for the world to see, at
no charge and with no obligation. A
free account can use up to 500MB of
persistent storage and enough CPU and
bandwidth for about 5 million page
views a month.
Best part of all: It includes Python support, including Django. Go to http://code.google.com/appengine/docs/whatisgoogleappengine.html
When you use mod_python on a threaded Apache server (the default on Windows), CherryPy runs in the same process as Apache. In that case, you almost certainly don't want CP to restart the process.
Solution: use mod_rewrite or mod_proxy so that CherryPy runs in its own process. Then you can autoreload to your heart's content. :)