From 57650f16736359cb49217896c54f20e946727fbb Mon Sep 17 00:00:00 2001
From: vorezal <37914382+vorezal@users.noreply.github.com>
Date: Thu, 29 May 2025 16:43:34 -0400
Subject: [PATCH] Notify_v2.sh bug fixes (#188)

* Notify_v2.sh bug fixes

* Clarify notify_v2.sh usage in README.md

* Fix JSON newline handling in Discord and Telegram channels

* Additional error messages when notification templates fail to be sourced

* Additional variable for self-hosted ntfy.sh domain

* Notify_v2.sh additional fixes

* Clarify usage in README.md and notify template comments

* Support sourcing template files from project root

* Add days old message to notification title

* Handle JSON with jq in Discord and Telegram templates

* Tweak notify_v2.sh usage docs and comments

* Remove extra newline from notification body

* replaced jq with jqbin, reodered setting of jqbin, changed source for hostname var

* moved the setting of jqbin a bit further up after further testing

---------

Co-authored-by: Matthew Oleksowicz <matt@everyoneneeds.it>
Co-authored-by: mag37 <robin.ivehult@gmail.com>
---
 .gitignore                            |  2 +-
 README.md                             | 24 +++++++++++++++++++-
 default.config                        |  2 ++
 dockcheck.sh                          |  6 ++---
 notify_templates/notify_DSM.sh        |  4 +++-
 notify_templates/notify_apprise.sh    |  4 +++-
 notify_templates/notify_discord.sh    | 14 ++++++++----
 notify_templates/notify_gotify.sh     |  6 +++--
 notify_templates/notify_matrix.sh     |  4 +++-
 notify_templates/notify_ntfy-sh.sh    | 13 +++++++----
 notify_templates/notify_pushbullet.sh |  8 ++++---
 notify_templates/notify_pushover.sh   |  4 +++-
 notify_templates/notify_slack.sh      |  4 +++-
 notify_templates/notify_smtp.sh       |  4 +++-
 notify_templates/notify_telegram.sh   | 16 ++++++++++----
 notify_templates/notify_v2.sh         | 32 ++++++++++++++++++---------
 16 files changed, 109 insertions(+), 38 deletions(-)

diff --git a/.gitignore b/.gitignore
index da5921c..da6210f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,5 @@
 # ignore users custom notify.sh
-/notify.sh
+/notify*.sh
 /urls.list
 # ignore user config
 /dockcheck.config
diff --git a/README.md b/README.md
index e66eb7d..73662bb 100644
--- a/README.md
+++ b/README.md
@@ -136,9 +136,31 @@ Run it scheduled with `-ni` to only get notified when there's updates available!
 
 V2 installation and configuration (tag v0.6.5 or later):
 Remove or rename `notify.sh` if previously configured using the legacy method.
+Make certain your project directory is laid out as below. You only need the notify_v2.sh file and any notification templates you wish to enable, but there is no harm in having all of them present.
+```
+ .
+├── notify_templates/
+│   ├── notify_DSM.sh
+│   ├── notify_apprise.sh
+│   ├── notify_discord.sh
+│   ├── notify_generic.sh
+│   ├── notify_gotify.sh
+│   ├── notify_matrix.sh
+│   ├── notify_ntfy-sh.sh
+│   ├── notify_pushbullet.sh
+│   ├── notify_pushover.sh
+│   ├── notify_slack.sh
+│   ├── notify_smtp.sh
+│   ├── notify_telegram.sh
+│   └── notify_v2.sh
+├── dockcheck.config
+├── dockcheck.sh
+└── urls.list         # optional
+```
+If you wish to customize `notify_v2.sh` or the notify templates yourself, you may copy them to your project root directory alongside the main dockcheck.sh script (where they will also be ignored by git).
 Uncomment and set the NOTIFY_CHANNELS environment variable in `dockcheck.config` to a space separated string of your desired notification channels to enable.
 Uncomment and set the environment variables related to the enabled notification channels.
-It is recommended not to make changes directly to the `notify_X.sh` template files and to use only environment variables defined in `dockcheck.config` using this method.
+It is recommended not to make changes directly to the `notify_X.sh` template files within the `notify_templates` subdirectory and instead use only environment variables defined in `dockcheck.config` using this method.
 
