From c6fd6907129d69b3f0d96cd1b57147dcfe65a74b Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonygarnockjones@gmail.com>
Date: Fri, 1 Jun 2018 18:40:43 +0100
Subject: [PATCH] ping-service.sh

---
 ping-service.sh | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100755 ping-service.sh

diff --git a/ping-service.sh b/ping-service.sh
new file mode 100755
index 0000000..e79842e
--- /dev/null
+++ b/ping-service.sh
@@ -0,0 +1,32 @@
+#!/bin/bash
+#
+# I am a script, intended to run from `cron`, which pings a
+# configurable URL, and if no suitable response is forthcoming,
+# performs a configurable command.
+#
+# For example, to monitor racket-pkg-website, try
+#
+# ./ping-service.sh https://localhost:8444/ping 'touch .../signals/.dumpinfo; svc -du ...'
+
+if [ "$#" != "2" ]
+then
+    echo 'Usage: ping-service.sh <url> <command>'
+    echo 'Note that <command> has to be a single string.'
+    exit 1
+fi
+
+url="$1"
+failurecommand="$2"
+
+# curl flags:
+#  -f == fail, interrogate the HTTP response status code
+#  -s == silent, don't print a progress meter or any other cruft
+#  -k == Ignore certificates, where url is an HTTPS URL
+#
+if curl -f -s -k --max-time 10 "$url" > /dev/null
+then
+    # Do nothing -- the retrieval was successful
+    true
+else
+    exec sh -c "$failurecommand"
+fi