From 6f25a30634fee48be929b5dd96252fe364cdedc9 Mon Sep 17 00:00:00 2001
From: Klaus Sperner <klaus.sperner@gmail.com>
Date: Fri, 5 Feb 2021 12:55:24 +0100
Subject: [PATCH 1/4] Add multigraph plugin for http response codes and times

In contrast to using http_responsecode and http_loadtime with the same
configuration, this plugin performs only one request per site and munin
run to gather its statistics.
---
 plugins/http/http_response | 198 +++++++++++++++++++++++++++++++++++++
 1 file changed, 198 insertions(+)
 create mode 100644 plugins/http/http_response

diff --git a/plugins/http/http_response b/plugins/http/http_response
new file mode 100644
index 000000000..63a35e209
--- /dev/null
+++ b/plugins/http/http_response
@@ -0,0 +1,198 @@
+#!/usr/bin/env bash
+# vim: expandtab:ts=4:sw=4
+
+: << =cut
+
+=head1 NAME
+
+http_response - Monitor HTTP response statistics
+
+=head1 CONFIGURATION
+
+The following environment variables are used
+
+ sites       - Sites to check
+                 - separated by spaces
+                 - can contain basic auth credentials
+                 - defaults to "http://localhost/"
+ max_time    - Timeout for each site check in seconds
+                 - defaults to 5 seconds
+ short_label - Switch for shortening the label below the graph
+                 - defaults to false
+
+=head2 CONFIGURATION EXAMPLE
+
+ [http_response]
+  env.sites http://example.com/ https://user:secret@example2.de
+  env.max_time 20
+  env.short_label true
+
+=head1 PREREQUISITES
+
+This plugin needs at least bash version 4 to run
+
+=head1 NOTES
+
+This plugin unifies the functionalities of the following plugins into one
+multigraph plugin
+
+ http_loadtime     - https://gallery.munin-monitoring.org/plugins/munin/http_loadtime/
+ http_responsecode - https://gallery.munin-monitoring.org/plugins/munin-contrib/http_responsecode/
+
+In contrast to using these two plugins with the same configuration, this plugin
+performs only one request per site and munin run to gather its statistics.
+
+=head1 AUTHOR
+
+Copyright (C) 2020 Klaus Sperner
+
+=head1 LICENSE
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; version 2 dated June,
+1991.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+=head1 MAGIC MARKERS
+
+ #%# family=manual
+
+=cut
+
+. "$MUNIN_LIBDIR/plugins/plugin.sh"
+
+readonly uri_regex='^(https?://)([^:]*):(.*)@(.*)$'
+
+strip_credentials_from_url() {
+    if [[ "$1" =~ $uri_regex ]]; then
+        echo "${BASH_REMATCH[1]}${BASH_REMATCH[4]}"
+    else
+        echo "$1"
+    fi
+}
+
+extract_username_from_url() {
+    if [[ "$1" =~ $uri_regex ]]; then
+        echo "${BASH_REMATCH[2]}"
+    else
+        echo ""
+    fi
+}
+
+extract_password_from_url() {
+    if [[ "$1" =~ $uri_regex ]]; then
+        echo "${BASH_REMATCH[3]}"
+    else
+        echo ""
+    fi
+}
+
+compute_label() {
+    if [[ "${short_label,,}" == "true" || "${short_label,,}" == "yes" ]]; then
+        if [[ ${#1} -gt 33 ]]; then
+            echo "${1:0:30}..."
+        else
+            echo "$1"
+        fi
+    else
+        echo "$1"
+    fi
+}
+
+if [[ "${BASH_VERSINFO:-0}" -lt 4 ]]; then
+    >&2 echo "The plugin http_response needs at least bash version 4"
+    exit 1
+fi
+
+sites=${sites:-"http://localhost/"}
+max_time=${max_time:-5}
+short_label=${short_label:-"false"}
+
+if [[ "$1" == "config" ]]; then
+    echo 'multigraph http_response_code'
+    echo 'graph_args --base 1000 -l 0 -u 511'
+    echo 'graph_title HTTP Response Codes'
+    echo 'graph_vlabel Repsonse Code'
+    echo 'graph_category network'
+    echo 'graph_info This graph shows HTTP response code statistics'
+    echo 'graph_printf %3.0lf'
+    for site in $sites; do
+        site_without_credentials=$( strip_credentials_from_url "$site" )
+        siteid="$( clean_fieldname "$site_without_credentials" )"
+        echo "$siteid.label $( compute_label "$site_without_credentials" )"
+        echo "$siteid.info HTTP response code statistics for $site_without_credentials"
+        echo "$siteid.critical 99:399";
+    done
+    echo 'multigraph http_response_time'
+    echo 'graph_args --base 1000 -l 0'
+    echo 'graph_title HTTP Response Times'
+    echo 'graph_vlabel Response Time in seconds'
+    echo 'graph_category network'
+    echo 'graph_info This graph shows HTTP response time statistics'
+    for site in $sites; do
+        site_without_credentials=$( strip_credentials_from_url "$site" )
+        siteid="$( clean_fieldname "$site_without_credentials" )"
+        echo "$siteid.label $( compute_label "$site_without_credentials" )"
+        echo "$siteid.info HTTP response time statistics for $site_without_credentials"
+    done
+    exit 0
+fi
+
+declare -A response_codes
+declare -A response_times
+
+for site in $sites; do
+    site_without_credentials=$( strip_credentials_from_url "$site" )
+    username=$( extract_username_from_url "$site" )
+    password=$( extract_password_from_url "$site" )
+
+    curl_config_file=""
+    curl_auth_opt=()
+    if [ -n "$username" ]; then
+        if [ -z "$password" ]; then
+            >&2 echo "Invalid configuration: username specified without password"
+            exit 1
+        fi
+        curl_config_file=$(mktemp) || exit 1
+        trap 'rm -f "$curl_config_file"' EXIT
+        echo "user=${username}:${password}" >> "$curl_config_file"
+        curl_auth_opt=(--config "$curl_config_file")
+    fi
+
+    siteid="$( clean_fieldname "$site_without_credentials" )"
+    statuscode=
+    loadtime=
+    start=$(date +%s.%N)
+    statuscode=$( curl "${curl_auth_opt[@]}" --write-out '%{http_code}' --max-time "$max_time" --silent --output /dev/null "$site_without_credentials" )
+    returncode=$?
+    loadtime=$( echo "$start" "$(date +%s.%N)" | awk '{ print($2 - $1); }' )
+    if [[ $returncode -ne 0 ]]; then
+        loadtime=0
+    fi
+    response_codes+=(["$siteid"]="$statuscode")
+    response_times+=(["$siteid"]="$loadtime")
+
+    if [ -n "$curl_config_file" ]; then
+        rm -f "$curl_config_file"
+    fi
+done
+
+echo 'multigraph http_response_code'
+for siteid in "${!response_codes[@]}"; do
+    echo "${siteid}.value ${response_codes[${siteid}]}"
+done
+
+echo 'multigraph http_response_time'
+for siteid in "${!response_times[@]}"; do
+    echo "${siteid}.value ${response_times[${siteid}]}"
+done
+

