Can a Django app be run directly from python? - python

I have created an app with Django, on my Raspberry Pi, as part of my smart home project. Now that I am coming to the end of the project, I would like to make it so that I can run one script and have all of the features of the smart home working. (This would be especially useful as then I can just make it run on boot without having to connect a screen or ssh).
What I would like to know is if there is a way I can make a python script that will run the whole Django app so that I don't have to go into terminal and set it up. Is this possible? and if not what is the best way to go about my issue?

Yes you can do that you set the autologin in raspi-config then create a shell script run.sh
like this
python /path/to/project.manage.py runserver 0.0.0.0:8000
or you can use gunicorn proxy
You can also start other servers in this file
then put sh run.sh in you .bashrc.
Better way
You can install tmux by apt-get install tmux
You can make detached session using tmux in run.sh using a unique name and tmux so that each time you open the prompt it wont create duplicate sessions.

Related

systemd service not executing notify-send

I want to generate pop-ups for certain events in my python script. I am using 'notify-send' for that purpose.
subprocess.Popen(['notify-send', "Authentication", "True/False"])
The above command executes fine on terminal but when I run it from systemd-service it does not generate any pop-up.
When I see logs there are no errors.
You need to first set the environment variable so that the root can communicate with the currently logged user and send the notification in GUI.
In my case, I did it as follow:
[Unit]
Description=< write your description>
After=systemd-user-sessions.service,systemd-journald.service
[Service]
Type=simple
ExecStart=/bin/bash /<path to your script file>.sh
Restart=always
RestartSec=1
KillMode=process
IgnoreSIGPIPE=no
RemainAfterExit=yes
Environment="DISPLAY=:0" "XAUTHORITY=/home/<User name>/.Xauthority"
[Install]
WantedBy=multi-user.target
Here,
RemainAfterExit=yes
is very important to mention in service file.
make sure to change all the parameters like Description, User name and path to your script file.
also, make sure that script file has executable permission by executing the command
sudo chmod +x <path to your script file>.sh
Here my script file is written in bash which shows the notification by using the same 'notify-send' command.
Now here the Environment parameter is doing all the magic.
you can read more about this behavior and the problem discussed overhere.
I certainly don't know the complete working of these files or how this worked, but for me, it worked just fine.
So you can give it a try.
please let me know if this worked or not in your case.
Running graphical applications requires the DISPLAY environment variable to be set, which would be set when run it from the CLI, but not when run from systemd (unless you explicitly set it).
This issue is covered more in Writing a systemd service that depends on XOrg.
I agree with the general advise that systemd may not be the best tool for the job. You may be better off using an "auto start" feature of your desktop environment to run your app, which would set the correct things in the environment that you need.
If running notify-send for desktop notifications in cron, notify-send is sending values to dbus. So it needs to tell dbus to connect to the right bus. The address can be found by examining DBUS_SESSION_BUS_ADDRESS environment variable and setting it to the same value.
Copy the value of DISPLAY and DBUS_SESSION_BUS_ADDRESS from your running environment and set them in [Service].Environment section
More info on the Arch Wiki:
https://wiki.archlinux.org/index.php/Cron#Running_X.org_server-based_applications

Run python script right after RPi boot

I'm relatively new to raspberry pi (5 days using it) and I've just finished to run my python script succesfully (called dogcare.py). Now I'm trying to execute this script right after my raspberry is turned on. I've been doing some research and I find different ways to do it:
using /etc/profile
using /etc/rc.local
using crontab
using /etc/init.d
using systemd
But none of these ways are working for me.
Setup enviroment:
Hardware: RaspberryPi 2 Model B
Software: Raspbian or NOOBs (not sure)
Context:
Since for my project I need to run meet.jit.si, I followed this guide http://www.instructables.com/id/Video-Calling-on-Raspberry-Pi-3/?ALLSTEPS and It has a step where sets chromium website to start right after RPi is turned on. (Currently this is working fine)
My python script is using request library in order to use HTTP GET with an external website application I've been working on.
Main problem:
I need to run both events: chromium website with meet.jit.si and my python script when my raspberry is turned on.
Current situation: chromium website is running after my RPi is turned on but my script doesn't.
I'd appreciate any help !
I have done a similar thing with my Raspi 2 as well which involved sending myself an email with the ip address of the pi so I could easily ssh/vnc to it.
My steps involved making a shell script which ran the python program.
#!/bin/sh
cd pythonfiledirectory
sudo python pythonfile.py
cd /
Then I made it executable with the following command:
chmod 777 file.sh
Now edit your crontab to run the file on startup.
In your terminal, type:
sudo crontab -e
Inside of the crontab write:
#reboot sh file.sh
You could add a log file if you wanted to debug and see why it's not working by making a log directory and changing the text you wrote in the crontab to:
#reboot sh file.sh >/logdirectoy/ 2>&1
This is what made it work for me and if it doesn't work try and make sure you can run your .sh file and try the crontab with some other files to debug the problem.

How to login inside a AWS server & do some maintenance on it using Python?

