Deploying on Linux

Deploying A Lona Script

In this section we will deploy a simple Lona Script using systemd and Apache2 as reverse proxy

Lona

# installing the necessary debian/ubuntu packages
$ sudo apt install apache2 python3 python3-venv

# setup /srv/lona and python virtualenv
$ sudo mkdir -p /srv/lona
$ sudo python3 -m venv /srv/lona/env
$ source /srv/lona/env/bin/activate
$ (env) pip install lona

# setup lona script
$ sudo touch /srv/lona/my-script.py

# change ownership of /srv/lona to www-data
$ sudo chown -R www-data:www-data /srv/lona

# /srv/lona/my-script.py

from lona.html import HTML, Button, Div, H1
from lona import LonaApp, LonaView

app = LonaApp(__file__)

app.settings.MAX_RUNTIME_THREADS = 50
app.settings.MAX_WORKER_THREADS = 100
app.settings.MAX_STATIC_THREADS = 20


@app.route('/')
class MyView(LonaView):
    def handle_request(self, request):
        message = Div('Button not clicked')
        button = Button('Click me!')

        html = HTML(
            H1('Click the button!'),
            message,
            button,
        )

        self.show(html)

        # this call blocks until the button was clicked
        input_event = self.await_click(button)

        if input_event.node == button:
            message.set_text('Button clicked')

        return html


if __name__ == '__main__':
    app.run(port=8080)

Apache2

$ sudo a2enmod headers rewrite proxy proxy_wstunnel proxy_http proxy_balancer lbmethod_byrequests

# /etc/apache2/sites-available/lona.conf
# needed modules: headers rewrite proxy proxy_wstunnel proxy_http proxy_balancer lbmethod_byrequests

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # application
    Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED

    <Proxy balancer://httprewrite>
        BalancerMember http://localhost:8080 route=1
        ProxySet stickysession=ROUTEID
    </Proxy>

    <Proxy balancer://wsrewrite>
        BalancerMember ws://localhost:8080 route=1
        ProxySet stickysession=ROUTEID
    </Proxy>

    RewriteEngine On

    RewriteCond %{HTTP:Upgrade} =websocket [NC]
    RewriteRule (.*) balancer://wsrewrite%{REQUEST_URI} [P,L]

    RewriteCond %{HTTP:Upgrade} !=websocket [NC]
    RewriteRule (.*) balancer://httprewrite%{REQUEST_URI} [P,L]
</VirtualHost>

$ sudo a2ensite lona.conf

Systemd

# /etc/systemd/system/lona-server.service

[Unit]
Description=Lona Server

[Service]
User=www-data
Type=simple
WorkingDirectory=/srv/lona/
ExecStart=/srv/lona/env/bin/python /srv/lona/my-script.py

[Install]
WantedBy=multi-user.target

$ sudo systemctl enable lona-server.service
$ sudo systemctl start lona-server.service

Deploying A Lona Project

In this section we will deploy lona-project-template using Apache2 and systemd.

Lona collects all static file at startup once and places them in /srv/lona/static to make them available for Apache.

The Lona server service sets up a Lona Shell Server using a unix domain socket in /srv/lona/lona-project-template/lona_project for debugging and monitoring.

When the project is deployed like defined here, you can attach a Lona Shell when the server is running.

$ sudo /srv/lona/lona-project-template/env/bin/rlpython file:///srv/lona/lona-project-template/lona_project/socket

Lona

# installing the necessary debian/ubuntu packages
$ sudo apt install apache2 build-essential python3 python3-venv

# setup /srv/lona and python virtualenv
$ sudo mkdir -p /srv/lona
$ sudo mkdir -p /srv/lona/static
$ sudo git clone https://github.com/lona-web-org/lona-project-template /srv/lona/lona-project-template
$ cd /srv/lona/lona-project-template
$ sudo make env

# change ownership of /srv/lona to www-data
$ sudo chown -R www-data:www-data /srv/lona

Apache2

$ sudo a2enmod headers rewrite proxy proxy_wstunnel proxy_http proxy_balancer lbmethod_byrequests

# /etc/apache2/sites-available/lona.conf
# needed modules: headers rewrite proxy proxy_wstunnel proxy_http proxy_balancer lbmethod_byrequests

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    # static files
    DocumentRoot /srv/lona/static
    Alias /static /srv/lona/static

    <Directory /srv/lona/static>
        Require all granted
    </Directory>

    # application
    Header add Set-Cookie "ROUTEID=.%{BALANCER_WORKER_ROUTE}e; path=/" env=BALANCER_ROUTE_CHANGED

    <Proxy balancer://httprewrite>
        BalancerMember http://localhost:8080 route=1
        ProxySet stickysession=ROUTEID
    </Proxy>

    <Proxy balancer://wsrewrite>
        BalancerMember ws://localhost:8080 route=1
        ProxySet stickysession=ROUTEID
    </Proxy>

    RewriteEngine On

    RewriteCond %{HTTP:Upgrade} =websocket [NC]
    RewriteRule !^static($|/) balancer://wsrewrite%{REQUEST_URI} [P,L]

    RewriteCond %{HTTP:Upgrade} !=websocket [NC]
    RewriteRule !^static($|/) balancer://httprewrite%{REQUEST_URI} [P,L]
</VirtualHost>

$ sudo a2ensite lona.conf

Systemd

# /etc/systemd/system/lona-server.service

[Unit]
Description=Lona Server

[Service]
User=www-data
Type=simple
WorkingDirectory=/srv/lona/lona-project-template/lona_project
ExecStartPre=/srv/lona/lona-project-template/env/bin/lona collect-static /srv/lona/static/ -s settings.py deployment_settings.py --clean
ExecStart=/srv/lona/lona-project-template/env/bin/lona run-server --host=localhost --port=8080 -s settings.py deployment_settings.py --shell-server-url=file://socket

[Install]
WantedBy=multi-user.target

$ sudo systemctl enable lona-server.service
$ sudo systemctl start lona-server.service