code: func standardWebExposure(app *App) *twelvefactor.Exposure {
  	ports := []twelvefactor.Port{
  		{
  			Container: 8080,
  			Host:      80,
  			Protocol:  &twelvefactor.HTTP{},
  		},
  	}
  
  	// If a certificate is attached to the "web" process, add an SSL port.
  	if cert, ok := app.Certs[webProcessType]; ok {
  		ports = append(ports, twelvefactor.Port{
  			Container: 8080,
  			Host:      443,
  			Protocol: &twelvefactor.HTTPS{
  				Cert: cert,
  			},
  		})
  	}
  
  	return &twelvefactor.Exposure{
  		External: app.Exposure == exposePublic,
  		Ports:    ports,
  	}
  }
docs: // standardWebExposure generates a scheduler.Exposure for a web process in the
  // standard Procfile format.