examples

Examples

Simple server

Compile the example

$ go build -o simple_server examples/simple.go

Run it

$ ./simple_server
2015/03/22 20:03:29 PID: 2710 localhost:4242

Make a request

$ curl http://localhost:4242/hello
WORLD!

Change the handler - eg. replace the ! with a ?

$ go build -o simple_server examples/simple.go
$ kill -1 2710

The server log says something like:

2015/03/22 20:04:10 2710 Received SIGHUP. forking.
2015/03/22 20:04:10 2710 Received SIGTERM.
2015/03/22 20:04:10 2710 Waiting for connections to finish...
2015/03/22 20:04:10 PID: 2726 localhost:4242
2015/03/22 20:04:10 accept tcp 127.0.0.1:4242: use of closed network connection
2015/03/22 20:04:10 Server on 4242 stopped

Make another request

$ curl http://localhost:4242/hello
WORLD?

TLS

Create local cert and key file:

go run $GOROOT/src/crypto/tls/generate_cert.go --host=localhost

Compile the example

$ go build -o tls_server examples/tls.go

Run it

$ ./tls_server
2015/03/23 19:43:29 PID: 21710 localhost:4242

Make a request (-k to disable certificate checks in curl)

$ curl -k https://localhost:4242/hello
WORLD!

The rest is like the simple server example: modify the tls.go code, build, send SIGHUP, and make another request.

Hooking into the signal handling

If you want to time certain actions before or after the server does something based on a signal it received you can hook your own functions into the signal handling of the endless server.

There is a PRE_SIGNAL and a POST_SIGNAL hook dor each signal. These are exposed as lists of parameterless functions:

func preSigUsr1() {
    log.Println("pre SIGUSR1")
}

If you want to have this function executed before SIGUSR1 you would add it to the hooks like this:

srv := endless.NewServer("localhost:4244", mux)
srv.SignalHooks[endless.PRE_SIGNAL][syscall.SIGUSR1] = append(
	srv.SignalHooks[endless.PRE_SIGNAL][syscall.SIGUSR1],
	preSigUsr1)

then build, and run it

$ go build -o hook_server examples/hook.go
$ ./hook_server
2015/04/06 20:32:13 1489 localhost:4244

now send SIGUSR1

kill -SIGUSR1 1489

and you should see something like this

2015/04/06 20:33:07 pre SIGUSR1
2015/04/06 20:33:07 1489 Received SIGUSR1.
2015/04/06 20:33:07 post SIGUSR1

Running several servers (eg on several ports)

This is probably less useful as you could always run separate servers - but in case you need to start more than one listener from one binary it will also work with endless - pretty much the same way it works in the simple and TLS examples.