 Legacy installation and configuration:
 Use a previous version of a `notify_X.sh` template file (tag v0.6.4 or earlier) from the **notify_templates** directory,
diff --git a/default.config b/default.config
index 9c13be0..cd26f57 100644
--- a/default.config
+++ b/default.config
@@ -54,6 +54,8 @@
 # MATRIX_ROOM_ID="myroom"
 # MATRIX_SERVER_URL="https://matrix.yourdomain.tld"
 #
+## ntfy.sh or your custom domain with no trailing /
+# NTFY_DOMAIN="ntfy.sh"
 # NTFY_TOPIC_NAME="YourUniqueTopicName"
 #
 # PUSHBULLET_URL="https://api.pushbullet.com/v2/pushes"
diff --git a/dockcheck.sh b/dockcheck.sh
index cccc6dc..3a2a04e 100755
--- a/dockcheck.sh
+++ b/dockcheck.sh
@@ -332,6 +332,9 @@ dependency_check() {
   ${!AppVar} "$VerFlag" &> /dev/null  || { printf "%s\n" "$AppName is not working - try to remove it and re-download it, exiting."; exit 1; }
 }
 
+dependency_check "regctl" "regbin" "https://github.com/regclient/regclient/releases/latest/download/regctl-linux-TEMP"
+dependency_check "jq" "jqbin" "https://github.com/jqlang/jq/releases/latest/download/jq-linux-TEMP"
+
 # Numbered List function
 # if urls.list exists add release note url per line
 list_options() {
@@ -357,9 +360,6 @@ fi
 # Version check for notify templates
 [[ "$Notify" == true ]] && [[ ! -s "${ScriptWorkDir}/notify.sh" ]] && { exec_if_exists_or_fail notify_update_notification || printf "Could not source notify notification function.\n"; }
 
-dependency_check "regctl" "regbin" "https://github.com/regclient/regclient/releases/latest/download/regctl-linux-TEMP"
-dependency_check "jq" "jqbin" "https://github.com/jqlang/jq/releases/latest/download/jq-linux-TEMP"
-
 # Check docker compose binary
 docker info &>/dev/null || { printf "\n%bYour current user does not have permissions to the docker socket - may require root / docker group. Exiting.%b\n" "$c_red" "$c_reset"; exit 1; }
 if docker compose version &>/dev/null; then DockerBin="docker compose" ;
diff --git a/notify_templates/notify_DSM.sh b/notify_templates/notify_DSM.sh
index 17d697f..edfb51f 100644
--- a/notify_templates/notify_DSM.sh
+++ b/notify_templates/notify_DSM.sh
@@ -4,7 +4,9 @@ NOTIFY_DSM_VERSION="v0.2"
 #
 # mSMTP/sSMTP has to be installed and configured manually.
 # The existing DSM Notification Email configuration will be used automatically.
-# Do not modify this file directly. Set DSM_SENDMAILTO and DSM_SUBJECTTAG in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set DSM_SENDMAILTO and DSM_SUBJECTTAG in your dockcheck.config file.
 
 MSMTP=$(which msmtp)
 SSMTP=$(which ssmtp)
diff --git a/notify_templates/notify_apprise.sh b/notify_templates/notify_apprise.sh
index e71a4df..4da3d71 100644
--- a/notify_templates/notify_apprise.sh
+++ b/notify_templates/notify_apprise.sh
@@ -2,7 +2,9 @@
 NOTIFY_APPRISE_VERSION="v0.2"
 #
 # Required receiving services must already be set up.
-# Do not modify this file directly. Set APPRISE_PAYLOAD in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set APPRISE_PAYLOAD in your dockcheck.config file.
 # If API, set APPRISE_URL instead.
 