From 3fba496092d1b5553e16deee1ab060857cebb7e7 Mon Sep 17 00:00:00 2001
From: Klaus Sperner <klaus.sperner@gmail.com>
Date: Fri, 5 Feb 2021 13:23:03 +0100
Subject: [PATCH 2/4] make plugin http_response executable

---
 plugins/http/http_response | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 mode change 100644 => 100755 plugins/http/http_response

diff --git a/plugins/http/http_response b/plugins/http/http_response
old mode 100644
new mode 100755

From 64693362352c64a9f73e7c47c15815f4af189bb1 Mon Sep 17 00:00:00 2001
From: Klaus Sperner <klaus.sperner@gmail.com>
Date: Fri, 17 Sep 2021 16:43:35 +0200
Subject: [PATCH 3/4] add plugin tcp_reachability

---
 plugins/network/tcp_reachability | 261 +++++++++++++++++++++++++++++++
 1 file changed, 261 insertions(+)
 create mode 100755 plugins/network/tcp_reachability

diff --git a/plugins/network/tcp_reachability b/plugins/network/tcp_reachability
new file mode 100755
index 000000000..f35b1a5cb
--- /dev/null
+++ b/plugins/network/tcp_reachability
@@ -0,0 +1,261 @@
+#!/usr/bin/env bash
+# vim: expandtab:ts=4:sw=4
+
+: << =cut
+
+=head1 NAME
+
+tcp_reachability - Test if a (remote) TCP port is reachable and monitor
+connection time statistics
+
+=head1 CONFIGURATION
+
+The following environment variables are used:
+
+=over
+
+=item *
+
+targets - The targets to test
+
+=over
+
+=item *
+
+separated by spaces
+
+=item *
+
+each target must be in the form C<host/port>
+
+=item *
+
+host can be an IP address or a DNS name
+
+=item *
+
+port can be a port number or a service name
+
+=item *
+
+defaults to C<localhost/22>
+
+=back
+
+=item *
+
+max_time - Timeout for each target check in seconds
+
+=over
+
+=item *
+
+defaults to C<2>
+
+=back
+
+=item *
+
+short_label - Switch for shortening the label below the graph
+
+=over
+
+=item *
+
+defaults to C<false>
+
+=back
+
+=back
+
+This plugin does not need any specific privileges and can be run as a totally
+unprivileged user like nobody.
+
+=head2 CONFIGURATION EXAMPLE
+
+ [tcp_reachability]
+  env.targets 10.19.23.42/5432 munin-monitoring.org/https
+  env.max_time 5
+  env.short_label true
+
+=head1 PREREQUISITES
+
+This plugin needs at least bash version 4 to run.
+
+Additionally the following basic programs must be present on your system:
+
+=over
+
+=item *
+
+awk
+
+=item *
+
+date
+
+=item *
+
+echo
+
+=item *
+
+timeout
+
+=back
+
+=head1 SEE ALSO
+
+There are a couple of ping plugins in
+L<https://github.com/munin-monitoring/contrib/tree/master/plugins/ping>. Many
+of these require additional software to be installed. The plugin
+L<multi_tcp_ping|https://gallery.munin-monitoring.org/plugins/munin-contrib/multi_tcp_ping/>
+provides timing statistics similar to this plugin.
+
+=head1 AUTHOR
+
+Copyright (C) 2021 Klaus Sperner
+
+=head1 LICENSE
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; version 2 dated June,
+1991.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+=head1 MAGIC MARKERS
+
+ #%# family=manual
+
+=cut
+
+# shellcheck disable=SC1091
+. "$MUNIN_LIBDIR/plugins/plugin.sh"
+
+# Basic regex for checking that "host/port" contains allowed characters only.
+# We don't check for RFC compliance of IP addresses, DNS names or service names
+# here.
+readonly host_port_regex='^[a-zA-Z0-9\.:-]+/[a-zA-Z0-9-]+$'
+
+# If the target is an IP address and therefore starts with a number, the first
+# digit is converted to an underscore by clean_fieldname. This causes the
+# effect that two targets differing in the first digit only result in the same
+# cleaned fieldname. Therefore we prefix every target with the same character
+# before calling clean_fieldname, so different IP addresses will always result
