I'm new to Django (in server side programing in general) and I don't know how to declare a state and be able to update it from client side.
What I want to do is be able for some users to set a "maintenance" state (boolean) to true or false.
I'm using Django Rest Framework.
Can someone give me a clue or documentation to read?
Thanks
Based on the comments under your question I assume we're discussing a maintenance mode of the whole service.
This would usually be done by the service infront of your application, i.e. nginx, which you need for other things as well.
But since you need the site admins to be able to trigger it you could store that value in a cache service.
One of them would be Redis which works nicely with Django's cache framework. You could make a custom middleware that would check for that maintenance value in Redis and throw the maintenance page.
A middleware would be optimal as it will ensure the whole service (all URLs) are kept hidden if maintenance mode is on.
Related
everyone! I am building a web application, i.e. a server-client application. For the interaction between the two, I have to define the URLs twice (hard-coded strings), both on the backend and the frontend, which makes future changes hard, because it would require changing the code in two places, rather than just one.
I am using Django and Angular and so I am looking for a way to specify the back end endpoints once, then ideally read them and use them for the Angular production build. Therefore changes to the endpoints will only require a new build, but no further changes.
Should these be defined in some .cfg file and be read by the back end on server startup and maybe somehow add them to the Angular's build process? Any suggestion would help because this redundancy comes in almost every webapp project and there has to be a more clever solution!
Thanks for the help in advance!
Here, it is the backend application that owns and defines url mappings to entities. It is possible that multiple clients can consume from the same API, like a web client, an Android client and an iOS client. In this setup, your backend is the point of truth for the url mappings, and client applications should be configured to use the url mappings defined in the backend application.
One possible way to do this is to serve defined urls in the backend on a path of the backend application, and have your client applications configure themselves using the data provided there. For example, if you use Django Rest Framework, by default, on the root path of the API ("/"), resources along with url mappings for the resources are served. You can use such a mechanism to configure your client applications on build time.
How many endpoints and how likely are you to alter them? Most likely you will always have to make more changes than just in 1 place as the reason behind changing an endpoint is normally you are trying to POST or GET new data structures. This would mean you will have to alter that request process anyway to handle the new data type or what was being posted.
Also, consider some of the publicly available api's out there - they don't give you an endpoint that serves a config file of available routes. When they make a change to their endpoints they usually create a versioned api so that consumers can upgrade in their own time.
In my opinion, unless you are planning a large scale web app, I wouldn't be too worried about trying to implement something like this.
I'm currently working on a project which would require some realtime functionalities such as Multi-user chatrooms etc.
Ideally, I’m looking to have meteor run the chat application(on a different port) and mongodb act as message broker to the django back-end which would take care of user registration , management and everything 'non-realtime' related.
This would involve setting up a reverse-proxy which would redirect to a different port based on the url (please let me know if i'm wrong in this)
Would this be possible(or even advisable)? Another option would be to implement the same with tornado. but I have no experience with building tornado-based apps and rather do this with a framework I’m comfortable with.
Thanks,
You can have Django serve the Meteor front-end while providing access to its data using django-ddp, giving you some distinct advantages:
Continue to serve your existing Django project/apps.
No extra services or ports to manage.
Scale out by simply adding more front-end Python/Django servers (server to server IPC is done via the existing database connection).
Use django.contrib.auth user accounts in your Meteor app.
Familiar Python/Django code (no "callback" style such as with Tornado).
Use time-tested, trusted relational databases.
Use Django migrations to effectively manage schema changes.
There's a Gitter chat room where I can give you assistance if you need it.
DISCLAIMER: I'm the author of django-ddp.
A meteor application is more than capable of handling the user registration flow and many other things. Why not just build the application entirely in meteor? Your application sounds like a perfect candidate for meteor, with realtime interaction with your database at the core.
The other option would be to use swampdragon which adds realtime data binding within django. It allows for simple bi directional communication between the server and the client. Again, essential for a chat application. It nice and easy to get setup and running as well.
Are there any specific reasons to not implementing your application in one framework alone?
I have an Django application at my work, only available on the internal network.
Currently we import data using Excel, but this is a terrible error prone process and I want to replace it.
I would like to provide a rich web application in Javascript which exposes some, but not all of the data from the main Django application (lookup values for menus). This would run on a server visible to the outside world.
So what is a good approach for this?