 if [[ -z "${APPRISE_PAYLOAD:-}" ]] && [[ -z "${APPRISE_URL:-}" ]]; then
diff --git a/notify_templates/notify_discord.sh b/notify_templates/notify_discord.sh
index a28cda5..97bf1fa 100644
--- a/notify_templates/notify_discord.sh
+++ b/notify_templates/notify_discord.sh
@@ -1,8 +1,10 @@
 ### DISCLAIMER: This is a third party addition to dockcheck - best effort testing.
-NOTIFY_DISCORD_VERSION="v0.2"
+NOTIFY_DISCORD_VERSION="v0.3"
 #
 # Required receiving services must already be set up.
-# Do not modify this file directly. Set DISCORD_WEBHOOK_URL in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set DISCORD_WEBHOOK_URL in your dockcheck.config file.
 
 if [[ -z "${DISCORD_WEBHOOK_URL:-}" ]]; then
   printf "Discord notification channel enabled, but required configuration variables are missing. Discord notifications will not be sent.\n"
@@ -13,6 +15,10 @@ fi
 trigger_discord_notification() {
   DiscordWebhookUrl="${DISCORD_WEBHOOK_URL}" # e.g. DISCORD_WEBHOOK_URL=https://discord.com/api/webhooks/<token string>
 
-  MsgBody="{\"username\":\"$FromHost\",\"content\":\"$MessageBody\"}"
-  curl -sS -o /dev/null --fail -X POST -H "Content-Type: application/json" -d "$MsgBody" "$DiscordWebhookUrl"
+  JsonData=$( "$jqbin" -n \
+              --arg username "$FromHost" \
+              --arg body "$MessageBody" \
+              '{"username": $username, "content": $body}' )
+
+  curl -sS -o /dev/null --fail -X POST -H "Content-Type: application/json" -d "$JsonData" "$DiscordWebhookUrl"
 }
diff --git a/notify_templates/notify_gotify.sh b/notify_templates/notify_gotify.sh
index f66e7e8..4e373d6 100644
--- a/notify_templates/notify_gotify.sh
+++ b/notify_templates/notify_gotify.sh
@@ -2,7 +2,9 @@
 NOTIFY_GOTIFY_VERSION="v0.3"
 #
 # Required receiving services must already be set up.
-# Do not modify this file directly. Set GOTIFY_TOKEN and GOTIFY_DOMAIN in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set GOTIFY_TOKEN and GOTIFY_DOMAIN in your dockcheck.config file.
 
 if [[ -z "${GOTIFY_TOKEN:-}" ]] || [[ -z "${GOTIFY_DOMAIN:-}" ]]; then
   printf "Gotify notification channel enabled, but required configuration variables are missing. Gotify notifications will not be sent.\n"
@@ -20,7 +22,7 @@ trigger_gotify_notification() {
       ContentType="text/plain"
   fi
 
-  JsonData=$( jq -n \
+  JsonData=$( "$jqbin" -n \
                 --arg body "$MessageBody" \
                 --arg title "$MessageTitle" \
                 --arg type "$ContentType" \
diff --git a/notify_templates/notify_matrix.sh b/notify_templates/notify_matrix.sh
index 87215ae..8cf20b5 100644
--- a/notify_templates/notify_matrix.sh
+++ b/notify_templates/notify_matrix.sh
@@ -2,7 +2,9 @@
 NOTIFY_MATRIX_VERSION="v0.2"
 #
 # Required receiving services must already be set up.
-# Do not modify this file directly. Set MATRIX_ACCESS_TOKEN, MATRIX_ROOM_ID, and MATRIX_SERVER_URL in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set MATRIX_ACCESS_TOKEN, MATRIX_ROOM_ID, and MATRIX_SERVER_URL in your dockcheck.config file.
 
