From 59094cd5b7d13a0165f0a935bb4a83d4ff99d206 Mon Sep 17 00:00:00 2001
From: Sean Chittenden <sean@chittenden.org>
Date: Thu, 11 Aug 2016 00:51:07 -0700
Subject: [PATCH] Add HostID to the Host InfoStat struct returned from
 host.Info().

On supported hosts the value returned is a UUID (case preserving
from the value of the underlying OS).

For Linux this is generated once, randomly per boot.  For FreeBSD and
Darwin this is a more durable value that should persist across reboots.
---
 host/host.go         | 2 +-
 host/host_darwin.go  | 5 +++++
 host/host_freebsd.go | 5 +++++
 host/host_linux.go   | 5 +++++
 host/host_test.go    | 3 ++-
 5 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/host/host.go b/host/host.go
index 1a6545b..548e92e 100644
--- a/host/host.go
+++ b/host/host.go
@@ -25,7 +25,7 @@ type InfoStat struct {
 	PlatformVersion      string `json:"platformVersion"`
 	VirtualizationSystem string `json:"virtualizationSystem"`
 	VirtualizationRole   string `json:"virtualizationRole"` // guest or host
-
+	HostID               string `json:"hostid"`             // ex: uuid
 }
 
 type UserStat struct {
diff --git a/host/host_darwin.go b/host/host_darwin.go
index 199ea61..43c49b2 100644
--- a/host/host_darwin.go
+++ b/host/host_darwin.go
@@ -56,6 +56,11 @@ func Info() (*InfoStat, error) {
 		ret.Procs = uint64(len(procs))
 	}
 
+	values, err := common.DoSysctrl("kern.uuid")
+	if err == nil && len(values) == 1 && values[0] != "" {
+		ret.HostID = values[0]
+	}
+
 	return ret, nil
 }
 
diff --git a/host/host_freebsd.go b/host/host_freebsd.go
index 2159ae8..58a06c2 100644
--- a/host/host_freebsd.go
+++ b/host/host_freebsd.go
@@ -59,6 +59,11 @@ func Info() (*InfoStat, error) {
 		ret.Procs = uint64(len(procs))
 	}
 
+	values, err := common.DoSysctrl("kern.hostuuid")
+	if err == nil && len(values) == 1 && values[0] != "" {
+		ret.HostID = values[0]
+	}
+
 	return ret, nil
 }
 
diff --git a/host/host_linux.go b/host/host_linux.go
index 3d73242..a9f3749 100644
--- a/host/host_linux.go
+++ b/host/host_linux.go
@@ -61,6 +61,11 @@ func Info() (*InfoStat, error) {
 		ret.Procs = numProcs
 	}
 
+	values, err := common.DoSysctrl("kernel.random.boot_id")
+	if err == nil && len(values) == 1 && values[0] != "" {
+		ret.HostID = values[0]
+	}
+
 	return ret, nil
 }
 
diff --git a/host/host_test.go b/host/host_test.go
index d73d187..18832ab 100644
--- a/host/host_test.go
+++ b/host/host_test.go
@@ -66,8 +66,9 @@ func TestHostInfoStat_String(t *testing.T) {
 		OS:       "linux",
 		Platform: "ubuntu",
 		BootTime: 1447040000,
+		HostID:   "edfd25ff-3c9c-b1a4-e660-bd826495ad35",
 	}
-	e := `{"hostname":"test","uptime":3000,"bootTime":1447040000,"procs":100,"os":"linux","platform":"ubuntu","platformFamily":"","platformVersion":"","virtualizationSystem":"","virtualizationRole":""}`
+	e := `{"hostname":"test","uptime":3000,"bootTime":1447040000,"procs":100,"os":"linux","platform":"ubuntu","platformFamily":"","platformVersion":"","virtualizationSystem":"","virtualizationRole":"","hostid":"edfd25ff-3c9c-b1a4-e660-bd826495ad35"}`
 	if e != fmt.Sprintf("%v", v) {
 		t.Errorf("HostInfoStat string is invalid: %v", v)
 	}