How to Serve Falcon with Gunicorn and Nginx in Ubuntu

Now its time to install the Flacon.

(venv) root@linuxhelp1:~/falcon_app# pip install --no-binary :all: falcon
The directory ' /home/user1/.cache/pip/http'  or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo' s -H flag.
The directory ' /home/user1/.cache/pip'  or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo' s -H flag.
Collecting falcon
Downloading falcon-1.1.0.tar.gz (141kB)
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Collecting six> =1.4.0 (from falcon)
Downloading six-1.10.0.tar.gz
Collecting python-mimeparse> =1.5.2 (from falcon)
Downloading python-mimeparse-1.6.0.tar.gz
Installing collected packages: six, python-mimeparse, falcon
Running setup.py install for six ... done
Running setup.py install for python-mimeparse ... done
Running setup.py install for falcon ... done
Successfully installed falcon-1.1.0 python-mimeparse-1.6.0 six-1.10.0

Also install Gunicorn with the following command.

(venv) root@linuxhelp1:~/falcon_app# pip install gunicorn
The directory ' /home/user1/.cache/pip/http'  or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo' s -H flag.
The directory ' /home/user1/.cache/pip'  or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo' s -H flag.
Collecting gunicorn
Downloading gunicorn-19.6.0-py2.py3-none-any.whl (114kB)
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Installing collected packages: gunicorn
Successfully installed gunicorn-19.6.0

Write a simple web application script using Falcon.

(venv) root@linuxhelp1:~/falcon_app# nano main.py

import falcon

class TestResource(object):
def on_get(self, req, res):
" " " Handles all GET requests." " " 
res.status = falcon.HTTP_200 # This is the default status
res.body = (' This is me, Falcon, serving a resource!' )

# Create the Falcon application object
app = falcon.API()

# Instantiate the TestResource class
test_resource = TestResource()

# Add a route to serve the resource
app.add_route(' /test' , test_resource)

Now you can access the Falcon application with Gunicorn. It enable web application at 0.0.0.0 on port 5000 as shown below,

(venv) root@linuxhelp1:~/falcon_app# gunicorn -b 0.0.0.0:5000 main:app --reload
[2016-11-17 16:41:41 +0530] [4552] [INFO] Starting gunicorn 19.6.0
[2016-11-17 16:41:41 +0530] [4552] [INFO] Listening at: http://0.0.0.0:5000 (4552)
[2016-11-17 16:41:41 +0530] [4552] [INFO] Using worker: sync
[2016-11-17 16:41:41 +0530] [4555] [INFO] Booting worker with pid: 4555

Open the web browser with your IP address to check the web application output.

Now install Nginx for the proxy requests.

(venv) root@linuxhelp1:~/falcon_app# apt-get install nginx -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
nginx-common nginx-core
Suggested packages:
fcgiwrap nginx-doc
The following NEW packages will be installed:
nginx nginx-common nginx-core
0 upgraded, 3 newly installed, 0 to remove and 410 not upgraded.
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Create a new configuration file ' falcon_app.conf' in the /etc/nginx/sites-available directory. This file will configure Nginx to proxy all requests coming to your server' s IP address to the Gunicorn server of our Falcon application.

(venv) root@linuxhelp1:~/falcon_app# nano /etc/nginx/sites-available/flcon_app.conf

server {
listen 80 
server_name 192.168.5.154 

location / {
include proxy_params 
proxy_pass http://localhost:5000 
}
}

This configuration tells Nginx to listen on port 80 and proxy all the HTTP requests to http://localhost:5000, which is where Gunicorn will be listening.

Activate this configuration by creating a symbolic link to this file in the /etc/nginx/sites-enabled directory

(venv) root@linuxhelp1:~/falcon_app# ln -s /etc/nginx/sites-available/falcon_app.conf /etc/nginx/sites-enabled/falcon_app.conf

Then disable the default Nginx configuration file by removing its symlink from the /etc/nginx/sites-enabled directory.

(venv) root@linuxhelp1:~/falcon_app# rm /etc/nginx/sites-enabled/default

Make sure that there are no syntax errors.

(venv) root@linuxhelp1:~/falcon_app# nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

Restart Nginx to take effect.

(venv) root@linuxhelp1:~/falcon_app# systemctl restart nginx

Set permission to access port 80 through the server' s firewall.

(venv) root@linuxhelp1:~/falcon_app# ufw allow 80
Rules updated
Rules updated (v6)

Again start Gunicorn and change the listening address from 0.0.0.0 to localhost for preventing public access to Gunicorn.

(venv) root@linuxhelp1:~/falcon_app# gunicorn -b localhost:5000 main:app --reload
[2016-11-17 16:48:45 +0530] [5055] [INFO] Starting gunicorn 19.6.0
[2016-11-17 16:48:45 +0530] [5055] [INFO] Listening at: http://127.0.0.1:5000 (5055)
[2016-11-17 16:48:45 +0530] [5055] [INFO] Using worker: sync
[2016-11-17 16:48:45 +0530] [5058] [INFO] Booting worker with pid: 5058

(venv) root@linuxhelp1:~/falcon_app# nano /etc/systemd/system/falcon_app.service

[Unit]
Description=Gunicorn instance to serve the falcon application
After=network.target

[Service]
User=user1
Group=www-data
PIDFile=/tmp/gunicorn.pid
Environment=" PATH=/home/user1/falcon_app/venv/bin" 
WorkingDirectory=/home/user1/falcon_app
ExecStart=/home/user1/falcon_app/venv/bin/gunicorn --workers 3 -b localhost:5000 main:app
ExecReload=/bin/kill -s HUP $MAINPID
ExecStop=/bin/kill -s TERM $MAINPID

[Install]
WantedBy=multi-user.target

(venv) root@linuxhelp1:~/falcon_app# systemctl start falcon_app

(venv) root@linuxhelp1:~/falcon_app# systemctl enable falcon_app
Created symlink from /etc/systemd/system/multi-user.target.wants/falcon_app.service to /etc/systemd/system/falcon_app.service.

(venv) root@linuxhelp1:~/falcon_app# systemctl restart falcon_app