BlueMix not starting due to health check timeout

I'm using Go to try create a simple 'hello world'-eque script using IBM's BlueMix. I've been able to use their hello world script which runs fine, however upon writing my own it fails.

I'm aware that you need to take the environment variable for the port, which is what I've done, however with this in place, the check is still unable to start the service.

package main

import (
    "io"
    "net/http"
    "log"
    "os"
    "fmt"
)

const (
    DEFAULT_PORT = "4001"
    DEFAULT_HOST = "localhost"
)

func HelloServer(w http.ResponseWriter, req *http.Request) {
    io.WriteString(w, "hello, world!\n")
}

func main() {
    http.HandleFunc("/hello", HelloServer)

    var port string
    if port = os.Getenv("VCAP_APP_PORT"); len(port) == 0 {
        port = DEFAULT_PORT
    }

    var host string
    if host = os.Getenv("VCAP_APP_HOST"); len(host) == 0 {
        host = DEFAULT_HOST
    }


    log.Printf("Using host %v+\n", host)
    log.Printf("Using port %v+\n", port)
    fmt.Println("######" + port)

    err := http.ListenAndServe(host+":"+port, nil)
    if err != nil {
        log.Printf("ListenAndServe: ", err)
    }
}

Any help as to why this program is failing is greatly appreciated.

-- update --

The output of cf logs app --recent is:

2015-08-13T16:47:36.36+0100 [DEA/10]     OUT Removing crash for app with id ae803621-0b84-48d2-b3fd-6067053b40a6
2015-08-13T16:47:36.36+0100 [DEA/10]     OUT Stopping app instance (index 0) with guid ae803621-0b84-48d2-b3fd-6067053b40a6
2015-08-13T16:47:36.36+0100 [DEA/10]     OUT Stopped app instance (index 0) with guid ae803621-0b84-48d2-b3fd-6067053b40a6
2015-08-13T16:53:38.29+0100 [DEA/87]     OUT Starting app instance (index 0) with guid ae803621-0b84-48d2-b3fd-6067053b40a6
2015-08-13T16:54:02.13+0100 [DEA/87]     ERR Instance (index 0) failed to start accepting connections
2015-08-13T16:54:02.18+0100 [API/0]      OUT App instance exited with guid ae803621-0b84-48d2-b3fd-6067053b40a6 payload: {"cc_partition"=>"default", "droplet"=>"ae803621-0b84-48d2-b3fd-6067053b40a6", "version"=>"2ed88562-d12c-4391-ae8f-5fd8475cc350", "instance"=>"e4f99db81d194b1bb865a9e55f0a1d54", "index"=>0, "reason"=>"CRASHED", "exit_status"=>127, "exit_description"=>"failed to accept connections within health check timeout", "crash_timestamp"=>1439481242}
2015-08-13T16:54:02.21+0100 [API/10]     OUT App instance exited with guid ae803621-0b84-48d2-b3fd-6067053b40a6 payload: {"cc_partition"=>"default", "droplet"=>"ae803621-0b84-48d2-b3fd-6067053b40a6", "version"=>"2ed88562-d12c-4391-ae8f-5fd8475cc350", "instance"=>"e4f99db81d194b1bb865a9e55f0a1d54", "index"=>0, "reason"=>"CRASHED", "exit_status"=>127, "exit_description"=>"failed to accept connections within health check timeout", "crash_timestamp"=>1439481242}

Solution

The above program I wrote is correct and runs as it should. The issue was that the procfile was not correctly set up. The procfile blueMix uses in its example Go program is web: gohelloworld.

gohelloworld can be found in the godeps/Godeps.json file, as the ImportPath value. So when generating your godep file, the generated value from ImportPath is the value you should place in your procfile.

In my case, it should have been: web: test.