+# in different fieldnames. The following example shows the problem and its
+# solution:
+#
+#  +------------------+------------------+--------------------+
+#  | host/port        | clean_fieldname  | my_clean_fieldname |
+#  +------------------+------------------+--------------------+
+#  | 10.19.23.42/5432 | _0_19_23_42_5432 | x10_19_23_42_5432  |
+#  | 20.19.23.42/5432 | _0_19_23_42_5432 | x20_19_23_42_5432  |
+#  +------------------+------------------+--------------------+
+#
+my_clean_fieldname() {
+    clean_fieldname "x$1"
+}
+
+compute_label() {
+    if [[ "${short_label,,}" == "true" || "${short_label,,}" == "yes" ]]; then
+        if [[ ${#1} -gt 33 ]]; then
+            echo "${1:0:30}..."
+        else
+            echo "$1"
+        fi
+    else
+        echo "$1"
+    fi
+}
+
+check_programs_installed() {
+    for program in "$@"; do
+        if ! hash "$program" 2>/dev/null; then
+            >&2 echo "The plugin tcp_reachability needs $program but it is not installed. Aborting."
+            exit 1
+        fi
+    done
+}
+
+if [[ "${BASH_VERSINFO:-0}" -lt 4 ]]; then
+    >&2 echo "The plugin tcp_reachability needs at least bash version 4. Aborting."
+    exit 1
+fi
+
+check_programs_installed awk date echo timeout
+
+targets=${targets:-"localhost/22"}
+max_time=${max_time:-2}
+short_label=${short_label:-"false"}
+
+for target in $targets; do
+    if [[ ! "$target" =~ $host_port_regex ]]; then
+        >&2 echo "Invalid configuration: target $target is not a valid 'host/port' combination"
+        exit 1
+    fi
+done
+
+if [[ "$1" == "config" ]]; then
+    echo 'multigraph tcp_reachability'
+    echo 'graph_args --base 1000 --lower-limit -0.25 --upper-limit 1.25 --rigid'
+    echo 'graph_title TCP Reachability Status'
+    echo 'graph_vlabel Reachability Status'
+    echo 'graph_category network'
+    echo 'graph_info This graph shows TCP reachability statuses'
+    echo 'graph_printf %1.0lf'
+    for target in $targets; do
+        targetId="$( my_clean_fieldname "$target" )"
+        echo "$targetId.label $( compute_label "$target" )"
+        echo "$targetId.info TCP reachability status for $target"
+        echo "$targetId.critical 1:"
+    done
+    echo 'multigraph tcp_connection_time'
+    echo 'graph_args --base 1000 -l 0'
+    echo 'graph_title TCP Connection Times'
+    echo 'graph_vlabel Connection Time in seconds'
+    echo 'graph_category network'
+    echo 'graph_info This graph shows TCP connection time statistics'
+    for target in $targets; do
+        targetId="$( my_clean_fieldname "$target" )"
+        echo "$targetId.label $( compute_label "$target" )"
+        echo "$targetId.info TCP connection time statistics for $target"
+    done
+    exit 0
+fi
+
+declare -A reachabilities
+declare -A connection_times
+
+for target in $targets; do
+    target_id="$( my_clean_fieldname "$target" )"
+    reachability=1
+    start=$(date +%s.%N)
+    timeout "$max_time" bash -c "(echo > /dev/tcp/${target}) &> /dev/null"
+    return_code=$?
+    connection_time=$( echo "$start" "$(date +%s.%N)" | awk '{ print($2 - $1); }' )
+    if [[ $return_code -ne 0 ]]; then
+        reachability=0
+        connection_time="U"
+    fi
+    reachabilities+=(["$target_id"]="$reachability")
+    connection_times+=(["$target_id"]="$connection_time")
+done
+
+echo 'multigraph tcp_reachability'
+for target_id in "${!reachabilities[@]}"; do
+    echo "${target_id}.value ${reachabilities[${target_id}]}"
+done
+
+echo 'multigraph tcp_connection_time'
+for target_id in "${!connection_times[@]}"; do
+    echo "${target_id}.value ${connection_times[${target_id}]}"
+done

