app.rb

require "sinatra"

# Sinatra defaults to localhost, which a health check outside the container cannot
# reach. Bind the injected port on every interface instead.
set :bind, "0.0.0.0"
set :port, ENV.fetch("PORT", 8080)

PAGE = <<~HTML
  <!doctype html>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width,initial-scale=1">
  <title>Live on velixir</title>
  <style>
    :root { color-scheme: dark; }
    body { margin:0; min-height:100vh; display:grid; place-items:center;
           background:#0b0b10; color:#e8e8ef;
           font:16px/1.6 ui-sans-serif,system-ui,-apple-system,Segoe UI,sans-serif; }
    main { max-width:34rem; padding:2.5rem 1.5rem; text-align:center; }
    h1 { font-size:1.6rem; margin:0 0 .5rem; letter-spacing:-.02em; }
    p { color:#a0a0b0; margin:.5rem 0; }
    code { background:#16161f; border:1px solid #26263a; border-radius:6px;
           padding:.15rem .4rem; font-size:.875em; color:#c7d2fe; }
    .dot { display:inline-block; width:.5rem; height:.5rem; border-radius:50%;
           background:#34d399; margin-right:.5rem; vertical-align:middle; }
  </style>
  <main>
    <p><span class="dot"></span>Ruby is running on velixir</p>
    <h1>Your first deploy worked.</h1>
    <p>This page is served by your own container, built from source. No Dockerfile was involved.</p>
    <p>Next: edit <code>app.rb</code>, then run <code>velixir deploy</code>.</p>
  </main>
HTML

get "/healthz" do
  "ok"
end

get "/" do
  PAGE
end