I have a Linux web application which installs a webserver, a database, digital certificates etc using a set of .sh scripts.
In order to simplify user interaction during installation such as entering passwords, certificate details and such, I want to create a GUI installer. After much deliberation, following are some decisions and related questions
The target systems may or may not have a Desktop or a monitor installed. So providing a web interface to the install process may be the way to go. User would copy the application to the target machine, start the webservice which would then expose a web interface to continue the install. Would Python be a good choice for this?
Since this is an installer itself, the requirements to run it must be practically nil. This requires
Use python's built in SimpleHTTPServer. This will be used the one time during installation and then be killed. Any caveats to using the default python web server?
Compile app into standalone binary using one of the Freezing utilities. We don't want to depend on the user having python on their system and have been asked to account for admins who've removed python due to whatever reason. Is this precaution necessary?
Any comments on the general approach or alternative options will be greatly appreciated.
Related
Background:
I am still new to Python so apologies if this is a naive question. I was originally looking to develop a tool for Windows with a GUI, however, reading around I get the impression that it may be simpler to have my compiled python code somehow 'wrapped' in simpleHTTPServer so users can interact via localhost (much like Jupyter notebook/labs).
Question:
Is there a standard/recommended way to have a compiled python program interface with the user via a localhost port in their web browser? I assume this is a fairly common approach and that a package may already even exist but I've not been able to find anything that gives guidance on how to tackle it.
Alternatively, is is feasible to somehow compile a Django development project to run on localhost?
Ideally, I want an executable file that users can run and their browser opens up at the localhost port required.
If you wish to quickly make a GUI based Python tool, you should consider using Django, a very straightforward framework for WebApps. It is very quick to learn and implement, and you shall very easily be able to integrate highly advanced functionalities too into your tool with ease.
When it comes to distribution of code, you can convert the entire Django App into a windows exe file for ease of distribution and use. There are many python packages that allow you to port python to windows executable files. I would recommend using PyInstaller. You may find this link useful: Recipe Executable From Django.
Alternatively, as someone suggested, you may use Docker, but that would be heavier in terms of space utilized, and will require the user to install the same.
Hope this helps!
I have a server which executes Python scripts from a certain directory path. Incidently this path is a check-out from the SVN trunk version of the scripts. However, I get the feeling that this isn't the right way to provide and update scripts for a server.
Do you suggest other approaches? (compile, copy, package, ant etc.)
In the end a web server will execute some Python script with parameters. How do I do the update process?
Also, I have trouble deciding what is best to handle updated versions which only work for new projects on the server. Therefore, if I update the Python scripts, but only newly created web jobs will know how to handle that. I "delivery" to one of many directories which keep track of versions and the server picks the right one?!
EDIT: I webserver is basically an interface that runs some data analysis. That analysis is the actual scripts that take some parameters and mingle data. I don't really change the web interface. I only need to update the data scripts stored on webserver. Indeed, in some advanced version the web server should also pick the right version of my data scripts. However, at the moment I have no idea which would be the easiest way.
The canonical way of distributing Python code/functionality is by using a PyPi compliant package manager.
A list of available PyPi implementations on python.org:
http://wiki.python.org/moin/PyPiImplementations
Instructions on setting up and using EggBasket:
http://chrisarndt.de/projects/eggbasket/#installation
Instructions on installing ChiShop:
http://justcramer.com/2011/04/04/setting-up-your-own-pypi-server/
Note that for this to work you need to distribute your code as "Eggs"; you can find out how to do this here: http://peak.telecommunity.com/DevCenter/setuptools
A great blog post on the usage of eggs and the different parts in packaging: http://mxm-mad-science.blogspot.com/2008/02/python-eggs-simple-introduction.html
Is it possible to run django without shell access? My hoster supports the following for 5€/month:
python (I assume via mod_python)
mysql
There is no shell nor cronjob support, which costs additional 10€/month, so I'm trying to avoid it.
I know that Google Apps also work without shell access, but I assume that is possible because of their special configuration.
It's possible but not desirable. Having shell access makes it possible to centralise things properly using symlinks.
Get a better host would be my first suggestion. WebFaction is the most recommended shared host for using with Django.
If that's out of your price range, there are plenty of hosts that give you a proper system account (vs just a ftp account) and have mod_python or mod_wsgi (preferred now).
Google Apps works without shell because their system looks for a dispatcher script that you have to write to an exact specification.
It is possible.
Usually you will develop your application locally (where shell access is nice to have) and publish your work to your server. All you need for this is FTP access and some way to import a database dump from your development database (often hosters provide an installation of phpMyAdmin for this).
python (I assume via mod_python)
From my experience, you are most certainly wrong with that assumption. Many low-cost providers claim to support python but in fact provide only an outdated version that can be used with CGI scripts. This setup will have a pretty low performance for Django apps.
