Minimal effort setup of Django for webdesigner - python

In the old world I had a pretty ideal development setup going to work together with a webdesigner. Keep in mind we mostly do small/fast projects, so this is how it worked:
I have a staging site on a server (Webfaction or other)
Designer accesses that site and edits templates and assets to his satisfaction
I SSH in regularly to checkin everything into source control, update files from upstream, resolve conflicts
It works brilliantly because the designer does not need to learn git, python, package tools, syncdb, migrations etc. And there's only the one so we don't have any conflicts on staging either.
Now the problem is in the new world under Heroku, this is not possible. Or is it? In any way, I would like your advice on a development setup that caters to those who are not technical.

How about a static 'showcase' site where all possible UI elements, templates, etc are shown using dummy content. The designer can connect, edit stuff and you merge in the changes in the end. Another option would be a test server with the full application running (kind of like you did it before) but with the option to connect via FTP or whatever the designer prefers.

Why not store all of the assets on S3?
It sounds to me that they don't really need to be part of the application at all, but external resources that the application references.

Related

packaging django application and deploying it locally

I've never worked with Django before so forgive me if a question sounds stupid.
I need to develop a web application, but I do not want to deploy it on a server. I need to package it, so that others would "install" it on their machine and run it. Why I want to do it this way? There are many reasons, which I don't want to go into right now. My question is: can I do it? If yes, then how?
This is possible. However, the client machine would need to be equipped with the correct technologies for this to work.
When you launch a web app on a server (live), the server is required to have certain settings and installs. For example, a Django web app: the server must have a version of Django installed.
Hence, whichever machine is running your web app, must have Django installed. It presumably also needs to have the database too. It might be quite a hassling process but it's possible.
Just like as a developer, you may have multiple users working on 1 project. So, they all need to have that project 'installed' on their devices so they can run it locally.
You need to either use a python to executable program, with Django already in it. The website files you can place into the dist folder or whatever folder has the executable in it. Then you can compress it and share it with others (who have the same OS as you).
For an example:
You have this script in Django (I'm too lazy to actually write one), and you want to share it with someone who doesn't have Python and Django on his/her computer.

Develop whole Zope&Plone app in git (decentralised and without ZMI)

We have few Zope&Plone projects in our company and until today I was only one single developer developing all changes throught ZMI or ZopeEdit. Our company is growing so I need to start cooperating with others developers which can help me with developing features and solving bugs in projects. This means that is no more possible to use ZMI but every developer needs to make and test own changes without affecting others work and paste own changes to production enviroment using git merge in git repo.
I need to move development to git - this means I need to start tracking all portals files and settings in git.
I think I need to move whole projects from ZODB/ZMI (including templates, scripts, sql methods, properties as portal_properties or portal_javascripts etc.) to filesystem and run git on this file system. In the next step every developer can install own pure Plone instance, pull source code and settings from git, create own branch, make changes, test, commit, push, code review ...
My question is: Is there any way to do this and start well-known rapid development process using git? Supports ZODB something like "live migration" of content/settings to/from filesystem? Is there any way to tel Zope to load some folder with content/settings from filesystem instead only from ZODB?
I know there is something called eggs, but is possible to move all types of files mentioned above to separated egg?
Thank you for your help.
The way your company was following until now was the "Old Way Way" of Plone development, but this was a deprecated and discouraged way to do.
Nowadays ZMI can still be used for "quick and dirty" fixes, but commonly this changes stored in DB must be removed (and moved to real code) as soon as possible. This was already possible on Plone 2.0!
More important: every new Plone release tend to reduce the ZMI powers (for example: until Plone 2.1 you were able to do lot of stuff from ZMI, starting from Plone 2.5 some UI elements where impossible to be modified TTW).
So: the answer to your question is "yes". Plone can (must) read code from filesystem, and this code can be stored on VCS (it can be git svn, ...).
All of those information can be found in the Plone Developer Manual.
Creating a new Plone package for modern Plone? Use mr.bob.
Automatically integrate VCS in your buildout? Use mr.developer
If you are starting today from a project you where developing through ZMI you must probably mode code from ZMI to filesystem.
This can be done manually; it's simpler as you are using Zope External Editor.
There is also a very old add-on (Plone Skin Dump) for flushing skin content to filesystem, but I fear it won't work on recent Plone, thus it was not supporting some stuff like SQL methods (if you are using them).
You can have a look at http://docs.plone.org/develop/
There you can find how to create a package (egg). Its source code can be added to git. You can checkout your git repository using mr.developer during buildout. https://pypi.python.org/pypi/mr.developer/
You can use mr.bob to create a PloneAddon. For MySQL you can use MySQL Python. Add this Packages to your Buildout in the eggs section.
Then you can write your own MySQL Statements in the Addon. I know reimplementation is expensive, but you have more control in the future.

