readme updates for new options and a few usage details

Author: ivolucien

README.md

@@ -15,8 +15,7 @@ $ npm install express-graceful-exit
 
 v0.X.X versions are backwards API compatible, with these minor behavior changes:
 1. Process exit is called in a `setTimeout` block from v0.2.0 forward, so the timing is slightly different between v0.1.0 to v0.2.x+.
-2. After exit was triggered, incoming requests were mismanaged prior to v0.5.0.
-As of v0.5.0 incoming requests are dropped cleanly by default and have even better options available, such as responding with a custom error.
+2. After exit was triggered, incoming requests were mismanaged prior to v0.5.0. <br> As of v0.5.0 incoming requests are dropped cleanly by default, with new options such as responding with a custom error and/or performing one last request per connection.
 
 ## Usage
 
@@ -33,6 +32,9 @@ var express = require('express');
 var app = express();
 var gracefulExit = require('express-graceful-exit');
 
+var server = app.listen(port)
+
+gracefulExit.init(server) // use init() if configured to exit the process after timeout
 app.use(gracefulExit.middleware(app));
 ````
 
@@ -45,7 +47,7 @@ This function tells express to accept no new requests and gracefully closes the
 process.on('message', function(message) {
   if (message === 'shutdown') {
     gracefulExit.gracefulExitHandler(app, server, {
-        socketio: app.settings.socketio
+        <see options below>
     });
   }
 });
@@ -66,11 +68,12 @@ The following options are available:
  __log__             |  Print status messages and errors to the logger  |  false
  __logger__          |  Function that accepts a string to output a log message  |  console.log
  __callback__        |  Optional function that is called with the exit status code once express has shutdown, gracefully or not <br> Use in conjunction with  `exitProcess: false` when the caller handles process shutdown  |  no-op
- __exitProcess__     |  If true, the module calls `process.exit()` when express has shutdown, gracefully or not  |  true
+ __performLastRequest__ |  Process the first request received per connection after exit starts, and include a connection close header for callers and load balancers. <br> `false` is the existing behavior, deprecated as of v0.5.0 |  false
+ __errorDuringExit__ |  Respond to incoming requests with an error instead of silently dropping them. <br> `false` is the existing behavior, deprecated as of v0.5.0  |  false
+ __getRejectionError__  |  Function returning rejection error for incoming requests during graceful exit | `function () { return new Error('Server unavailable, no new requests accepted during shutdown') }`
+ __exitProcess__      |  If true, the module calls `process.exit()` when express has shutdown, gracefully or not  |  true
  __exitDelay__       |  Wait timer duration in the final internal callback (triggered either by gracefulExitHandler or the hard exit handler) if `exitProcess: true`  |  10ms
- __respondDuringExit__ |  Respond to incoming requests with an error (instead of silently dropping them) | false (see below)
- __unavailableError__  |  Function returning rejection error for incoming requests during graceful exit | `function () { return new Error('Server unavailable, no new requests accepted during shutdown') }`
- __suicideTimeout__  |  How long to wait before giving up on graceful shutdown, then returns exit code of 1  |  2m 10s (130s)
+  __suicideTimeout__ |  How long to wait before giving up on graceful shutdown, then returns exit code of 1  |  2m 10s (130s)
  __socketio__        |  An instance of `socket.io`, used to close all open connections after timeout  |  none
  __force__           |  Instructs the module to forcibly close sockets once the suicide timeout elapses. <br> For this option to work you must call `gracefulExit.init(server)` when initializing the HTTP server  |  false
 
@@ -79,11 +82,8 @@ The following options are available:
 To gracefully exit this module does the following things:
 
 1. Closes the http server so no new connections are accepted
-2. Closes existing connections that use the Keep-Alive header</br>
-The HTTP status code of 502 is returned, so nginx, ELB, etc will try with an active server</br>
-If `respondDuringExit` is set to true, a response is sent with `Connection: close`
-3. If a socket.io instance is passed in the options, all connected clients are immediately disconnected (socket.io v0.X through v1.4.x support)</br>
-The client should have code to reconnect on disconnect
+2. Sets connection close header for Keep-Alive connections, if configured for responses</br> The HTTP status code of 502 is returned, so nginx, ELB, etc will try with an active server</br> If `errorDuringExit` and/or `performLastRequest` are set to true, a response is sent with a `Connection: close` header
+3. If a socket.io instance is passed in the options, all connected clients are immediately disconnected (socket.io v0.X through v1.4.x support)</br> The client should have code to reconnect on disconnect
 4. Once the server fully disconnects or the hard exit timer runs
     1. If all in-flight requests have resolved and/or disconnected, the exit handler returns `0`
     2. OR if any connections remain after `suicideTimeout` ms, the handler returns `1`