Python script as service has not access to asoundrc configuration file - python

I have a python script that records audio from an I2S MEMS microphone, connected to a Raspberry PI 3.
This script runs as supposed to, when accessed from the terminal. The problem appears when i run it as a service in the background.
From what i have seen, the problem is that the script as service, has no access to a software_volume i have configured in asoundrc. The strange thing is that i can see this "device" in the list of devices using the get_device_info_by_index() function.
For audio capturing i use the pyaudio library and for making the script a service i have utilized the supervisor utility.
Any ideas what the problem might be and how i can make my script to have access to asoundrc when it runs as a service?

The ~/.asoundrc file is looked for the home directory of the current user (this is what ~ means).
Put it into the home directory of the user as which the service runs, or put the definitions into the global ALSA configuration file /etc/asound.conf.

Related

Run a script located on remote server using python

I have a python script located on a remote server with SSH enabled. That script displays a lot of debug messages displayed while executing. I want to trigger this script using another python script which is on my local system and depending on the output of the earlier script, I want to proceed further. While doing all this, I want the display messages on the remote server to be displayed on my local system as well. Basically, I want to view whatever output is thrown by the remote script during the course of the script, on my local system. I am able to trigger the script using paramiko but I am neither able to check whether the script on the remote server is running nor am I able to view it's output. Is there any way to do it? Already tried conn.recv(65535) but to no avail.
In my experience I found python fabric module easier than using paramiko. If you want to execute local script on remote machine using fabric. You just need to upload them using put() and then call run() api.
http://docs.fabfile.org/en/1.14/api/core/operations.html#fabric.operations.put

Is it Possible to Run a Python Code Forever?

I have coded a Python Script for Twitter Automation using Tweepy. Now, when i run on my own Linux Machine as python file.py The file runs successfully and it keeps on running because i have specified repeated Tasks inside the Script and I also don't want to stop the script either. But as it is on my Local Machine, the script might get stopped when my Internet Connection is off or at Night. So i couldn't keep running the Script Whole day on my PC..
So is there any way or website or Method where i could deploy my Script and make it Execute forever there ? I have heard about CRON JOBS before in Cpanel which can Help repeated Tasks but here in my case i want to keep running my Script on the Machine till i don't close the script .
Are their any such solutions. Because most of twitter bots i see are running forever, meaning their Script is getting executed somewhere 24x7 . This is what i want to know, How is that Task possible?
As mentioned by Jon and Vincent, it's better to run the code from a cloud service. But either way, I think what you're looking for is what to put into the terminal to run the code even after you close the terminal. This is what worked for me:
nohup python code.py &
You can add a systemd .service file, which can have the added benefit of:
logging (compressed logs at a central place, or over network to a log server)
disallowing access to /tmp and /home-directories
restarting the service if it fails
starting the service at boot
setting capabilities (ref setcap/getcap), disallowing file access if the process only needs network access, for instance

Run executable in Desktop mode with Django / Python on IIS / Windows

The idea:
There is a Node.JS server which sends a request to the IIS server which is running Django / Python. It will send two files to the server which need to be converted with a program which needs to be run in the foreground mode.
So I already looked around in pretty much everything related to IIS and the running of executables here on SO, but still haven't got it working.
I got the following code to run the application from Django:
subprocess.call("C:\example.exe")
There will be probably be some serious security issues (although the server is only reachable from the local network) with the following setup, but here it is:
I'm running a Django application on IIS.
I've set the Application Pool Identity to my local user
I've given "Full Control" permission to "Everyone"
When the subprocess call gets executed it will add the program to my Background Processes with the USER being set to my local user.
Questions:
How do I make the program start in Desktop Mode?
Should I perhaps add another step (start another service) which will then start the program?
Edit:
Could I perhaps make a file watcher which watches if files get stored on the Windows Server and then triggers an executable based on that?

