Serve stuff over the interwebs with Go in a PHP-like fashion.
- Simply create and edit .go files in a straight-forward directory structure
- A directory with a
servlet.gofile is considered an endpoint.func ServeHTTP(r ghp.Request, w ghp.Response)will be called to handle HTTP requests. - Hot-reloading at runtime without the need to restart a server.
- Source graph optionally computed live for perfect dependency knowledge — change a source file in a far-away dependency and have appropriate GHP endpoints be recompiled and reloaded.
- Dead-simple Zero-Downtime Restarts out of the box
layout.ghp:
<html>
<body>
<h1>{.URL}</h1>
{.Content}
</body>
</html>page.ghp:
---
parent: parent.ghp
---
<p>Time: {timestamp}</p>$ curl -i http://localhost:8001/page.ghp
HTTP/1.1 200 OK
Date: Sun, 04 Nov 2018 23:27:01 GMT
Content-Length: 84
Content-Type: text/html; charset=utf-8
<html>
<body>
<h1>/page.ghp</h1>
<p>Time: 1541374021</p>
</body>
</html>
bar/servlet.go:
package main
import "ghp"
func ServeHTTP(r ghp.Request, w ghp.Response) {
w.WriteString("Hello world")
}$ curl -i http://localhost:8001/bar/
HTTP/1.1 200 OK
Date: Sun, 04 Nov 2018 23:23:53 GMT
Content-Length: 11
Content-Type: text/plain; charset=utf-8
Hello world
Servlets can additionally provide the optional
StartServlet and StopServlet functions, called when a servlet instance
has been started and is stopping, respectively.
StopServlet is called just after a servlet has been disconnected from
receiving any new requests. This might happen when a new instance (version)
of the same servlet has been started, or when GHP is shutting down.
During a graceful shutdown of GHP,
for instance from SIGHUP or ZDR,
or when a servlet instance is replaced with a newer version, StopServlet
may block while completing any ongoing work, like shutting down a websocket
or writing data to disk.
StartServlet can be useful for setting up shared resources, or for picking
up shared state from a past servlet instance.
GHP supports seamless restarts where the server never stops listening for
connections. ZDR is enabled by default and doesn't require you to launch
ghp processes in any special way.
- Coordination is per directory served. i.e. a GHP process serving a certain directory will coordinate with any other GHP process that is launched to serve the same directory.
- Works by transferring ownership of listener file descriptors via a Unix socket, thus ZDR works on any POSIX system where Unix sockets are enabled.
- Gracefully shuts down an older process, completeing in-flight requests while at the same the newer process starts serving new requests concurrently.
- Servlets can hook into this system by simply providing the optional
StopServletandStartServletfunctions. - Coordination can be customized using a config file by setting
zdr.groupto a unique string that is unique to the host machine.
Try it with the example app:
# Terminal 1 Terminal 1
$ cd ghp/example && ../bin/ghp
listening on http://[::1]:8002
listening on http://localhost:8002
listening on https://localhost:8443 $ cd ghp/example && ../bin/ghp
graceful shutdown initiated listening on http://[::1]:8002
graceful shutdown completed listening on http://localhost:8002
$ listening on https://localhost:8443
$ ../bin/ghp graceful shutdown initiated
listening on http://[::1]:8002 graceful shutdown completed
listening on http://localhost:8002 $
listening on https://localhost:8443 $ pkill -HUP ghp
graceful shutdown initiated
graceful shutdown completed
$
When switching processes, try requesting
http://localhost:8002/servlet-sleeper/ which responds very slowly piece by
piece. You'll notice that even when you start another GHP process that takes
over, an ongoing requests is patiently served til completion.
./build.sh
(cd example && ../bin/ghp -dev)Open http://localhost:8002/
Edit go files in example/pub and reload your web browser.
- Terminal 1:
autorun -r=500 ghp/*.go -- ./build.sh -noget - Terminal 2:
(cd example && autorun ../bin/ghp -- ../bin/ghp -dev)
Now just edit source files and GHP will be automatically rebuilt and restarted.
Get autorun here