Use env vars to get information in Go API

Author: fwsGonzo

compute.json

@@ -82,7 +82,6 @@
 		"address_space": 1800,
 		"remapping": ["0xC000000000", 256],
 		"max_memory": 64,
-		"relocate_fixed_mmap": false,
 		"concurrency": 4,
 		"storage": true
 	},

go/goexample/goexample.go

@@ -53,6 +53,7 @@ func main() {
 
 	varnish.StorageRegister("my_storage", my_storage)
 
-	fmt.Println("Go Compute Example ready (", os.Args[2], ")")
+	// Storage/request can be determined from environment variable KVM_TYPE
+	fmt.Println("Go Compute Example ready (", os.Getenv("KVM_TYPE"), ")")
 	varnish.WaitForRequests()
 }

go/varnish/api.go

@@ -32,12 +32,14 @@ import "C"
 import (
 	"errors"
 	"os"
-	"strings"
 	"unsafe"
 )
 
 func IsLinuxMain() bool {
-	return strings.Contains(os.Args[0], "/")
+	// The presence of environment variable KVM_TYPE means we are running
+	// in a KVM sandbox. Simply check if it exists:
+	_, ok := os.LookupEnv("KVM_TYPE")
+	return !ok
 }
 
 type GetHandler func(string, string)