"upstream prematurely closed connection while reading response header from upstream" Django, Ubuntu, Nginx, Gunicorn
I deployed a Django website using this tutorial
https://jee-appy.blogspot.com/2017/01/deply-django-with-nginx.html
The website can be accessed from the internet, www.simplesol.com
When I try to make a POST request, it fails and I get a 502 error.
In my nginx-error.log file I get this error message
*344 upstream prematurely closed connection while reading response header
from upstream, client: InternalIP, server: ExternalIP, request: "POST
/audit/ HTTP/1.1", upstream:
"http://unix:/home/webadmin/virtual_env/run/gunicorn.sock:/audit/", host:
"www.simplesol.com", referrer: "http://www.simplesol.com/audit/"
These are the contents of my /etc/nginx/sites-available/simplesol.conf
command = /home/webadmin/gunicorn_start.bash ; Command to start app
user = webadmin ; User to run as
stdout_logfile = /home/webadmin/logs/gunicorn_supervisor.log ; Where to write log messages
redirect_stderr = true ; Save stderr in the same log
environment=LANG=en_US.UTF-8,LC_ALL=en_US.UTF-8 ; Set UTF-8 as default encoding
/etc/nginx/sites-available/simplesol.conf
upstream 192.168.8.5 {
server unix:/home/webadmin/adrienne/run/gunicorn.sock fail_timeout=0;
}
server {
listen 80;
server_name 192.168.8.5 ;
client_max_body_size 4G;
access_log /home/webadmin/logs/nginx-access.log;
error_log /home/webadmin/logs/nginx-error.log;
location /static/ {
autoindex on;
alias /home/webadmin/static/;
}
location /media/ {
alias /home/webadmin/media/;
location / {
# an HTTP header important enough to have its own Wikipedia entry:
# http://en.wikipedia.org/wiki/X-Forwarded-For
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
# enable this if and only if you use HTTPS, this helps Rack
# set the proper protocol for doing redirects:
#proxy_set_header X-Forwarded-Proto https;
# pass the Host: header from the client right along so redirects
# can be set properly within the Rack application
proxy_set_header Host $http_host;
# we don't want nginx trying to do something clever with
# redirects, we set the Host: header above already.
proxy_redirect off;
# set "proxy_buffering off" *only* for Rainbows! when doing
# Comet/long-poll stuff. It's also safe to set if you're
# using only serving fast clients with Unicorn + nginx.
# Otherwise you _want_ nginx to buffer responses to slow
# clients, really.
proxy_buffering off;
# Try to serve static files from nginx, no point in making an
# *application* server like Unicorn/Rainbows! serve static files.
if (!-f $request_filename) {
proxy_pass http://192.168.8.5;
break;
}
}
# Error pages
error_page 500 502 503 504 /500.html;
location = /500.html {
root /home/webadmin/SimpleSolWebsite/static/;
}
}
gunicorn_start.bash
#!/bin/bash
NAME="django_app"
DJANGODIR=/home/ubuntu/sample_project
SOCKFILE=/home/ubuntu/django_env/run/gunicorn.sock
USER=ubuntu
GROUP=ubuntu
NUM_WORKERS=3
DJANGO_SETTINGS_MODULE=sample_project.settings
DJANGO_WSGI_MODULE=sample_project.wsgi
echo "Starting $NAME as `whoami`"
cd $DJANGODIR
source /home/ubuntu/django_env/bin/activate
export DJANGO_SETTINGS_MODULE=$DJANGO_SETTINGS_MODULE
export PYTHONPATH=$DJANGODIR:$PYTHONPATH
RUNDIR=$(dirname $SOCKFILE)
test -d $RUNDIR || mkdir -p $RUNDIR
exec gunicorn ${DJANGO_WSGI_MODULE}:application \
--name $NAME \
--workers $NUM_WORKERS \
--user=$USER --group=$GROUP \
--bind=unix:$SOCKFILE \
--log-level=debug \
--log-file=-
Is there something wrong with my configuration files? I don't know where I went wrong and I haven't had any success on google. Thanks in advance for any insight you have for me!
gunicorn_supervisor_log
[2018-03-14 22:23:22 +0000] [25559] [DEBUG] GET /contact/
[2018-03-14 22:23:51 +0000] [10934] [DEBUG] POST /contact/
[2018-03-14 15:24:21 -0700] [24869] [CRITICAL] WORKER TIMEOUT (pid:10934)
[2018-03-14 22:24:21 +0000] [10934] [INFO] Worker exiting (pid: 10934)
[2018-03-14 15:24:21 -0700] [23688] [INFO] Booting worker with pid: 23688
Contacts App
models.py
from django.db import models
class Contacts(models.Model):
contact_name = models.CharField(max_length=256, default='contact name')
phone_number = models.CharField(max_length=15)
phone_ext = models.CharField(max_length=10, default='ext', blank="True")
email = models.EmailField()
comments = models.TextField()
company_name = models.CharField(max_length=250, default='company name')
forms.py
from django import forms
from contacts.models import Contacts
from django.forms import ModelForm
from django.db import models
class ContactForm(forms.ModelForm):
class Meta:
model = Contacts
fields = "__all__"
views.py
from django.shortcuts import render
from django.views.generic.edit import FormView
from contacts.forms import ContactForm
from django.views.generic import TemplateView
from exchangelib import *
from exchangelib.items import *
class ContactRequestView(FormView):
template_name = 'contact_form.html'
form_class = ContactForm
success_url = '/contact/thanks/'
def form_valid(self, form):
credentials = Credentials(
username='simplesol.com\\jbobst',
password='password'
)
account = Account(
primary_smtp_address='[email protected]',
credentials=credentials,
autodiscover=True,
access_type=DELEGATE
)
audit_request = ''
for k in form.cleaned_data:
audit_request += k + ' = ' + form.cleaned_data[k] + '\n'
m = Message(
account=account,
subject='You have a new site audit request',
body= audit_request,
to_recipients=
['[email protected]','[email protected]'],
)
m.send_and_save()
form.save()
return super().form_valid(form)
class ContactThanksView(TemplateView):
template_name = 'contact_thanks.html'
Answer
Gunicorn's default timeout is 30 seconds
Workers silent for more than this many seconds are killed and restarted.
If a worker is killed/restarted the connection to the nginx gets terminated and nginx would produce the error that you experience
*344 upstream prematurely closed connection while reading response header from upstream
This is confirmed by the error you see in gunicorn's logs:
[2018-03-14 22:23:51 +0000] [10934] [DEBUG] POST /contact/
[2018-03-14 15:24:21 -0700] [24869] [CRITICAL] WORKER TIMEOUT (pid:10934)
So either modify you code to complete everything in ~30 seconds (better) or adjust the timeout (worse)