I have a Django application that I would like to deploy to the desktop. I have read a little on this and see that one way is to use freeze. I have used this with varying success in the past for Python applications, but am not convinced it is the best approach for a Django application.
My questions are: what are some successful methods you have used for deploying Django applications? Is there a de facto standard method? Have you hit any dead ends? I need a cross platform solution.
I did this a couple years ago for a Django app running as a local daemon. It was launched by Twisted and wrapped by py2app for Mac and py2exe for Windows. There was both a browser as well as an Air front-end hitting it. It worked pretty well for the most part but I didn't get to deploy it out in the wild because the larger project got postponed. It's been a while and I'm a bit rusty on the details, but here are a few tips:
IIRC, the most problematic thing was Python loading C extensions. I had an Intel assembler module written with C "asm" commands that I needed to load to get low-level system data. That took a while to get working across both platforms. If you can, try to avoid C extensions.
You'll definitely need an installer. Most likely the app will end up running in the background, so you'll need to mark it as a Windows service, Unix daemon, or Mac launchd application.
In your installer you'll want to provide a way to locate a free local TCP port. You may have to write a little stub routine that the installer runs or use the installer's built-in scripting facility to find a port that hasn't been taken and save it to a config file. You then load the config file inside your settings.py and whatever front-end you're going to deploy. That's the shared port. Or you could just pick a random number and hope no other service on the desktop steps on your toes :-)
If your front-end and back-end are separate apps then you'll need to design an API for them to talk to each other. Make sure you provide a flag to return the data in both raw and human-readable form. It really helps in debugging.
If you want Django to be able to send notifications to the user, you'll want to integrate with something like Growl or get Python for Windows extensions so you can bring up toaster pop-up notifications.
You'll probably want to stick with SQLite for database in which case you'll want to make sure you use semaphores to tackle multiple requests vying for the database (or any other shared resource). If your app is accessed via a browser users can have multiple windows open and hit the app at the same time. If using a custom front-end (native, Air, etc...) then you can control how many instances are running at a given time so it won't be as much of an issue.
You'll also want some sort of access to local system logging facilities since the app will be running in the background and make sure you trap all your exceptions and route it into the syslog. A big hassle was debugging Windows service startup issues. It would have been impossible without system logging.
Be careful about hardcoded paths if you want to stay cross-platform. You may have to rely on the installer to write a config file entry with the actual installation path which you'll have to load up at startup.
Test actual deployment especially across a variety of firewalls. Some of the desktop firewalls get pretty aggressive about blocking access to network services that accept incoming requests.
That's all I can think of. Hope it helps.
If you want a good solution, you should give up on making it cross platform. Your code should all be portable, but your deployment - almost by definition - needs to be platform-specific.
I would recommend using py2exe on Windows, py2app on MacOS X, and building deb packages for Ubuntu with a .desktop file in the right place in the package for an entry to show up in the user's menu. Unfortunately for the last option there's no convenient 'py2deb' or 'py2xdg', but it's pretty easy to make the relevant text file by hand.
And of course, I'd recommend bundling in Twisted as your web server for making the application easily self-contained :).
I'm writing a web application in Python, intended for use by teachers and pupils in a classroom. It'll run from a hosted website, but I also want people to be able to download a self-contained application they can install locally if they want more performance or they simply won't have an Internet connection available in the classroom.
The users aren't going to be able to manage instructions like "first install Python, then install dependencies, download the .tar.gz archive and type these commands into the command line...". I need to be able to create an all-in-one type installer that can potentially install Python, dependencies (Python-LDAP), some Python code, and register a Python-based web server as a Windows Service.
I've had a look through previous questions, but none quite seem relevant. I'm not concerned about the security of source code (my application will be open source, I'll sell content to go with it), I just need non-technical Windows users to be able to download and use my application with no fuss.
My current thoughts are to use NSIS to create an installer that includes Python and Python-LDAP as MSIs, then registers my own simple Python-based web server as a Windows service and puts a shortcut in the start menu / on the desktop linking to http://localhost. Is this doable with NSIS - can NSIS check for currently installed copies of Python, for instance? Is there a better way of doing this - is there a handy framework available that lets me shove my code in a folder and bundle it up to make an installer?
Using NSIS is great (i use it too) but i would suggest using a "packager" like pyinstaller (my personal fav, alternatives bb_freeze, py2exe) to create an exe before the using NSIS
The primary benefit you get by doing this is;
Your download is smaller as you're not bundling the whole Python Standard Lib and extra stuff your app wont need and you get an exe file to boot!
You can try the Bitnami Stack for Django that includes Apache, MySQL,Python, etc in an all-in-one installer. It is free/open source