Curl returning (52) with AWS + uWSGI + NGinx + Pyramid setup - nginx

Question

Been having this issue for days and hope someone will shed a light on it.
Basically I have set up a pyramid app using AWS EC2 with uWSGI and NGinx.
I have no issue with telnet as shown below:
$ telnet 127.0.0.1 3003
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Connection closed by foreign host.
Next when I tried curl, it showed the below result:
$ curl 127.0.0.1:3003
curl: (52) Empty reply from server
My production.ini file:
###
# wsgi server configuration
###
[server:main]
use = egg:uwsgi#main
host = 127.0.0.1
port = 3003
###
# logging configuration
# http://docs.pylonsproject.org/projects/pyramid/en/1.6-branch/narr/logging.html
###
[loggers]
keys = root, fruler
[handlers]
keys = console
[formatters]
keys = generic
[logger_root]
level = WARN
handlers = console
[logger_fruler]
level = WARN
handlers =
qualname = fruler
[handler_console]
class = StreamHandler
args = (sys.stderr,)
level = NOTSET
formatter = generic
[formatter_generic]
format = %(asctime)s %(levelname)-5.5s [%(name)s:%(lineno)s][%(threadName)s] %(message)s
[uwsgi]
socket = 127.0.0.1:3003
virtualenv = /home/ec2-user/env
die-on-term = 1
master = 1
daemonize = /home/ec2-user/env/FRuler/uwsgi.log
pidfile = /home/ec2-user/env/FRuler/pid_5000.pid
processes = 4
harakiri = 30
harakiri-verbose = true
limit-post = 5242880
post-buffering = 8192
My /etc/nginx/nginx.conf file:
user nginx;
worker_processes 1;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
include /etc/nginx/mime.types;
default_type application/octet-stream;
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
keepalive_timeout 65;
#gzip on;
#include /etc/nginx/conf.d/*.conf;
server {
#listen <aws.ip.address>:80;
listen 80;
server_name ec2-<aws.ip.address>.ap-southeast-1.compute.amazonaws.com;
#index index.html index.htm index.py;
access_log /var/log/nginx/<domain>.com.log;
error_log /var/log/nginx/<domain>.com.error;
root /home/ec2-user/;
charset utf-8;
location / {
uwsgi_pass 127.0.0.1:3003;
#proxy_pass http://127.0.0.1:3003;
include uwsgi_params;
}
location /static {
root /home/ec2-user/env/FRuler/fruler/;
}
}
}
After running the following command:
$ sudo ./bin/uwsgi --ini-paste-logged FRuler/production.ini
[uWSGI] getting INI configuration from FRuler/production.ini
The log file for uwsgi is as followed:
*** Starting uWSGI 2.0.12 (64bit) on [Sun May 8 21:58:22 2016] ***
compiled with version: 4.8.5 20150623 (Red Hat 4.8.5-4) on 05 May 2016 01:48:35
os: Linux-3.10.0-327.el7.x86_64 #1 SMP Thu Oct 29 17:29:29 EDT 2015
nodename: ip-172-31-29-104.ap-southeast-1.compute.internal
machine: x86_64
clock source: unix
pcre jit disabled
detected number of CPU cores: 1
current working directory: /home/ec2-user/env
writing pidfile to /home/ec2-user/env/FRuler/pid_5000.pid
detected binary path: /home/ec2-user/env/bin/uwsgi
uWSGI running as root, you can use --uid/--gid/--chroot options
*** WARNING: you are running uWSGI as root !!! (use the --uid flag) ***
your processes number limit is 3824
your memory page size is 4096 bytes
detected max file descriptor number: 1024
lock engine: pthread robust mutexes
thunder lock: disabled (you can enable it with --thunder-lock)
uwsgi socket 0 bound to TCP address 127.0.0.1:3003 fd 3
Python version: 3.4.1 (default, May 5 2016, 01:34:21) [GCC 4.8.5 20150623 (Red Hat 4.8.5-4)]
Set PythonHome to /home/ec2-user/env
*** Python threads support is disabled. You can enable it with --enable-threads ***
Python main interpreter initialized at 0xf78820
your server socket listen backlog is limited to 100 connections
your mercy for graceful operations on workers is 60 seconds
mapped 404800 bytes (395 KB) for 4 cores
*** Operational MODE: preforking ***
Loading paste environment: config:/home/ec2-user/env/FRuler/production.ini
WSGI app 0 (mountpoint='') ready in 0 seconds on interpreter 0xf78820 pid: 15848 (default app)
*** uWSGI is running in multiple interpreter mode ***
spawned uWSGI master process (pid: 15848)
spawned uWSGI worker 1 (pid: 15852, cores: 1)
spawned uWSGI worker 2 (pid: 15853, cores: 1)
spawned uWSGI worker 3 (pid: 15854, cores: 1)
spawned uWSGI worker 4 (pid: 15855, cores: 1)
I entered my AWS url into the browser and it show a 502 bad gateway error.
Is there anything in the config file that I edited wrongly?