Remote website trigger a local action

I have large video files (~100GB) that are local on my machine. I have a non-local website where I enter information about the video file. In addition, I need to get the checksum of the video file (and I do not want to manually trigger the script locally and copy and paste the value). To get a checksum of the video file, I have a script I can run as $ checksum.py <video file>.
How would I trigger the local script through the web interface? In other words, I want to be able to enter the PATH of the video file and click Submit on the web app, and it will locally trigger the script, and (after the checksum has finished), insert that value into the web app/database. What would be the best way to do this?
You cannot trigger anything unless your local script is continuously listening for some kind of data feed (like a fixed URL serving an XML/JSON feed of paths) which is, IMHO, over-complicating your system.
You could also use a Java applet ran locally instead of a remote website, but you'll have to sign it to be able to read local files, and it might not be what you're looking for.
Think of it: it's all about security. Would you like any web server to trigger scripts in your local machine? I certainly wouldn't.
IMHO the best solution is to trigger the script manually which will send the data to your web server.
In general browsers run in a sandbox that has very limited access to the OS. In particular you can't run shell scripts from a browser. As I see it you have two options:
Adapt your checksum.py script to send the checksum info directly to your website using the urllib2 calls, or pipe the results to a "curl" command. (No browser involved.)
Rewrite checksum.py as JavaScript using the FileReader class. This will probably be convoluted, slow, and won't work in Internet Explorer.

How can I create an local webserver for my python scripts?

I'm looking to use a local webserver to run a series of python scripts for the user. For various unavoidable reasons, the python script must run locally, not on a server. As a result, I'll be using HTML+browser as the UI, which I'm comfortable with, for the front end.
I've been looking, therefore, for a lightweight web server that can execute python scripts, sitting in the background on a machine, ideally as a Windows service. Security and extensibility are not high priorities as it's all running internally on a small network.
Should I run a native python webserver as a Windows service (in which case, how)? Or is it just as easy to install Apache onto the user's machine and run as CGI? Since this is all local, performance is not an issue either.
Or am I missing something obvious?
Don't waste a lot of time creating Windows service.
Don't waste a lot of time on Windows Apache.
Just make a Python service that responds to HTTP requests.
Look at https://docs.python.org/2/library/basehttpserver.html
https://docs.python.org/3/library/http.server.html for version 3
Python offers an HTTP server that you can extend with your server-side methods.
Look at http://docs.python.org/library/wsgiref.html
Python offers a WSGI reference implementation that makes your server easy and standards-compliant.
Also http://fragments.turtlemeat.com/pythonwebserver.php
"I'm trying to avoid making the user run python stuff from the command prompt."
I don't see how clicking a web page is any different from clicking desktop icons.
Starting a web server based on Python is relatively easy, once you have the web server. First, build the server. Later, you can make sure the server starts. Let's look at some ways.
Your user can't use a random browser to open your local page. They need a bookmark to launch "localhost:8000/myspecialserverinsteadofthedestop/" That bookmark can be a .BAT file that (1) runs the server, (2) runs firefox with the proper initial URL.
You can put the server in the user's start-this menu.
You can make your Python program a windows "service".
Best way is to make your own local server by using command prompt.
Make a new folder say Project
Make a new folder inside project & name it as "cgi-bin"(without quotes)
Paste your .py file inside the cgi-bin folder
Open cmd and change to the directory from which you want to run the server and type "python -m CGIHTTPServer"(without quotes)
Minimize the cmd window & open your browser and type "localhost:8000/cgi-bin/yourpythonfilename.py"(without quotes).
The wasiest step would be navigate to folder where your files are located and running http.server module
cd /yourapp
python3 -m http.server
the you should see something like this in console
Serving HTTP on 0.0.0.0 port 8000 (http://0.0.0.0:8000/) ...
Running a native python webserver as a windows service should be a no brainer. Check out the documentation for writing windows services (win32api, ActiveState python) in python and also the documentation for subclassing BaseHttpServer and SimpleHttpServer.
BTW: I had a similar question on stackoverflow: How to stop BaseHTTPServer.serve_forever() in a BaseHTTPRequestHandler subclass?
Basically, you subclass BaseHTTPServer (you have to anyway...) and then... but just read the accepted answer - it set me on the right track!

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