 if [[ -z "${MATRIX_ACCESS_TOKEN:-}" ]] || [[ -z "${MATRIX_ROOM_ID}:-" ]] || [[ -z "${MATRIX_SERVER_URL}:-" ]]; then
   printf "Matrix notification channel enabled, but required configuration variables are missing. Matrix notifications will not be sent.\n"
diff --git a/notify_templates/notify_ntfy-sh.sh b/notify_templates/notify_ntfy-sh.sh
index 0b5cc3a..5a189c5 100644
--- a/notify_templates/notify_ntfy-sh.sh
+++ b/notify_templates/notify_ntfy-sh.sh
@@ -1,17 +1,22 @@
 ### DISCLAIMER: This is a third party addition to dockcheck - best effort testing.
-NOTIFY_NTFYSH_VERSION="v0.3"
+NOTIFY_NTFYSH_VERSION="v0.4"
 #
 # Setup app and subscription at https://ntfy.sh
-# Do not modify this file directly. Set NTFY_TOPIC_NAME in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set NTFY_DOMAIN and NTFY_TOPIC_NAME in your dockcheck.config file.
 
-if [[ -z "${NTFY_TOPIC_NAME:-}" ]]; then
+if [[ -z "${NTFY_DOMAIN:-}" ]] || [[ -z "${NTFY_TOPIC_NAME:-}" ]]; then
   printf "Ntfy.sh notification channel enabled, but required configuration variables are missing. Ntfy.sh notifications will not be sent.\n"
 
   remove_channel ntfy-sh
 fi
 
 trigger_ntfy-sh_notification() {
-  NtfyUrl="ntfy.sh/${NTFY_TOPIC_NAME}" # e.g. NTFY_TOPIC_NAME=YourUniqueTopicName
+  NtfyUrl="${NTFY_DOMAIN}/${NTFY_TOPIC_NAME}"
+  # e.g.
+  # NTFY_DOMAIN=ntfy.sh
+  # NTFY_TOPIC_NAME=YourUniqueTopicName
 
   if [[ "$PrintMarkdownURL" == true ]]; then
       ContentType="Markdown: yes"
diff --git a/notify_templates/notify_pushbullet.sh b/notify_templates/notify_pushbullet.sh
index 4bad2ff..182c78d 100644
--- a/notify_templates/notify_pushbullet.sh
+++ b/notify_templates/notify_pushbullet.sh
@@ -3,7 +3,9 @@ NOTIFY_PUSHBULLET_VERSION="v0.2"
 #
 # Required receiving services must already be set up.
 # Requires jq installed and in PATH.
-# Do not modify this file directly. Set PUSHBULLET_TOKEN and PUSHBULLET_URL in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set PUSHBULLET_TOKEN and PUSHBULLET_URL in your dockcheck.config file.
 
 if [[ -z "${PUSHBULLET_URL:-}" ]] || [[ -z "${PUSHBULLET_TOKEN:-}" ]]; then
   printf "Pushbullet notification channel enabled, but required configuration variables are missing. Pushbullet notifications will not be sent.\n"
@@ -16,5 +18,5 @@ trigger_pushbullet_notification() {
   PushToken="${PUSHBULLET_TOKEN}" # e.g. PUSHBULLET_TOKEN=token-value
 
   # Requires jq to process json data
-  jq -n --arg title "$MessageTitle" --arg body "$MessageBody" '{body: $body, title: $title, type: "note"}' | curl -sS -o /dev/null --show-error --fail -X POST -H "Access-Token: $PushToken" -H "Content-type: application/json" $PushUrl -d @-
-}
\ No newline at end of file
+  "$jqbin" -n --arg title "$MessageTitle" --arg body "$MessageBody" '{body: $body, title: $title, type: "note"}' | curl -sS -o /dev/null --show-error --fail -X POST -H "Access-Token: $PushToken" -H "Content-type: application/json" $PushUrl -d @-
+}
diff --git a/notify_templates/notify_pushover.sh b/notify_templates/notify_pushover.sh
index 16fff6a..2f8bdda 100644
--- a/notify_templates/notify_pushover.sh
+++ b/notify_templates/notify_pushover.sh
@@ -3,7 +3,9 @@ NOTIFY_PUSHOVER_VERSION="v0.2"
 #
 # Required receiving services must already be set up.
 # Requires jq installed and in PATH.
-# Do not modify this file directly. Set PUSHOVER_USER_KEY, PUSHOVER_TOKEN, and PUSHOVER_URL in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set PUSHOVER_USER_KEY, PUSHOVER_TOKEN, and PUSHOVER_URL in your dockcheck.config file.
 