From 73fcf8782bfce97771f0c0f85597c41231cee526 Mon Sep 17 00:00:00 2001
From: Klaus Sperner <klaus.sperner@gmail.com>
Date: Fri, 17 Sep 2021 17:22:02 +0200
Subject: [PATCH 4/4] improvements for tcp_reachability

- update documentation "See Also"
- unify error messages
- check max_time for validity
---
 plugins/network/tcp_reachability | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/plugins/network/tcp_reachability b/plugins/network/tcp_reachability
index f35b1a5cb..5aba3fe96 100755
--- a/plugins/network/tcp_reachability
+++ b/plugins/network/tcp_reachability
@@ -108,9 +108,10 @@ timeout
 
 There are a couple of ping plugins in
 L<https://github.com/munin-monitoring/contrib/tree/master/plugins/ping>. Many
-of these require additional software to be installed. The plugin
+of these perform ICMP pings. The plugin
 L<multi_tcp_ping|https://gallery.munin-monitoring.org/plugins/munin-contrib/multi_tcp_ping/>
-provides timing statistics similar to this plugin.
+tests TCP ports and provides timing statistics similar to this plugin, but it
+does not provide a reachability graph and it does not define any alarm limits.
 
 =head1 AUTHOR
 
@@ -199,11 +200,16 @@ short_label=${short_label:-"false"}
 
 for target in $targets; do
     if [[ ! "$target" =~ $host_port_regex ]]; then
-        >&2 echo "Invalid configuration: target $target is not a valid 'host/port' combination"
+        >&2 echo "Invalid configuration: target $target is not a valid 'host/port' combination. Aborting."
         exit 1
     fi
 done
 
+if [[ ! "$max_time" =~ ^[0-9]+$ ]]; then
+    >&2 echo "Invalid configuration: max_time $max_time must contain only digits. Aborting."
+    exit 1
+fi
+
 if [[ "$1" == "config" ]]; then
     echo 'multigraph tcp_reachability'
     echo 'graph_args --base 1000 --lower-limit -0.25 --upper-limit 1.25 --rigid'