From f35189442f37d158d9f13df7a750ab4825917053 Mon Sep 17 00:00:00 2001
From: "Hahn Axel (hahn)" <axel.hahn@iml.unibe.ch>
Date: Fri, 5 Nov 2021 17:01:56 +0100
Subject: [PATCH] add check_conn - check tcp and udp connections

---
 check_conn          | 148 ++++++++++++++++++++++++++++++++++++++++++++
 check_conn.cfg.dist |  19 ++++++
 2 files changed, 167 insertions(+)
 create mode 100755 check_conn
 create mode 100644 check_conn.cfg.dist

diff --git a/check_conn b/check_conn
new file mode 100755
index 0000000..0e90305
--- /dev/null
+++ b/check_conn
@@ -0,0 +1,148 @@
+#!/usr/bin/env bash
+# ======================================================================
+#
+# Check connection ... is a host available on a given port via tcp or udp
+#
+# requirements:
+# - none
+#
+# ----------------------------------------------------------------------
+# 2021-11-05  v0.0  <axel.hahn@iml.unibe.ch>
+# ======================================================================
+
+
+. `dirname $0`/inc_pluginfunctions
+
+cfgfile=$( dirname $0 )/$( basename $0 ).cfg
+
+
+out=""
+
+# ----------------------------------------------------------------------
+# functions
+# ----------------------------------------------------------------------
+
+function getChecks(){
+  while [ $# -gt 0 ]; do
+    test -r "$1" && grep -E "^(tcp|udp)/" "$1" 2>&1
+    shift 1
+  done
+}
+
+
+function showHelp(){
+cat <<EOF
+______________________________________________________________________
+
+CHECK_CONN check if is a host available on a given port via tcp or udp
+from local machine $( hostname -f ).
+
+(c) Institute for Medical Education - Univerity of Bern
+Licence: GNU GPL 3
+______________________________________________________________________
+
+
+SYNTAX:
+`basename $0` OPTIONS
+
+You can create a file named $cfgfile
+and add your connections there. 
+To start you can copy the file $cfgfile.dist
+
+OPTIONS:
+
+    -h or --help   show this help.
+    -t CONNECTION  test given connection; This param ignores entries
+                   in the config file. For multiple connection tests
+                   quote the parameter value and set spaces between
+                   the connections.
+
+PARAMETERS:
+
+    CONNECTION     Connection in the same syntax like in the config:
+                   tcp/host/port
+                   udp/host/port
+EXAMPLES:
+
+`basename $0`         If no param is given it checks entries in $cfgfile
+
+`basename $0` -t "tcp/api.example.com/443"
+                   Check a single connection
+
+`basename $0` -t "tcp/api.example.com/443 tcp/localhost/3306"
+                   Check multiple connections.
+
+EOF
+}
+# ----------------------------------------------------------------------
+# MAIN
+# ----------------------------------------------------------------------
+
+# --- check required tools
+# ph.require bc top
+
+
+# --- check param -h
+case "$1" in
+    "--help"|"-h")
+        showHelp
+        exit 0
+        ;;
+    *)
+esac
+
+configline=$( ph.getValueWithParam "" t "$@" )
+
+test -z "$configline" || cfgfile=""
+
+
+
+typeset -i iWarnings=0
+typeset -i iErrors=0
+typeset -i iOK=0
+typeset -i iCount=0
+
+for myline in $( echo $configline; getChecks $cfgfile )
+do
+
+  iCount=$iCount+1
+  
+  out="$out
+$myline"
+
+  # --- syntax check of config entry
+  echo "$myline" | grep -E "^(tcp|udp)/[a-z][a-z0-9\.\-]*/[0-9]*$" >/dev/null 2>&1
+  if [ $? -ne 0 ]; then
+    out="$out SKIP: INVALID ENTRY"
+    iWarnings=$iWarnings+1
+  else 
+    >/dev/$myline
+    if [ $? -ne 0 ]; then
+        out="$out FAILED"
+        iErrors=$iErrors+1
+    else
+        out="$out OK"
+        iOK=$iOK+1
+    fi
+  fi
+done
+
+# ----- output
+if [ $iCount -eq 0 ]; then
+ph.setStatus "unknown"
+ph.status "tcp check - NO checks"
+test $iCount    -eq 0 && echo "
+No config entry was found. Create a file named $cfgfile
+and add your connections i.e.
+tcp/www.example.com/443"
+else
+    test $iWarnings -gt 0 && ph.setStatus "warning"
+    test $iErrors   -gt 0 && ph.setStatus "critical"
+    ph.status "tcp check - $iCount checks - $iOK OK; $iWarnings warnings; $iErrors errors $out"
+fi
+
+# ----- CLEANUP AND BYE!
+
+ph.exit
+
+# ----------------------------------------------------------------------
diff --git a/check_conn.cfg.dist b/check_conn.cfg.dist
new file mode 100644
index 0000000..2f1aa58
--- /dev/null
+++ b/check_conn.cfg.dist
@@ -0,0 +1,19 @@
+# ----------------------------------------------------------------------
+#
+# This is an example file for check_tcp
+# You need to rename it and then make your changes.
+#
+# lines not starting with tcp or udp will be ignored. So feel free
+# to use # or ; as commented lines or add empty lines for spacing.
+#
+# ----------------------------------------------------------------------
+
+
+# check if a needed api server is reachable
+tcp/api.example.com/80
+tcp/api.example.com/443
+
+# check local mysql port
+tcp/localhost/3306
+
+# ----------------------------------------------------------------------
-- 
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