From 31361b44e5d079ab7e968a2ac86faefb5d42bdc1 Mon Sep 17 00:00:00 2001
From: Markus Valentin <markus.valentin@open-xchange.com>
Date: Wed, 19 Jun 2019 16:29:49 +0200
Subject: [PATCH] script: health-check: add health-check.sh default script

As a example for an simple tcp health check the health-check.sh script
is added. It closes the connection after 10 seconds and only answer to
"PING\n" with a "PONG\n". It is installed by default next to the script
executable.
---
 src/util/Makefile.am             |  6 +++++-
 src/util/health-check-settings.c | 31 +++++++++++++++++++++++++++++++
 src/util/health-check.sh         | 26 ++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 src/util/health-check-settings.c
 create mode 100755 src/util/health-check.sh

diff --git a/src/util/Makefile.am b/src/util/Makefile.am
index e1b522a1ec..3e1dd8ff3b 100644
--- a/src/util/Makefile.am
+++ b/src/util/Makefile.am
@@ -45,7 +45,8 @@ script_LDADD = $(LIBDOVECOT) \
 	$(BINARY_LDFLAGS)
 script_DEPENDENCIES = $(LIBDOVECOT_DEPS)
 script_SOURCES = \
-	script.c
+	script.c \
+	health-check-settings.c
 
 if TCPWRAPPERS
 TCPWRAP_BIN = tcpwrap
@@ -71,3 +72,6 @@ maildirlock_LDADD = $(LIBDOVECOT) \
 maildirlock_DEPENDENCIES = $(LIBDOVECOT_DEPS)
 maildirlock_SOURCES = \
 	maildirlock.c
+
+pkglibexec_SCRIPTS = health-check.sh
+EXTRA_DIST = $(pkglibexec_SCRIPTS)
diff --git a/src/util/health-check-settings.c b/src/util/health-check-settings.c
new file mode 100644
index 0000000000..f6732719bb
--- /dev/null
+++ b/src/util/health-check-settings.c
@@ -0,0 +1,31 @@
+/* Copyright (c) 2019 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "buffer.h"
+#include "settings-parser.h"
+#include "service-settings.h"
+
+struct service_settings health_check_service_settings = {
+	.name = "health-check",
+	.protocol = "",
+	.type = "",
+	.executable = "script -p health-check.sh",
+	.user = "$default_internal_user",
+	.group = "",
+	.privileged_group = "",
+	.extra_groups = "",
+	.chroot = "",
+
+	.drop_priv_before_exec = TRUE,
+
+	.process_min_avail = 0,
+	.process_limit = 0,
+	.client_limit = 1,
+	.service_count = 0,
+	.idle_kill = 0,
+	.vsz_limit = (uoff_t)-1,
+
+	.unix_listeners = ARRAY_INIT,
+	.fifo_listeners = ARRAY_INIT,
+	.inet_listeners = ARRAY_INIT
+};
diff --git a/src/util/health-check.sh b/src/util/health-check.sh
new file mode 100755
index 0000000000..119990fb42
--- /dev/null
+++ b/src/util/health-check.sh
@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) 2019 Dovecot authors, see the included COPYING file */
+#
+# This script is intended to be called by the script service and to be
+# connected to a socket using a service configuration like this:
+# 	executable = script -p /path/to/health-check.sh
+#
+# This simple example merely answers "PONG\n" if the input is "PING\n". It
+# stops waiting for input after $TIMEOUT which causes the process to die
+# which causes the script module to close the socket. Inputs and outputs
+# can be written to STDIN and STDOUT, they are duplicated file-descriptors
+# if called from the script service.
+
+TIMEOUT=10
+
+read -t ${TIMEOUT} -r input
+
+exit_code=$?
+cleaned_input=${input//[^a-zA-Z0-9]/}
+
+if [ $exit_code -eq 0 ] && [ "$cleaned_input" = "PING" ];then
+	echo "PONG"
+fi
+# always exit successful
+exit 0
-- 
2.47.3