title: why uvicorn port 80 options works on another port?
body: <p>I tried fastApi and uvicorn.</p>
  <p>But I'm wondering why when i execute uvicorn in port 80, it works on port 52384.
  52384 shows the api response but 80 does not.</p>
  <p>in the dockerfile, I added <code>EXPOSE 80 80</code>.</p>
  <pre><code>// terminal
  vscode ➜ /app (master ✗) $ lsof -i:80
  vscode ➜ /app (master ✗) $ uvicorn main:app --port 80
  INFO:     Started server process [1115]
  INFO:     Waiting for application startup.
  INFO:     Application startup complete.
  INFO:     Uvicorn running on http://127.0.0.1:80 (Press CTRL+C to quit)
  INFO:     127.0.0.1:52384 - &quot;GET / HTTP/1.1&quot; 200 OK
  </code></pre>
  <pre class="lang-py prettyprint-override"><code>// python 
  from typing import Optional
  
  from fastapi import FastAPI
  
  app = FastAPI()
  
  
  @app.get(&quot;/&quot;)
  def read_root():
      return {&quot;Hello&quot;: &quot;World&quot;}
  
  
  @app.get(&quot;/items/{item_id}&quot;)
  def read_item(item_id: int, q: Optional[str] = None):
      return {&quot;item_id&quot;: item_id, &quot;q&quot;: q}
  </code></pre>