Refactor notifications and add helper functions (#182)

* Refactor notifications and add helper functions

* Add helper functions to simplify sourcing files and executing functions if they exist

* Create notify_v2.sh wrapper script

* Simplify and consolidate notification logic within notify_v2.sh

* Support notification management via environment variables

* Move secrets to dockcheck.config

* Fix NOTIFY_CHANNELS default value when not set

* Feedback changes

* Remove leading spaces from MessageBody

* Check for valid notify v2 variables

* Warn on missing configuration and bypass notifications

* Update readme

* Additional feedback fixes

* More comments in default.config with different # depth for comments and settings

* Rename NOTIFY_TOPIC_NAME variable to NTFY_TOPIC_NAME for consistency

* Add TELEGRAM_TOPIC_ID

* Fix AppriseURL variable

* Add an ending newline to all MessageBody statements for consistency

* Remove troubleshooting echo statement

* Prevent attempting to trigger notifications for notification templates if versions are the same

---------

Co-authored-by: Matthew Oleksowicz <matt@everyoneneeds.it>

notify_templates/notify_pushover.sh

@@ -1,57 +1,26 @@
 ### DISCLAIMER: This is a third party addition to dockcheck - best effort testing.
-NOTIFY_PUSHOVER_VERSION="v0.1"
+NOTIFY_PUSHOVER_VERSION="v0.2"
 #
-# Copy/rename this file to notify.sh to enable the notification snippet.
 # Required receiving services must already be set up.
 # Requires jq installed and in PATH.
-# Modify to fit your setup - set Url and Token.
+# Do not modify this file directly. Set PUSHOVER_USER_KEY, PUSHOVER_TOKEN, and PUSHOVER_URL in your dockcheck.config file.
 
-FromHost=$(hostname)
+if [[ -z "${PUSHOVER_URL:-}" ]] || [[ -z "${PUSHOVER_USER_KEY:-}" ]] || [[ -z "${PUSHOVER_TOKEN:-}" ]]; then
+  printf "Pushover notification channel enabled, but required configuration variables are missing. Pushover notifications will not be sent.\n"
 
-trigger_notification() {
-    # Modify to fit your setup:
-    PushoverUrl="https://api.pushover.net/1/messages.json"
-    PushoverUserKey="Your Pushover User Key Here"
-    PushoverToken="Your Pushover API Token Here"
+  remove_channel pushover
+fi
 
-    # Sending the notification via Pushover
-    curl -sS -o /dev/null --show-error --fail -X POST \
-        -F "token=$PushoverToken" \
-        -F "user=$PushoverUserKey" \
-        -F "title=$MessageTitle" \
-        -F "message=$MessageBody" \
-        $PushoverUrl
-}
+trigger_pushover_notification() {
+  PushoverUrl="${PUSHOVER_URL}" # e.g. PUSHOVER_URL=https://api.pushover.net/1/messages.json
+  PushoverUserKey="${PUSHOVER_USER_KEY}" # e.g. PUSHOVER_USER_KEY=userkey
+  PushoverToken="${PUSHOVER_TOKEN}" # e.g. PUSHOVER_TOKEN=token-value
 
-send_notification() {
-    [ -s "$ScriptWorkDir"/urls.list ] && releasenotes || Updates=("$@")
-    UpdToString=$( printf '%s\\n' "${Updates[@]}" )
-
-    # platform specific notification code would go here
-    printf "\nSending pushover notification\n"
-
-    MessageTitle="$FromHost - updates available."
-    # Setting the MessageBody variable here.
-    printf -v MessageBody "🐋 Containers on $FromHost with updates available:\n$UpdToString"
-
-    trigger_notification
-}
-
-### Rename (eg. disabled_dockcheck_notification), remove or comment out the following function
-### to not send notifications when dockcheck itself has updates.
-dockcheck_notification() {
-    printf "\nSending pushover dockcheck notification\n"
-
-    MessageTitle="$FromHost - New version of dockcheck available."
-    # Setting the MessageBody variable here.
-    printf -v MessageBody "Installed version: $1 \nLatest version: $2 \n\nChangenotes: $3"
-
-    RawNotifyUrl="https://raw.githubusercontent.com/mag37/dockcheck/main/notify_templates/notify_pushover.sh"
-    LatestNotifyRelease="$(curl -s -r 0-150 $RawNotifyUrl | sed -n "/NOTIFY_PUSHOVER_VERSION/s/NOTIFY_PUSHOVER_VERSION=//p" | tr -d '"')"
-    if [[ "$NOTIFY_PUSHOVER_VERSION" != "$LatestNotifyRelease" ]] ; then
-        printf -v NotifyUpdate "\n\nnotify_pushover.sh update avialable:\n $NOTIFY_PUSHOVER_VERSION -> $LatestNotifyRelease\n"
-        MessageBody="${MessageBody}${NotifyUpdate}"
-    fi
-
-    trigger_notification
-}
+  # Sending the notification via Pushover
+  curl -sS -o /dev/null --show-error --fail -X POST \
+      -F "token=$PushoverToken" \
+      -F "user=$PushoverUserKey" \
+      -F "title=$MessageTitle" \
+      -F "message=$MessageBody" \
+      $PushoverUrl
+}