Django: Push app from local server to production server via FTP

This is a bit embarassing, but I'm a Django noob and I couldn't find a simple solution to this:
I have written a Django app in a local VM that I now want to deploy to a "production" server. App works like a charm locally.
Now my IT colleague has set up the server with Django and that also works fine. I can open it via the Web and I get the usual "Congratulations on your first Django-powered page". I can also log into the admin interface. The project has been created.
This is a very low-key mini project and I'm not too familiar with git, so we've decided to just push files via FTP. (And I want to stick with that if at all possible.) So I uploaded the app folder into the project folder and also adjusted the project's settings.py and urls.py.
However, nothing seems to be happening on the server's end. The welcome page is the same, the app does not show up in the admin interface and the URLs won't be resolved as hoped.
Any suggestions what I should have done / done differently?
You need to restart apache or whatever is running your django project. Your changes to py files are cached when you first load your server config (settings).
Any suggestions what I should have done / done differently?
You should be using git/jenkins/deployment techniques, I know you said you've decided not to use it but you're going to be missing out on important things like being able to keep track of changes and unit testing

Creating and transferring a site with Django

As a fledgling Django developer, I was wondering if it was customary, or indeed possible, to create a site with Django then transfer the complete file structure to a different machine where it would "go live".
Thanks,
~Caitlin
You could use GIT or Mercurial - or other version control system. To put the site structure on a central server. After that you could deploy the site for example with fabric to multiple servers. For deployment process you should consider using for example virtualenv to isolate the project from global python packages and requirements.
Of course that's possible and in fact it's the only way to "go live". You don't want to develop in your live server, do you? And it's true for any platform, not just django.
If I understood your question correctly, you need a system to push your development code to live.
Use a version control system: git, svn, mercurial etc.
Identify environment specific code like setting/config files etc. and have separate instances of them for each environment.
Create a testing/staging/PP environment which has live data or live-like data and deploy your code there before pushing it to live.
To avoid any downtime during deployment process, usually a symbolic link is created which points to the existing code folder. When a new release is to be pushed, a new folder is created with new code, after all other dependencies are done (like setting and database changes) and the sym link is pointed to the new folder.

Common errors when moving a django app from dev to prod?

I am developping a django app on Windows, SQLite and the django dev server . I have deployed it to my host server which is running Linux, Apache, FastCgi, MySQL.
Unfortunately, I have an error returned by the server on the prod while everything ok on the dev machine. I've asked my provider for a pre-production solution in order to be able to debug and understand the problem.
Anyway, what are according to you the most likely errors that can happen when moving a django app from dev to prod?
Best
Update: I think that a pre-prod is the best way to address this kind of problem. But I would like to build a check list of what must be done before to put in production.
Thanks for the very valuable answers that I received until now :)
Update: FYI, I 've implemented the preprod server and the email notification as suggested by shanyu and I can see that the error comes from the smart_if templatetag that I am using on this new version. Any trick with template tags?
Update: I think I've fixed the pb which was caused I think by the Filezilla FTP sending. I was using the "replace if newer" option which I guess is causing some unexpected results. Using the "replace all" option fix the issue. However, it was an opportunity for me to learn more about deployment. Thansk for your answers.
Problems I typically have include:
Misconfigured productions settings, whether in my production localsettings.py, wsgi/cgi, or apache site files in /etc/sites-available
Database differences. I use South for migrations and have run into some subtle issues when performing my migration on PostgreSQL when it worked smoothly in sqlite.
Static file hosting since I cheat and use the Django server in development
Permissions, both on the file system and within the database
Rare, but possible, network issues preventing me from getting my dependencies, whether on PyPi or some 3rd party site
Ways that I have mitigated these issues:
Use the same database in production and development (in your case, MySQL everywhere)
I've found it is useful to have a "test" environment which mimics production in every way possible (it can be on lower end hardware, or even the same machine). This way, if there are any issues in this "production-like" enivornment, I can solve them without taking my production server offline.
Script everything for repeatable deployments. I use fabric, but zc.buildout or Paver would also work. These tools help reduce typos while deploying and reduce the time to deploy my app.
Use version control (mercurial, git, subversion) and a schema migration tool (like South), so if something does go wrong when you deploy to production, you have the possibility of backing out the changes and allowing production to run on the old code with the old database schema.
I haven't set up an "egg proxy" yet, but I am considering it, to avoid issues when downloading dependencies.
I've found pip's freezing dependencies to be useful, in case a new, incompatible change to a library occurred since I downloaded it initially
Use a web testing framework like Windmill or Selenium to test my application in my "test" environment, so that I can get a lot of test coverage of my system very quickly.
Regarding your case, I can think of 2 simple things that may help you:
You can enable Django to send messages when exceptions occur giving details about them. Look at here for details.
You'll be better off if you set up a test environment on the prod server (say, test.example.com) so that you can check if things will go smoothly or not before you deploy the app.
I believe these were the podcasts I listened to recently (from Pycon 2009):
Locate Django in the Real World (PyCon 2009):
http://advocacy.python.org/podcasts/pycon.rss
Parts 1 to 3
Very good introduction to designing your apps for deployment, in particular for reuse and redeployment.
Regs.

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