Label rework + clearer messages (#228)

- Moved up label check and logic to earlier in the process, to iterate the whole run the same way if `-l` option is passed.
- Added messaging to make it clearer.
- Clarified Readme and --help message.
- Clarified prune message (to mean ALL dangling, not just currently updated).

README.md

@@ -69,7 +69,7 @@ Options:
 -h     Print this Help.
 -i     Inform - send a preconfigured notification.
 -I     Prints custom releasenote urls alongside each container with updates in CLI output (requires urls.list).
--l     Only update if label is set. See readme.
+-l     Only include containers with label set. See readme.
 -m     Monochrome mode, no printf colour codes and hides progress bar.
 -M     Prints custom releasenote urls as markdown (requires template support).
 -n     No updates, only checking availability.
@@ -283,10 +283,12 @@ Optionally add labels to compose-files. Currently these are the usable labels:
       mag37.dockcheck.only-specific-container: true
       mag37.dockcheck.restart-stack: true
 ```
-- `mag37.dockcheck.update: true` will when used with the `-l` option only update containers with this label and skip the rest. Will still list updates as usual.
+- `mag37.dockcheck.update: true` will when used with the `-l` option only check and update containers with this label set and skip the rest.  
 - `mag37.dockcheck.only-specific-container: true` works instead of the `-F` option, specifying the updated container when doing compose up, like `docker compose up -d homer`.
 - `mag37.dockcheck.restart-stack: true` works instead of the `-f` option, forcing stop+restart on the whole compose-stack (Caution: Will restart on every updated container within stack).
 
+Adding or modifying labels in compose-files requires a restart of the container to take effect.
+
 ## Workaround for non **amd64** / **arm64**
 `regctl` provides binaries for amd64/arm64, to use on other architecture you could try this workaround.
 Run regctl in a container wrapped in a shell script. Copied from [regclient/docs/install.md](https://github.com/regclient/regclient/blob/main/docs/install.md):

dockcheck.sh

@@ -42,7 +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 "-l     Only update if label is set. See readme."
+  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)."
   echo "-n     No updates; only checking availability without interaction."
@@ -424,6 +424,10 @@ check_image() {
     printf "%s\n" "NoUpdates !$i - not checked, no compose file"
     return
   fi
+  # Checking if Label Only -option is set, and if container got the label
+  ContUpdateLabel=$($jqbin -r '."mag37.dockcheck.update"' <<< "$ContLabels")
+  [[ "$ContUpdateLabel" == "null" ]] && ContUpdateLabel=""
+  [[ "$OnlyLabel" == true ]] && { [[ "$ContUpdateLabel" != true ]] && { echo "Skip $i"; return; } }
 
   local NoUpdates GotUpdates GotErrors
   ImageId=$(docker inspect "$i" --format='{{.Image}}')
@@ -449,7 +453,7 @@ check_image() {
 # Make required functions and variables available to subprocesses
 export -f check_image datecheck
 export Excludes_string="${Excludes[*]:-}" # Can only export scalar variables
-export t_out regbin RepoUrl DaysOld DRunUp jqbin
+export t_out regbin RepoUrl DaysOld DRunUp jqbin OnlyLabel
 
 # Check for POSIX xargs with -P option, fallback without async
 if (echo "test" | xargs -P 2 >/dev/null 2>&1) && [[ "$MaxAsync" != 0 ]]; then
@@ -479,6 +483,8 @@ done < <( \
   xargs $XargsAsync -I {} bash -c 'check_image "{}"' \
 )
 
+[[ "$OnlyLabel" == true ]] && printf "\n%bLabel option active:%b Only checking containers with labels set.\n" "$c_blue" "$c_reset"
+
 # Sort arrays alphabetically
 IFS=$'\n'
 NoUpdates=($(sort <<<"${NoUpdates[*]:-}"))
@@ -534,10 +540,6 @@ if [[ -n "${GotUpdates:-}" ]]; then
       ContImage=$(docker inspect "$i" --format='{{.Config.Image}}')
       ContPath=$($jqbin -r '."com.docker.compose.project.working_dir"' <<< "$ContLabels")
       [[ "$ContPath" == "null" ]] && ContPath=""
-      ContUpdateLabel=$($jqbin -r '."mag37.dockcheck.update"' <<< "$ContLabels")
-      [[ "$ContUpdateLabel" == "null" ]] && ContUpdateLabel=""
-      # Checking if Label Only -option is set, and if container got the label
-      [[ "$OnlyLabel" == true ]] && { [[ "$ContUpdateLabel" != true ]] && { echo "No update label, skipping."; continue; } }
 
       # Checking if compose-values are empty - hence started with docker run
       if [[ -z "$ContPath" ]]; then
@@ -569,8 +571,6 @@ if [[ -n "${GotUpdates:-}" ]]; then
       [[ "$ContName" == "null" ]] && ContName=""
       ContEnv=$($jqbin -r '."com.docker.compose.project.environment_file"' <<< "$ContLabels")
       [[ "$ContEnv" == "null" ]] && ContEnv=""
-      ContUpdateLabel=$($jqbin -r '."mag37.dockcheck.update"' <<< "$ContLabels")
-      [[ "$ContUpdateLabel" == "null" ]] && ContUpdateLabel=""
       ContRestartStack=$($jqbin -r '."mag37.dockcheck.restart-stack"' <<< "$ContLabels")
       [[ "$ContRestartStack" == "null" ]] && ContRestartStack=""
       ContOnlySpecific=$($jqbin -r '."mag37.dockcheck.only-specific-container"' <<< "$ContLabels")
@@ -579,8 +579,6 @@ if [[ -n "${GotUpdates:-}" ]]; then
       printf "\n%bNow recreating (%s/%s): %b%s%b\n" "$c_teal" "$CurrentQue" "$NumberofUpdates" "$c_blue" "$i" "$c_reset"
       # Checking if compose-values are empty - hence started with docker run
       [[ -z "$ContPath" ]] && { echo "Not a compose container, skipping."; continue; }
-      # Checking if Label Only -option is set, and if container got the label
-      [[ "$OnlyLabel" == true ]] && { [[ "$ContUpdateLabel" != true ]] && { echo "No update label, skipping."; continue; } }
 
       # cd to the compose-file directory to account for people who use relative volumes
       cd "$ContPath" || { printf "\n%bPath error - skipping%b %s" "$c_red" "$c_reset" "$i"; continue; }
@@ -603,7 +601,7 @@ if [[ -n "${GotUpdates:-}" ]]; then
         ${DockerBin} ${CompleteConfs} ${ContEnvs} up -d ${SpecificContainer} || { printf "\n%bDocker error, exiting!%b\n" "$c_red" "$c_reset" ; exit 1; }
       fi
     done
-    if [[ "$AutoPrune" == false ]] && [[ "$AutoMode" == false ]]; then printf "\n"; read -rep "Would you like to prune dangling images? y/[n]: " AutoPrune; fi
+    if [[ "$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"
   else