From a7fae95682e391a60abbbd233b04229fa59e2d08 Mon Sep 17 00:00:00 2001
From: Ted Unangst <tedu@tedunangst.com>
Date: Fri, 8 Nov 2019 19:11:37 -0500
Subject: [PATCH] add sensors to the about page

---
 sensors.go       | 43 +++++++++++++++++++++++++++++++++++++++++++
 views/about.html |  6 +++++-
 web.go           |  3 +++
 3 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 sensors.go

diff --git a/sensors.go b/sensors.go
new file mode 100644
index 0000000..c5fef02
--- /dev/null
+++ b/sensors.go
@@ -0,0 +1,43 @@
+//
+// Copyright (c) 2019 Ted Unangst <tedu@tedunangst.com>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+package main
+
+import (
+	"syscall"
+	"time"
+)
+
+type Sensors struct {
+	Memory float64
+	Uptime float64
+	CPU    float64
+}
+
+var boottime = time.Now()
+
+func getSensors() Sensors {
+	var usage syscall.Rusage
+	syscall.Getrusage(syscall.RUSAGE_SELF, &usage)
+
+	now := time.Now()
+
+	var sensors Sensors
+	sensors.Memory = float64(usage.Maxrss) / 1024.0
+	sensors.Uptime = now.Sub(boottime).Seconds()
+	sensors.CPU = time.Duration(usage.Utime.Nano()).Seconds()
+
+	return sensors
+}
diff --git a/views/about.html b/views/about.html
index 037620e..3ed58a0 100644
--- a/views/about.html
+++ b/views/about.html
@@ -2,6 +2,10 @@
 <main>
 <div class="info">
 {{ .AboutMsg }}
-<p style="text-align:right"><small>version: {{ .HonkVersion }}</small>
+<p><small>version: {{ .HonkVersion }}
+<br>memory: {{ printf "%.02f" .Sensors.Memory }}MB
+<br>uptime: {{ printf "%.02f" .Sensors.Uptime }}s
+<br>cputime: {{ printf "%.02f" .Sensors.CPU }}s
+</small>
 </div>
 </main>
diff --git a/web.go b/web.go
index aa91e1e..4545c6c 100644
--- a/web.go
+++ b/web.go
@@ -1902,6 +1902,9 @@ func servehtml(w http.ResponseWriter, r *http.Request) {
 	templinfo["AboutMsg"] = aboutMsg
 	templinfo["LoginMsg"] = loginMsg
 	templinfo["HonkVersion"] = honkVersion
+	if r.URL.Path == "/about" {
+		templinfo["Sensors"] = getSensors()
+	}
 	if u == nil {
 		w.Header().Set("Cache-Control", "max-age=60")
 	}