I use a bot that writes (file ids) of the files that sent from user to a text file and then read from this text file the (file ids) then send it back to the user.The method worked, but when I deploy it to Heroku, I can no longer see, process, or download the text file.
Is there a way to view the text files that we deploy to heroku? Or is there a way to upload the text files on a cloud website and then make the bot open (read & write) the text file using the text file URL (but I think this would allow any user on the internet to access and modify my text files, which means it is not safe)? Create SQL database and upload text files and link each text file with its own URL (But I'm new to SQL)?
Is there any other simple method to solve this problem? What do you advise me to do in this case?
https://github.com/zieadshabkalieh/a
NOTE: The text file in my code named first.txt
Heroku has an ephemeral filesystem: every file created by the application will be removed (also any change to existing files deployed with the application) when there is a new deployment or application restart.
Heroku Dynos also restart every 24 hours.
It is a good idea to persist data to a remote storage (like S3) or a DB (always a good option but requires a little bit more work).
For reading/writing simple files you can check HerokuFiles repository with some Python examples and options. I would suggest S3 (using Python boto module) as it is easy to use, even if the number/size of files will one day increase.
I have a website (managed with python-flask) with images on canvas and i would like to pass the content of those canvas to another python script as images.
The other python script is using openCV in order to perform face detection.
I know i could upload the image on my server and then read the file on my opencv application but i would like not to save any data on my server.
Do you have any ideas ?
You anyway should upload file to the server, because you need to transfer user's data to your server application.
But instead of saving it as a regular file, you could use someting like SpooledTemporaryFile
In other words, you'll have workflow like this:
Send image with POST to the server;
Read file from POST request with flask;
Write it to SpooledTemporaryFile and receive a file-like object;
Use that file-like object for OpenCV
Before I pose the question, some background: I'm creating a web management tool that, among other things, allows the user to download, tail, email, and move and files between predefined directories via the management panel. Many of these directories are local to the server, but some are actually located on remote hosts and accessed via SSH--however, this is transparent to the user. I've used Twisted to create a pseudo-REST API for the client to access, but since I want to avoid revealing actual server paths to the client, it requests downloads of files using a POST with an arbitrary ID to the api, as such: "http://XXXX:8880/api/transfer/download"
with POST params similar to this: {"srckey":"5","srcfile":"solar2-windows-1.10.zip"}. The idea being the client only knows the key of the directory and filename.
Pardon the excessive background--I'm hoping it will make my question more clear: The issue I have is I'm trying to allow users to download a copy of a file from one of the "remote" hosts via the management server that hosts the web panel, all without caching the file locally. I've used Twisted's File() object to stream large static files before, but since the file resides on another server, I'm trying to accomplish the same using a file object provided by Paramiko's "open()" method.
I've tried setting up a consumer/producer system similar to that used in the render methods of twisted.web.static.File, plugging in the file pointer provided by Paramiko in the appropriate places, but only the smallest text files transfer successfully--all cases cause Paramiko to throw this error:
socket.error: Socket is closed
The contents of the relevant python files are here:
serve-project.py: http://pastebin.com/YcjsQHu3
WrapSSH.py:
http://pastebin.com/XaKXJwxb
In a nutshell, I'm trying to stream the data from a Paramiko SFTPFile to an HTTP client. I suspect that my approach is majorly faulty, due to my minimal familiarity with Twisted. Anyone have suggestions on a more intelligent way to accomplish this?
Im writing simple blogging platform in Flask microframework, and I'd like to allow users to change image on the front page but without actually writing it into filesystem. Is it possible to point src attribute in img tag to an object stored in memory?
Yes, you can do it.
Create a controller or serlvet called for example
www.yoursite.com/getImage/ID
When you execute this URL, your
program shoud connect to the memcached and return the image object
that you have previously stored in it.
Finally when in your html you add: src="www.yoursite.com/getImage/ID" the browser will execute
this url, but instead of reading a file from disk it will ask the memcached for the specific ID.
Be sure to add the correct content-type in your response from the server in order that the browser understand that you are sending an image content.
Fer
I am using this file storage engine to store files to Amazon S3 when they are uploaded:
http://code.welldev.org/django-storages/wiki/Home
It takes quite a long time to upload because the file must first be uploaded from client to web server, and then web server to Amazon S3 before a response is returned to the client.