Management are concerned about security of making the main Django app available to the outside world, and I would prefer an intermediate tier as well - I think it would be easier to write a small server side app than to go through the current code and make sure it is secure enough to the outside world (I learned Django buildiong this app, so some of the older code is not done according to best practices, but does work as it needs to). I would also like it to hold the new data until someone has checked it looks OK before importing to the main database. (I am the only developer, so there are time considerations).
So two options I can think of just now.
1: Have a small Django app on an external facing server. This can communicate with the main app to get the values required for lookups, and store the input before it gets imported. The tables will essentially mirror the main app and need updated when the main app tables change.
2: Have something similar, but rather than use a database, use the external facing server to contact the REST interface on the internal server. Something like using Django non-relational to get data from the REST interface of the main app. Put an import table in the main database server to store the dats for approval.
Are either of these good / bad approaches?
Any other suggestions?
Are there any good resources for learning about n-tier apps?
If I understand you correctly you want a small Group of trusted users to be able to access an internal database. There is already an Internal Django App accessing that database.
Management is concerned about making this app or an extension of it available to the general Internet.
I think ther concerns are very valid. If you have only a limited set of users accessing the import functionality, push authentication out of the Django Web Application into the HTTP Server / Balancer / Frontend.
For example set up an apache external webserver forcing all access to your Django App beeing encrypted (HTTPS) and authenticated. Users can be authenticated via HTTP-Auth using static files on the server. Password changes / user additions have to be done by an admin logging into the server.
Only after completing this login the Django App with it's own authentication can be accessed. I would opt vor a smale seperate import App instead of extending the main app. This small app could run with reduced permissions on the main database for an defense in depth aproach.
This setup provides you with a litte additional interfaces / points of failures, while maintaining a small attack surface against random Internet users. You can hire a security consultant th audit your apache config and be assured that you locked out the greater Internet and only have to worry about HTTP-Authenticated users.
I have benn running such setups for 15 years by now. Users are annoyed by the double authentication and password saving in Internet Cafes is an issue whith HTTP-Auth but generally it is verry seamless if once set up.
I am working a real-time lighting control system.
User can turn on/off lights through web interface, but when another person turn on/off light switch manually the web interface should be updated immediately. That's the real-time goal I want.
The structure of the system is like this.
I have my own server at home, which control/monitor light status real-time. Django project is on my cloud server communicating with my home server real-time.
I have searched some similar posts and found many tools that confuse me a lot. All I want is to do long polling. User's browser will send http request to django server periodically(say 30s). If nothing comes up, server will hold the response until next one come. If there is an event, server will just reply immediately so real-time change at the browser side.
I know websocket is a better way, but I just want to make it work, the simpler the better. As long as it's reliable, compatible with existing browsers, performance is not a primary concern for me now. I can change it later if there is performance issue when scaling up. If it's possible, I still want to use Apache server to do this.
Does anyone knows a good tutorial or example that shows me how to implement it?
Thanks so much
I use Django 1.4, wsgi, Apache.
I have built a website in django framework. It has a lot of features such as blog, discussion forum, basically there are lots of ways users can interact. I have built a basic notification framework where a user gets notified when somebody comments on their blog, or answers their question in the forum.
Since the notifications are stored in db, new notifications are displayed only when a page refresh is done. I would like to make it real time using some push server using something like long polling technique.
I have come across NowJS which seems to be pretty handy for this, but in all the examples that are given I could not see any example where there was any interaction with the database. In all the cases there was some information sent by one client and it was displayed to one or more clients.
What I actually want to do is to call a function using NowJS, and make it go to sleep until a new notification is added in the database. When a new notifications comes in the server responds back with the notification and a new request is done immediately.
I can figure out all other parts except how to access the database from Node server that is used by NowJS. Any help or guidance is appreciated.
Either:
Have your node.js server make an http call to the Django server via something like a REST api to get info back
Google for a database connector for node.js - I found enough evidence for a MySQL one, and rumours of a PostgreSQL one. Note this won't get you access to the Django DB API, so you'll have to work out all your related queries and craft your SQL by hand (make sure Bobby Tables doesn't bother you: http://www.xkcd.com/327)
Re-implement the NowJS protocol so that you can write a django server for it, keeping the same JS client code on the clients... but then you may as wel.....
...use django-socketio http://blog.jupo.org/2011/08/13/real-time-web-apps-with-django-and-websockets/