Create usbip_systemd_monitor.sh

usbip_systemd_monitor.sh

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+#!/bin/bash
+
+# Enancement for https://github.com/psct/usbip
+# This utility expects the systemd dynamic unit files
+# provided at https://github.com/psct/usbip
+#
+# Issue/Problem to solve:
+# When the usbipd server is rebooted;
+# When the USB device at usbipd server is removed (and re-inserted)
+# The binding by uspip client with the server USB device gets disconnected
+# The binding does not auto recover
+#
+# This utility will ONLY restore the binding for
+# dynamic unit files which have been started
+# Unit files which have not been enabled/started, will be ignored
+#
+# dynamic unit file example:
+#   usbip@pi4:0403:6001.service
+#
+# USAGE:
+#  Call this script on a regular basis, eg from a cron.d job (every minute)
+#  /etc/cron.d/uspib_monitor:
+#  PATH=/bin:/usr/bin:/sbin:/usr/sbin !!IMPORTANT, add in cron.d file!!
+#  * * * * * root /<path to script>/usbip_systemd_monitor
+
+scriptname=`basename "$0"`
+logger -t ${scriptname} "START ${scriptname[$BASHPID]} PID = $BASHPID"
+
+# Find all dynamic unit files with pattern like
+# usbip@usbipdserver:2341:8036.service
+# and store in serviceArray
+# Ignore duplicates
+# systemctl --no-pager --type=service --state=failed | grep usbip@
+# systemctl --no-pager --type=service --state=active | grep usbip@
+
+# counter for array
+arrayindex=0
+
+# Store retrieved info on unit files in 3 different arrays:
+# 1. servicesArray: Full name of dynamic unit file, e.g. "usbip@pi4:0403:6001.service"
+# 2. deviceID: USB device id, e.g. "0403:6001"
+# 3. usbipdServer, e.g. "pi4"
+
+
+# Query usbip@ unit files, based on state failed, active and exited
+systemctlOutput=$(systemctl --no-pager --type=service --state=failed | grep usbip@)
+for str in ${systemctlOutput[@]}; do
+
+  # With regex and BASH_REMATCH, find dynamic unit filename, deviceID and usbipdServer
+  if [[ "${str}" =~ ^usbip@(.*):(.*:.*)\.service$ ]]; then
+
+    # Already store deviceID and usbipdServer, as
+    # BASH_REMATCH will lose content after duplicate check
+    # In case it is a duplicate, results are omitted
+    # As servicesArray is leading
+    deviceID[${arrayindex}]=${BASH_REMATCH[2]}
+    usbipdServer[${arrayindex}]=${BASH_REMATCH[1]}
+
+    # Check if unit file is already in array; if so, skip
+    if [[ "${servicesArray[*]}" =~ "${str}" ]]; then
+      continue
+    fi
+
+    servicesArray[${arrayindex}]=${str}
+    (( arrayindex++ ))
+  fi
+done
+
+systemctlOutput=$(systemctl --no-pager --type=service --state=active | grep usbip@)
+for str in ${systemctlOutput[@]}; do
+  if [[ "${str}" =~ ^usbip@(.*):(.*:.*)\.service$ ]]; then
+
+    # Already store deviceID and usbipdServer, as
+    # BASH_REMATCH will lose content after duplicate check
+    # In case it is a duplicate, results are omitted
+    # As servicesArray is leading
+    deviceID[${arrayindex}]=${BASH_REMATCH[2]}
+    usbipdServer[${arrayindex}]=${BASH_REMATCH[1]}
+
+    # Check if unit file is already in array; if so, skip
+    if [[ "${servicesArray[*]}" =~ "${str}" ]]; then
+      continue
+    fi
+
+    servicesArray[${arrayindex}]=${str}
+    (( arrayindex++ ))
+  fi
+done
+
+systemctlOutput=$(systemctl --no-pager --type=service --state=exited | grep usbip@)
+for str in ${systemctlOutput[@]}; do
+  if [[ "${str}" =~ ^usbip@(.*):(.*:.*)\.service$ ]]; then
+
+    # Already store deviceID and usbipdServer, as
+    # BASH_REMATCH will lose content after duplicate check
+    # In case it is a duplicate, results are omitted
+    # As servicesArray is leading
+    deviceID[${arrayindex}]=${BASH_REMATCH[2]}
+    usbipdServer[${arrayindex}]=${BASH_REMATCH[1]}
+
+    # Check if unit file is already in array; if so, skip
+    if [[ "${servicesArray[*]}" =~ "${str}" ]]; then
+      continue
+    fi
+
+    servicesArray[${arrayindex}]=${str}
+    (( arrayindex++ ))
+  fi
+done
+
+arrayLength=${#servicesArray[@]}
+
+# print dynamic unit files found
+for (( i=0; i<${arrayLength}; i++ )); do
+  logger -t ${scriptname} "Found dynamic unitfile: ${servicesArray[${i}]}; deviceID: ${deviceID[${i}]}; server: ${usbipdServer[${i}]}"
+done
+
+# Actual checking if unit file is active and usb available for binding
+for (( i=0; i<${arrayLength}; i++ )); do
+  logger -t ${scriptname} "Check unit file: ${servicesArray[${i}]}........"
+
+  # Check if unit file is active (if not, we will skip)
+  systemctl is-active --quiet ${servicesArray[${i}]}
+
+  if [ "$?" -eq "0" ]; then
+    logger -t ${scriptname} "${servicesArray[${i}]} STARTED";
+
+    # Check if USB device is available for binding
+    # This means that server is back; or USB has been re-inserted
+    deviceavailable=$(usbip list -r ${usbipdServer[${i}]} | grep "${deviceID[${i}]}" | wc -l)
+    logger -t ${scriptname} "deviceavailable: ${deviceavailable}"
+
+    if [ "${deviceavailable}" -eq "1" ]; then
+      logger -t ${scriptname} "Remote USB device available for binding....restart unit file ${servicesArray[${i}]}"
+      systemctl restart ${servicesArray[${i}]}
+    else
+      logger -t ${scriptname} "No remote USB device available for binding OR device is already binded"
+    fi
+
+  else
+    logger -t ${scriptname} "${servicesArray[${i}]} STOPPED";
+    logger -t ${scriptname} "No further checking..."
+  fi
+
+done
+
+logger -t ${scriptname} "EXIT ${scriptname[$BASHPID]} PID = $BASHPID"
+exit 0;