2.7.4. Proxying traffic to web apps

On the hosting is available the ability to proxying HTTP traffic to the local IP address, so you can run apps in PHP, Python and Go.

We give you a unique local IP address of the form 127.*.*.*.*, where * is any number between 0 and 255, and the default port is 3000. You use these values in your app — you specify them in the run command or directly in the code.

The order in which the request is processed:

1. Request comes to the shared server on port 80 or 443.
2. Based on the hostname, forwards to the app to the local IP address.
3. App receives the data, processes it, and returns a response.

The real IP address of the visitor is passed in the X-REAL-IP header.

1. Open the "Site settings" section.
2. Switch "Web server" to "Traffic proxying" and save the changes:
3. Locate your app files on the hosting in the desired directory.
4. Open the "Web application settings" section.
5. Specify the directory and command to launch your application:
   • Launch directory — path to the directory from which your app should launch. If left blank, the site root directory will be used.
   • Run command — command to run your app. You can use the standard Bash control operators (&&, ;, ||) to combine multiple sequential commands. In the run command or in the code of the app itself, use the local IP address and port from the "Proxying HTTP traffic to the application" block:
6. Save the changes and test the app's operation:

In the "Application logs" block, you can monitor real-time logs as the app launches and runs.

Launching Django 4.2 on Python 3.10:

1. In the "Hosting account settings" section (or "Hosting → Hosting account settings" section), set the Python version to 3.10 or higher and save your changes.
2. Connect to the hosting via SSH.
3. Install Django:

   pip install --user Django

4. Navigate to the subdomain directory where your project files will be located:

   cd example.com/sub

5. Create the new project named project:

   django-admin startproject project .

6. Apply migrations:

   python manage.py migrate

7. Edit your project's settings file project/settings.py and in the line ALLOWED_HOSTS = [] specify in square brackets in single quotes the address of your site 'sub.example.com'.
8. On the web app settings page, specify the run command:

   python3.10 manage.py runserver 127.*.*.*:3000

   In the command, instead of 127.*.*.*.* and 3000, use the IP address and port from the web app settings page.

9. Save the changes, launch the app and test the site's operation.

If successful, the site should display a page with the text "The install worked successfully! Congratulations!".

Launching Flask 2.3 on Python 3.10:

1. In the "Hosting account settings" section (or "Hosting → Hosting account settings" section), set the Python version to 3.10 or higher and save your changes.
2. Connect to the hosting via SSH.
3. Navigate to the subdomain directory where your project files will be located:

   cd example.com/sub

4. Create a Python virtual environment:

   python -m venv .venv

5. Activate the created virtual environment:

   source .venv/bin/activate

6. Install Flask:

   pip install --user Flask

7. Deactivate the virtual environment:

   deactivate

8. Create the hello.py file with these contents (example "A Minimal Application" from official documentation):

   from flask import Flask
   
   app = Flask(__name__)
   
   @app.route("/")
   def hello_world():
       return "<p>Hello, World!</p>"

9. On the web app settings page, specify the run command:

   source .venv/bin/activate && python3.10 -m flask --app hello.py run --host 127.*.*.* --port 3000

   In the command, instead of 127.*.*.*.* and 3000, use the IP address and port from the web app settings page.

10. Save the changes, launch the app and test the site's operation.

If successful, the site will display the text "Hello, World!".

Launching a simple application on Go 1.20:

1. In the "Hosting account settings" section (or "Hosting → Hosting account settings" section), set the Go version to 1.20 or higher and save your changes.
2. Connect to the hosting via SSH.
3. Navigate to the subdomain directory where your project files will be located:

   cd example.com/sub

4. Create the simple.go file with this content (example "Introducing the net/http package (an interlude)" from official documentation):

   package main
   
   import (
       "fmt"
       "log"
       "net/http"
   )
   
   func handler(w http.ResponseWriter, r *http.Request) {
       fmt.Fprintf(w, "Hi there, I love %s!", r.URL.Path[1:])
   }
   
   func main() {
       http.HandleFunc("/", handler)
       log.Fatal(http.ListenAndServe("127.*.*.*:3000", nil))
   }

   In the line log.Fatal(http.ListenAndServe("127.*.*.*:3000", nil)), instead of 127.*.*.*.* and 3000, use the IP address and port from the web app settings page.

5. Compile the created file:

   go build simple.go

6. Set permissions to 750 for the compiled file:

   chmod 750 simple

7. On the web app settings page, specify the run command:

   ./simple

8. Save the changes, launch the app and test the site's operation.

If successful, the site should display the text "Hi there, I love!" with the name of the page you accessed.