nginx gives 502 error with uwsgi for running django on ubuntu 18.04 LTS

Question

Note: I am new to django and its deployment.

Deployed django through uwsgi and nginx according to the steps mentioned in this guide - except the emperor-vassal configuration and without any virtual environment.

Side note: The site comes up using python3 manage.py 0.0.0.0:8800

But, it seems that nginx is facing permission issues in the socket and giving a 502 bad gateway error in the browser.

The nginx error log shows the following error:

2020/07/08 21:05:40 [crit] 3943#3943: *3 connect() to unix:///home/ubuntu/deploymenttst/MySite/MySite.sock failed (13: Permission denied) while connecting to upstream, client: 192.168.12.12, server: 192.168.12.12, request: "GET / HTTP/1.1", upstream: "uwsgi://unix:///home/ubuntu/deploymenttst/MySite/MySite.sock:", host: "192.168.12.12:8400"

The configuration are as follows:

1. In settings.py file of the project, the configuration are set as (apart from the default wsgi):

    DEBUG = False ALLOWED_HOSTS = [ "192.168.12.12" ] STATIC_URL = '/static/' STATICFILES_DIRS = ( os.path.join(BASE_DIR, 'static'), ) STATIC_ROOT = os.path.join(BASE_DIR, 'staticfiles')

2. The MySite_nginx.conf file inside /etc/nginx/sites-available/MySite_nginx.conf has the following configuration entries:

    # MySite_nginx.conf # the upstream component nginx needs to connect to upstream django { server unix:///home/ubuntu/deploymenttst/MySite/MySite.sock; # for a file socket #server 127.0.0.1:8008; } # configuration of the server server { # the port your site will be served on listen 8400; # the domain name it will serve for server_name 192.168.12.12; # substitute your machine's IP address or FQDN charset utf-8; # max upload size client_max_body_size 75M; # adjust to taste # # Django media location /media { alias /home/ubuntu/deploymenttst/MySite/media; # your Django project's media files - amend as required } location /static { #alias /home/ubuntu/deploymenttst/MySite/main/static; # your Django project's static files - amend as required #alias /home/ubuntu/deploymenttst/MySite/register/static; # your Django project's static files - amend as required alias /home/ubuntu/deploymenttst/MySite/static; # your Django project's static files - amend as required } # Finally, send all non-media requests to the Django server. location / { uwsgi_pass django; include /home/ubuntu/deploymenttst/MySite/uwsgi_params; # the uwsgi_params file you installed } }

   It has been sym linked to /etc/nginx/sites-enabled/MySite_nginx.conf.

3. The uwsgi_params file is made inside the project directory containing the following entries:

    uwsgi_param QUERY_STRING $query_string; uwsgi_param REQUEST_METHOD $request_method; uwsgi_param CONTENT_TYPE $content_type; uwsgi_param CONTENT_LENGTH $content_length; uwsgi_param REQUEST_URI $request_uri; uwsgi_param PATH_INFO $document_uri; uwsgi_param DOCUMENT_ROOT $document_root; uwsgi_param SERVER_PROTOCOL $server_protocol; uwsgi_param REQUEST_SCHEME $scheme; uwsgi_param HTTPS $https if_not_empty; uwsgi_param REMOTE_ADDR $remote_addr; uwsgi_param REMOTE_PORT $remote_port; uwsgi_param SERVER_PORT $server_port; uwsgi_param SERVER_NAME $server_name;

4. The content inside the MySite_uwsgi.ini file is as follows:

    [uwsgi] # Django-related settings # the base directory (full path) chdir = /home/ubuntu/deploymenttst/MySite # Django's wsgi file module = MySite.wsgi # the virtualenv (full path) #home = /home/ubuntu/deploymenttst/MySite/ # process-related settings # master master = true # maximum number of worker processes processes = 20 # the socket (use the full path to be safe socket = /home/ubuntu/deploymenttst/MySite/MySite.sock #... with appropriate permissions - may be needed chmod-socket = 666 uid = www-data gid = www-data # clear environment on exit vacuum = true

5. Static files have been collected inside a static directory inside the project directory using python3 manage.py collectstatic

6. In one of the terminal windows, the uwsgi process is started successfully using: uwsgi --ini MySite_uwsgi.ini

7. nginx has been stopped and started and restarted multiple time upon each configuration change and otherwise as well.

8. The uid:gid of the MySite project directory has been set to www-data:www:data using sudo chown -R www-data:www:data *

Why am I still getting that bad gateway 502 error wherein upstream django application cannot be contacted due to permission issues?

Answer 1

Solved the issue by placing the project to /tmp directory.

nginx being run from www-data user was not able to access the internal directory MySite and thus the socket or the files placed there, despite being assigned to the user www-data.

Now, my other question is regarding the cause of permission issue for nginx, despite providing the the uid and gid of the directory to www-data, what could have been the issue?

Note: My user named ubuntu is a sudoer.