I need to login inside a AWS Linux server, then create a folder, add some ownership on it and lastly restart tomcat.
I know that I should be using Ansible or any config mgmt tool & that's easy way.. but out of curiosity I want to do it using Python.
So basically, the steps that need to be followed are:
Login to Machine
mkdir /mnt/some_new_folder
Give permissions, chown tomcat7:tomcat7 /mnt/some_new_folder
Lastly restart tomcat: sudo service tomcat7 restart
Lastly logout
Is it possible to do all this via Python script ?
With open source tools like Python everything is possible. Only your knowledge sets the limit.
I would suggest using sh module which allows easy execution of remote commands over SSH.
sh + SSH tutorial.
You can use it like:
import sh
print(sh.ssh("username#example.com", "mkdir /foo/bar"))
First you need to setup proper SSH keys and SSH agent.

Start couchpotato.py at boot, without needing to leave ssh session open. ReadyNAS (Debian 7)

I need this command to run automatically on boot or when told to. At the moment i need to run the command in SSH and leave the session open, otherwise it stops.
python CouchPotatoServer/CouchPotato.py
This is on a ReadyNAS (Debian 7)
One easy way to do this would be to create it as a service. Take a look in /etc/init.d and you will find scripts that run as services. Copy one and modify it so that it calls your python script. An good example could be the init script used for starting the avahi daemon. Now, you can use 'service couchPotato start/stop/status', etc. It will also start the service automatically at boot time if the server ever reboots. Find a simple file to use as your template and google init scripts for further assistance. Good luck.
From this page:
To run on boot copy the init script. sudo cp CouchPotatoServer/init/ubuntu /etc/init.d/couchpotato
Change the paths inside the init script. sudo nano /etc/init.d/couchpotato
Make it executable. sudo chmod +x /etc/init.d/couchpotato
Add it to defaults. sudo update-rc.d couchpotato defaults
CouchPotatoServer/init/ubuntu can be found here
sudo update-rc.d <service> <runlevels> is the official Debian way of inserting a service at startup. Its manpage can be read there.
my 2 cents,
Use chkconfig to add the service and specify the run level. Google will give you all you need for examples of how to do this. Good luck.

How do I run Django as a service?

I am having difficulty running Django on my Ubuntu server. I am able to run Django but I don't know how to run it as a service.
Distributor ID: Ubuntu
Description: Ubuntu 10.10
Release: 10.10
Codename: maverick
Here is what I am doing:
I log onto my Ubuntu server
Start my Django process: sudo ./manage.py runserver 0.0.0.0:80 &
Test: Traffic passes and the app displays the right page.
Now I close my terminal window and it all stops. I think I need to run it as a service somehow, but I can't figure out how to do that.
How do I keep my Django process running on port 80 even when I'm not logged in?
Also, I get that I should be linking it through Apache, but I'm not ready for that yet.
Don't use manage.py runserver to run your server on port 80. Not even for development. If you need that for your development environment, it's still better to redirect traffic from 8000 to 80 through iptables than running your django application as root.
In django documentation (or in other answers to this post) you can find out how to run it with a real webserver.
If, for any other reason you need a process to keep running in background after you close your terminal, you can't just run the process with & because it will be run in background but keep your session's session id, and will be closed when the session leader (your terminal) is terminated.
You can circunvent this behaviour by running the process through the setsid utility. See your manpage for setsid for more details.
Anyway, if after reading other comments, you still want to use the process with manage.py, just add "nohup" before your command line:
sudo nohup /home/ubuntu/django_projects/myproject/manage.py runserver 0.0.0.0:80 &
For this kind of job, since you're on Ubuntu, you should use the awesome Ubuntu upstart.
Just specify a file, e.g. django-fcgi, in case you're going to deploy Django with FastCGI:
/etc/init/django-fcgi.conf
and put the required upstart syntax instructions.
Then you can you would be able to start and stop your runserver command simply with:
start runserver
and
stop runserver
Examples of managing the deployment of Django processes with Upstart: here and here. I found those two links helpful when setting up this deployment structure myself.
The problem is that & runs a program in the background but does not separate it from the spawning process. However, an additional issue is that you are running the development server, which is only for testing purposes and should not be used for a production environment.
Use gunicorn or apache with mod_wsgi. Documentation for django and these projects should make it explicit how to serve it properly.
If you just want a really quick-and-dirty way to run your django dev server on port 80 and leave it there -- which is not something I recommend -- you could potentially run it in a screen. screen will create a terminal that will not close even if you close your connection. You can even run it in the foreground of a screen terminal and disconnect, leaving it to run until reboot.
If you are using virtualenv,the sudo command will execute the manage.py runserver command outside of the virtual enviorment context, and you'll get all kind of errors.
To fix that, I did the following:
while working on the virtual env type:
which python
outputs: /home/oleg/.virtualenvs/openmuni/bin/python
then type:
sudo !!
outputs: /usr/bin/python
Then all what's left to do is create a symbolic link between the global python and the python at the virtualenv that you currently use, and would like to run on 0.0.0.0:80
first move the global python folder to a backup location:
mv /usr/bin/python /usr/bin/python.old
/usr/bin/python
that should do it:
ln -s /usr/bin/python /home/oleg/.virtualenvs/openmuni/bin/python
that's it! now you can run sudo python manage.py runserver 0.0.0.0:80 in virtaulenv context!
Keep in mind that if you are using postgres DB on your developement local setup, you'll probably need a root role.
Credit to #ydaniv

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