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Deploy Deno Apps

Deno is a popular Node alternative for back-end Javascript runtime environment known for its modern approach. Like Node, you don't need to compile your code beforehand.

There is no default deno compiler at system level. You have to install it first through deployment scripts.

warning

Serving Deno apps requires to be run via GLS, that's mean you have to listen from given PORT env/args. You also have to give network and any other relevant system permissions to the script.

Example​

The deployment script below installs the latest deno compiler and writes app.ts and serves that with --allow-net permissions.

https://github.com/domcloud/recipes/blob/master/deno.yml
source: clear
features:
  - deno latest
nginx:
  root: public_html/public
  passenger:
    enabled: "on"
    app_start_command: deno run --allow-net app.ts --port=$PORT
commands:
  - filename: app.ts
    content: |
      import { parse } from "https://deno.land/[email protected]/flags/mod.ts";

      const flags = parse(Deno.args, {
          string: ["port"],
          default: { port: "8080" },
      });

      const html_text = `
      <!DOCTYPE html>
      <html>
      <head>
          <title>Deno App</title>
          <link rel="stylesheet" href="//unpkg.com/bootstrap/dist/css/bootstrap.min.css">
      </head>
      <body class="p-5 text-center">
          <p><img src="//images.unsplash.com/photo-1465153690352-10c1b29577f8?fit=crop&w=200&h=200" 
                  class="img-fluid rounded-circle"></p>
          <h1 class="mb-3">Hello, world!</h1>
          <p>Serving from Deno version ${Deno.version.deno}</p>
          <p class="text-muted">DOM Cloud</p>
      </body>
      </html>
      `

      const server = Deno.listen({ port: parseInt(flags.port) });

      for await (const conn of server) {
        serveHttp(conn);
      }

      async function serveHttp(conn: Deno.Conn) {
        const httpConn = Deno.serveHttp(conn);
        for await (const requestEvent of httpConn) {
          requestEvent.respondWith(
            new Response(html_text, {
              headers: {
                  "content-type": "text/html",
              },
              status: 200,
            }),
          );
        }
      }

For existing deno apps, use this deployment script. Please adjust relevant fields such as the startup file (change app.ts), allowed features (change --allow-net) and how $PORT is delivered (either deno ... --port=$PORT or env PORT=$PORT deno ...).

https://github.com/domcloud/recipes/blob/master/deno-gls.yml
features:
  - deno latest
nginx:
  root: public_html/public
  passenger:
    enabled: "on"
    app_start_command: deno run --allow-net app.ts --port=$PORT

Use other Deno versions​

To switch Deno version use feature syntax like deno stable, deno beta, deno v1.13, etc. Check your current Deno version using deno --version in SSH.

features:
  - deno v1.13

Deno install scripts is powered by webi.

App Management​

Your app do not restarted automatically after file changes. To restart, run restart via SSH.

Environment variables can be set either using NGINX's env_var_list or ~/.bashrc. Usually your language framework also reads .env files.

See NGINX and App Daemon for more information about NGINX and App managements including restarting, environment variables, and other global limitations.

App Logging​

You can see app log from Check -> Check Process Logs tab. Only startup problems displayed in the browser.

Please use a proper logging mechanism such as the standard logging library then write it to a log file, or any other solution that suits you.

NGINX errors and traffic logs can be examined via Webmin or Check -> Check Process Logs tab.