I would like to make the process of sending the file to S3 asynchronous, so the response can be returned to the user much faster. What is the best way to do this with the file storage engine?
Thanks for your advice!
I've taken another approach to this problem.
My models have 2 file fields, one uses the standard file storage backend and the other one uses the s3 file storage backend. When the user uploads a file it get's stored localy.
I have a management command in my application that uploads all the localy stored files to s3 and updates the models.
So when a request comes for the file I check to see if the model object uses the s3 storage field, if so I send a redirect to the correct url on s3, if not I send a redirect so that nginx can serve the file from disk.
This management command can ofcourse be triggered by any event a cronjob or whatever.
It's possible to have your users upload files directly to S3 from their browser using a special form (with an encrypted policy document in a hidden field). They will be redirected back to your application once the upload completes.
More information here: http://developer.amazonwebservices.com/connect/entry.jspa?externalID=1434
There is an app for that :-)
https://github.com/jezdez/django-queued-storage
It does exactly what you need - and much more, because you can set any "local" storage and any "remote" storage. This app will store your file in fast "local" storage (for example MogileFS storage) and then using Celery (django-celery), will attempt asynchronous uploading to the "remote" storage.
Few remarks:
The tricky thing is - you can setup it to copy&upload, or to upload&delete strategy, that will delete local file once it is uploaded.
Second tricky thing - it will serve file from "local" storage until it is not uploaded.
It also can be configured to make number of retries on uploads failures.
Installation & usage is also very simple and straightforward:
pip install django-queued-storage
append to INSTALLED_APPS:
INSTALLED_APPS += ('queued_storage',)
in models.py:
from queued_storage.backends import QueuedStorage
queued_s3storage = QueuedStorage(
'django.core.files.storage.FileSystemStorage',
'storages.backends.s3boto.S3BotoStorage', task='queued_storage.tasks.TransferAndDelete')
class MyModel(models.Model):
my_file = models.FileField(upload_to='files', storage=queued_s3storage)
You could decouple the process:
the user selects file to upload and sends it to your server. After this he sees a page "Thank you for uploading foofile.txt, it is now stored in our storage backend"
When the users has uploaded the file it is stored temporary directory on your server and, if needed, some metadata is stored in your database.
A background process on your server then uploads the file to S3. This would only possible if you have full access to your server so you can create some kind of "deamon" to to this (or simply use a cronjob).*
The page that is displayed polls asynchronously and displays some kind of progress bar to the user (or s simple "please wait" Message. This would only be needed if the user should be able to "use" (put it in a message, or something like that) it directly after uploading.
[*: In case you have only a shared hosting you could possibly build some solution which uses an hidden Iframe in the users browser to start a script which then uploads the file to S3]
You can directly upload media to the s3 server without using your web application server.
See the following references:
Amazon API Reference : http://docs.amazonwebservices.com/AmazonS3/latest/dev/index.html?UsingHTTPPOST.html
A django implementation : https://github.com/sbc/django-uploadify-s3
As some of the answers here suggest uploading directly to S3, here's a Django S3 Mixin using plupload:
https://github.com/burgalon/plupload-s3mixin
I encountered the same issue with uploaded images. You cannot pass along files to a Celery worker because Celery needs to be able to pickle the arguments to a task. My solution was to deconstruct the image data into a string and get all other info from the file, passing this data and info to the task, where I reconstructed the image. After that you can save it, which will send it to your storage backend (such as S3). If you want to associate the image with a model, just pass along the id of the instance to the task and retrieve it there, bind the image to the instance and save the instance.
When a file has been uploaded via a form, it is available in your view as a UploadedFile file-like object. You can get it directly out of request.FILES, or better first bind it to your form, run is_valid and retrieve the file-like object from form.cleaned_data. At that point at least you know it is the kind of file you want it to be. After that you can get the data using read(), and get the other info using other methods/attributes. See https://docs.djangoproject.com/en/1.4/topics/http/file-uploads/
I actually ended up writing and distributing a little package to save an image asyncly. Have a look at https://github.com/gterzian/django_async Right it's just for images and you could fork it and add functionalities for your situation. I'm using it with https://github.com/duointeractive/django-athumb and S3