moved the prune logic and made a forced prune with -k flag

dockcheck.sh

@@ -42,6 +42,7 @@ Help() {
   echo "-h     Print this Help."
   echo "-i     Inform - send a preconfigured notification."
   echo "-I     Prints custom releasenote urls alongside each container with updates in CLI output (requires urls.list)."
+  echo "-k N   Number of days to store image backups before pruning - this also enables the backup function."
   echo "-l     Only include containers with label set. See readme."
   echo "-m     Monochrome mode, no printf colour codes and hides progress bar."
   echo "-M     Prints custom releasenote urls as markdown (requires template support)."
@@ -77,6 +78,7 @@ Stopped=${Stopped:-""}
 CollectorTextFileDirectory=${CollectorTextFileDirectory:-}
 Exclude=${Exclude:-}
 DaysOld=${DaysOld:-}
+DaysKept=${DaysKept:-}
 OnlySpecific=${OnlySpecific:-false}
 SpecificContainer=${SpecificContainer:-""}
 SkipRecreate=${SkipRecreate:-false}
@@ -97,7 +99,11 @@ c_blue="\033[0;34m"
 c_teal="\033[0;36m"
 c_reset="\033[0m"
 
-while getopts "ayfFhiIlmMnprsuvc:e:d:t:x:R" options; do
+# Timestamps
+RunTimestamp=$(date +'%Y-%m-%d_%H%M')
+RunEpoch=$(date +'%s')
+
+while getopts "ayfFhiIlmMnprsuvc:e:d:k:t:x:R" options; do
   case "${options}" in
     a|y) AutoMode=true ;;
     c)   CollectorTextFileDirectory="${OPTARG}" ;;
@@ -107,6 +113,7 @@ while getopts "ayfFhiIlmMnprsuvc:e:d:t:x:R" options; do
     F)   OnlySpecific=true ;;
     i)   Notify=true ;;
     I)   PrintReleaseURL=true ;;
+    k)   DaysKept="${OPTARG}" ;;
     l)   OnlyLabel=true ;;
     m)   MonoMode=true ;;
     M)   PrintMarkdownURL=true ;;
@@ -156,6 +163,12 @@ if [[ -n "$DaysOld" ]]; then
     exit 2
   fi
 fi
+if [[ -n "$DaysKept" ]]; then
+  if ! [[ $DaysKept =~ ^[0-9]+$ ]]; then
+    printf "-k argument given (%s) is not a number.\n" "$DaysKept"
+    exit 2
+  fi
+fi
 if [[ -n "$CollectorTextFileDirectory" ]]; then
   if ! [[ -d  $CollectorTextFileDirectory ]]; then
     printf "The directory (%s) does not exist.\n" "$CollectorTextFileDirectory"
@@ -196,11 +209,11 @@ self_update() {
     printf "\n%s\n" "Pulling the latest version."
     git pull --force || { printf "%bGit error,%b manually pull/clone.\n" "$c_red" "$c_reset"; return; }
     printf "\n%s\n" "--- starting over with the updated version ---"
-    cd - || { printf "%bPath error.%b\n" "$c_red"; return; }
+    cd - || { printf "%bPath error.%b\n" "$c_red" "$c_reset"; return; }
     exec "$ScriptPath" "${ScriptArgs[@]}" # run the new script with old arguments
     exit 0 # exit the old instance
   else
-    cd - || { printf "%bPath error.%b\n" "$c_red"; return; }
+    cd - || { printf "%bPath error.%b\n" "$c_red" "$c_reset"; return; }
     self_update_curl
   fi
 }
@@ -228,10 +241,11 @@ choosecontainers() {
 }
 
 datecheck() {
-  ImageDate=$("$regbin" -v error image inspect "$RepoUrl" --format='{{.Created}}' | cut -d" " -f1)
+  ImageDate="$1"
+  DaysMax="$2"
   ImageEpoch=$(date -d "$ImageDate" +%s 2>/dev/null) || ImageEpoch=$(date -f "%Y-%m-%d" -j "$ImageDate" +%s)
-  ImageAge=$(( ( $(date +%s) - ImageEpoch )/86400 ))
-  if [[ "$ImageAge" -gt "$DaysOld" ]]; then
+  ImageAge=$(( ( RunEpoch - ImageEpoch )/86400 ))
+  if [[ "$ImageAge" -gt "$DaysMax" ]]; then
     return 0
   else
     return 1
@@ -358,7 +372,7 @@ list_options() {
 }
 
