Add async checking for updates for improved performance

dockcheck.sh

@@ -34,6 +34,7 @@ Help() {
   echo "-s     Include stopped containers in the check. (Logic: docker ps -a)."
   echo "-t     Set a timeout (in seconds) per container for registry checkups, 10 is default."
   echo "-v     Prints current version."
+  echo "-z     [Experimental] Check images asynchrously for increased performance."
   echo
   echo "Project source: $Github"
 }
@@ -48,7 +49,7 @@ c_reset="\033[0m"
 
 Timeout=10
 Stopped=""
-while getopts "aynpfrhlisvmc:e:d:t:" options; do
+while getopts "aynpfrhlisvmzc:e:d:t:" options; do
   case "${options}" in
     a|y) AutoUp="yes" ;;
     c)   CollectorTextFileDirectory="${OPTARG}"
@@ -64,6 +65,7 @@ while getopts "aynpfrhlisvmc:e:d:t:" options; do
     s)   Stopped="-a" ;;
     t)   Timeout="${OPTARG}" ;;
     v)   printf "%s\n" "$VERSION" ; exit 0 ;;
+    z)   ParallelCheck=1 ;;
     d)   DaysOld=${OPTARG}
          if ! [[ $DaysOld =~ ^[0-9]+$ ]] ; then { printf "Days -d argument given (%s) is not a number.\n" "${DaysOld}" ; exit 2 ; } ; fi ;;
     h|*) Help ; exit 2 ;;
@@ -282,8 +284,9 @@ if [[ $t_out ]]; then
 else t_out=""
 fi
 
-# Check the image-hash of every running container VS the registry
+if [[ $ParallelCheck -ne 1 ]]; then
-for i in $(docker ps $Stopped --filter "name=$SearchName" --format '{{.Names}}') ; do
+  # Check the image-hash of every running container VS the registry
+  for i in $(docker ps $Stopped --filter "name=$SearchName" --format '{{.Names}}') ; do
     ((RegCheckQue+=1))
     progress_bar "$RegCheckQue" "$ContCount"
     # Looping every item over the list of excluded names and skipping
@@ -306,7 +309,65 @@ for i in $(docker ps $Stopped --filter "name=$SearchName" --format '{{.Names}}')
       # Here the RegHash is the result of an error code
       GotErrors+=("$i - ${RegHash}")
     fi
-done
+  done
+else
+  check_image() {
+    i="$1"
+    local Excludes=($Excludes_string)
+    local skip
+    for e in "${Excludes[@]}" ; do [[ "$i" == "$e" ]] && skip=1 ; done
+
+    if [[ $skip -eq 1 ]]; then
+      echo Skip $i
+      return
+    fi
+
+    local NoUpdates GotUpdates GotErrors
+    ImageId=$(docker inspect "$i" --format='{{.Image}}')
+    RepoUrl=$(docker inspect "$i" --format='{{.Config.Image}}')
+    LocalHash=$(docker image inspect "$ImageId" --format '{{.RepoDigests}}')
+
+    # Checking for errors while setting the variable
+    if RegHash=$(${t_out} $regbin -v error image digest --list "$RepoUrl" 2>&1) ; then
+      if [[ "$LocalHash" = *"$RegHash"* ]] ; then
+        echo NoUpdates "$i"
+      else
+        if [[ -n "$DaysOld" ]] && ! datecheck ; then
+          echo NoUpdates "+$i ${ImageAge}d"
+        else
+          echo GotUpdates "$i"
+        fi
+      fi
+    else
+      # Here the RegHash is the result of an error code
+      echo GotErrors "$i - ${RegHash}"
+    fi
+  }
+
+  export -f check_image datecheck
+  export Excludes_string="${Excludes[@]}" # Can only export scalar variables
+  export t_out regbin RepoUrl
+
+  # Asynchronously check the image-hash of every running container VS the registry
+  while read -r line; do
+    ((RegCheckQue+=1))
+    progress_bar "$RegCheckQue" "$ContCount"
+
+    Got=${line%% *}  # Extracts the first word (NoUpdates, GotUpdates, GotErrors)
+    item=${line#* }
+
+    case "$Got" in
+      NoUpdates) NoUpdates+=("$item") ;;
+      GotUpdates) GotUpdates+=("$item") ;;
+      GotErrors) GotErrors+=("$item") ;;
+      Skip) ;;
+      *) ;;
+    esac
+  done < <( \
+    docker ps $Stopped --filter "name=$SearchName" --format '{{.Names}}' | \
+    xargs -P 8 -I {} bash -c 'check_image "{}"' \
+  )
+fi
 
 # Sort arrays alphabetically
 IFS=$'\n'