 # Version check & initiate self update
-if [[ "$LatestRelease" != "undefined" ]]; then
+if [[ "$LatestSnippet" != "undefined" ]]; then
   if [[ "$VERSION" != "$LatestRelease" ]]; then
     printf "New version available! %b%s%b ⇒ %b%s%b \n Change Notes: %s \n" "$c_yellow" "$VERSION" "$c_reset" "$c_green" "$LatestRelease" "$c_reset" "$LatestChanges"
     if [[ "$AutoMode" == false ]]; then
@@ -443,7 +457,7 @@ check_image() {
     if [[ "$LocalHash" == *"$RegHash"* ]]; then
       printf "%s\n" "NoUpdates $i"
     else
-      if [[ -n "${DaysOld:-}" ]] && ! datecheck; then
+      if [[ -n "${DaysOld:-}" ]] && ! datecheck $("$regbin" -v error image inspect "$RepoUrl" --format='{{.Created}}' | cut -d" " -f1) "$DaysOld" ; then
         printf "%s\n" "NoUpdates +$i ${ImageAge}d"
       else
         printf "%s\n" "GotUpdates $i"
@@ -540,11 +554,22 @@ if [[ -n "${GotUpdates:-}" ]]; then
     for i in "${SelectedUpdates[@]}"; do
       ((CurrentQue+=1))
       printf "\n%bNow updating (%s/%s): %b%s%b\n" "$c_teal" "$CurrentQue" "$NumberofUpdates" "$c_blue" "$i" "$c_reset"
-      ContLabels=$(docker inspect "$i" --format '{{json .Config.Labels}}')
-      ContImage=$(docker inspect "$i" --format='{{.Config.Image}}')
-      ContPath=$($jqbin -r '."com.docker.compose.project.working_dir"' <<< "$ContLabels")
+      ContConfig=$(docker inspect "$i" --format '{{json .}}')
+      ContImage=$($jqbin -r '."Config"."Image"' <<< "$ContConfig")
+      ImageId=$($jqbin -r '."Image"' <<< "$ContConfig")
+      ContPath=$($jqbin -r '."Config"."Labels"."com.docker.compose.project.working_dir"' <<< "$ContConfig")
       [[ "$ContPath" == "null" ]] && ContPath=""
 
+      # Add new backup tag prior to pulling if option is set
+      if [[ -n "${DaysKept:-}" ]]; then
+        ContRepo=${ContImage%:*}
+        ContApp=${ContRepo#*/}
+        [[ "$ContImage" =~ ":" ]] && ContTag=${ContImage#*:} || ContTag="latest"
+        BackupName="dockcheck/${ContApp}:${RunTimestamp}_${ContTag}"
+        docker tag "$ImageId" "$BackupName"
+        printf "%b%s backed up as %s%b\n" "$c_teal" "$i" "$BackupName" "$c_reset"
+      fi
+
       # Checking if compose-values are empty - hence started with docker run
       if [[ -z "$ContPath" ]]; then
         if [[ "$DRunUp" == true ]]; then
@@ -569,8 +594,8 @@ if [[ -n "${GotUpdates:-}" ]]; then
         ((CurrentQue+=1))
         unset CompleteConfs
         # Extract labels and metadata
-        ContLabels=$(docker inspect "$i" --format '{{json .Config.Labels}}')
-        ContImage=$(docker inspect "$i" --format='{{.Config.Image}}')
+        ContConfig=$(docker inspect "$i" --format '{{json .}}')
+        ContLabels=$($jqbin -r '."Config"."Labels"' <<< "$ContConfig")
         ContPath=$($jqbin -r '."com.docker.compose.project.working_dir"' <<< "$ContLabels")
         [[ "$ContPath" == "null" ]] && ContPath=""
         ContConfigFile=$($jqbin -r '."com.docker.compose.project.config_files"' <<< "$ContLabels")
@@ -610,14 +635,39 @@ if [[ -n "${GotUpdates:-}" ]]; then
         fi
       done
     fi
-    if [[ "$AutoPrune" == false ]] && [[ "$AutoMode" == false ]]; then printf "\n"; read -rep "Would you like to prune all dangling images? y/[n]: " AutoPrune; fi
-    if [[ "$AutoPrune" == true ]] || [[ "$AutoPrune" =~ [yY] ]]; then printf "\nAuto pruning.."; docker image prune -f; fi
-    printf "\n%bAll done!%b\n" "$c_green" "$c_reset"
+    printf "\n%bAll updates done!%b\n" "$c_green" "$c_reset"
+
+    # Clean up old backup image tags if -k is used
+    if [[ -n "${DaysKept:-}" ]]; then
+      IFS=$'\n'
+      CleanupCount=0
+      for backup_img in $(docker images --format "{{.Repository}} {{.Tag}}" | sed -n '/^dockcheck/p'); do
+        repo_name=${backup_img% *}
+        backup_tag=${backup_img#* }
+        backup_date=${backup_tag%%_*}
+        # UNTAGGING HERE
+        if datecheck "$backup_date" "$DaysKept"; then
+          [[ "$CleanupCount" == 0 ]] && echo "Removing backed up images older then $DaysKept days."
+          docker rmi "${repo_name}:${backup_tag}" && ((CleanupCount+=1))
+        fi
+      done
+      unset IFS
+      if [[ "$CleanupCount" == 0 ]]; then
+        printf "No backup images to remove.\n"
       else
-    printf "\nNo updates installed, exiting.\n"
+        printf "%b%s%b backup images removed.%b\n" "$c_green" "$CleanupCount" "$c_teal" "$c_reset"
+        docker image prune -f
       fi
     else
-  printf "\nNo updates available, exiting.\n"
+      if [[ "$AutoPrune" == false ]] && [[ "$AutoMode" == false ]]; then printf "\n"; read -rep "Would you like to prune all dangling images? y/[n]: " AutoPrune; fi
+      if [[ "$AutoPrune" == true ]] || [[ "$AutoPrune" =~ [yY] ]]; then printf "\nAuto pruning.."; docker image prune -f; fi
+    fi
+
+  else
+    printf "\nNo updates installed.\n"
+  fi
+else
+  printf "\nNo updates available.\n"
 fi
 
 exit 0