 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"
diff --git a/notify_templates/notify_slack.sh b/notify_templates/notify_slack.sh
index 6dc3b28..a760f3d 100644
--- a/notify_templates/notify_slack.sh
+++ b/notify_templates/notify_slack.sh
@@ -2,7 +2,9 @@
 NOTIFY_SLACK_VERSION="v0.2"
 #
 # Setup app and token at https://api.slack.com/tutorials/tracks/posting-messages-with-curl
-# Do not modify this file directly. Set SLACK_ACCESS_TOKEN, and SLACK_CHANNEL_ID in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set SLACK_ACCESS_TOKEN, and SLACK_CHANNEL_ID in your dockcheck.config file.
 
 if [[ -z "${SLACK_ACCESS_TOKEN:-}" ]] || [[ -z "${SLACK_CHANNEL_ID:-}" ]]; then
   printf "Slack notification channel enabled, but required configuration variables are missing. Slack notifications will not be sent.\n"
diff --git a/notify_templates/notify_smtp.sh b/notify_templates/notify_smtp.sh
index 8573640..2889475 100644
--- a/notify_templates/notify_smtp.sh
+++ b/notify_templates/notify_smtp.sh
@@ -3,7 +3,9 @@ NOTIFY_SMTP_VERSION="v0.2"
 # INFO: ssmtp is depcerated - consider to use msmtp instead.
 #
 # mSMTP/sSMTP has to be installed and configured manually.
-# Do not modify this file directly. Set SMTP_MAIL_FROM, SMTP_MAIL_TO, and SMTP_SUBJECT_TAG in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set SMTP_MAIL_FROM, SMTP_MAIL_TO, and SMTP_SUBJECT_TAG in your dockcheck.config file.
 
 if [[ -z "${SMTP_MAIL_FROM:-}" ]] || [[ -z "${SMTP_MAIL_TO:-}" ]] || [[ -z "${SMTP_SUBJECT_TAG:-}" ]]; then
   printf "SMTP notification channel enabled, but required configuration variables are missing. SMTP notifications will not be sent.\n"
diff --git a/notify_templates/notify_telegram.sh b/notify_templates/notify_telegram.sh
index 1230524..d254490 100644
--- a/notify_templates/notify_telegram.sh
+++ b/notify_templates/notify_telegram.sh
@@ -1,8 +1,10 @@
 ### DISCLAIMER: This is a third party addition to dockcheck - best effort testing.
-NOTIFY_TELEGRAM_VERSION="v0.2"
+NOTIFY_TELEGRAM_VERSION="v0.3"
 #
 # Required receiving services must already be set up.
-# Do not modify this file directly. Set TELEGRAM_CHAT_ID and TELEGRAM_TOKEN in your dockcheck.config file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
+# Do not modify this file directly within the "notify_templates" subdirectory. Set TELEGRAM_CHAT_ID and TELEGRAM_TOKEN in your dockcheck.config file.
 
 if [[ -z "${TELEGRAM_CHAT_ID:-}" ]] || [[ -z "${TELEGRAM_TOKEN:-}" ]]; then
   printf "Telegram notification channel enabled, but required configuration variables are missing. Telegram notifications will not be sent.\n"
@@ -21,7 +23,13 @@ trigger_telegram_notification() {
   TelegramChatId="${TELEGRAM_CHAT_ID}" # e.g. TELEGRAM_CHAT_ID=mychatid
   TelegramUrl="https://api.telegram.org/bot$TelegramToken"
   TelegramTopicID=${TELEGRAM_TOPIC_ID:="0"}
-  TelegramData="{\"chat_id\":\"$TelegramChatId\",\"text\":\"$MessageBody\",\"message_thread_id\":\"$TelegramTopicID\",\"disable_notification\": false}"
 
-  curl -sS -o /dev/null --fail -X POST "$TelegramUrl/sendMessage" -H 'Content-Type: application/json' -d "$TelegramData"
+  JsonData=$( "$jqbin" -n \
+              --arg chatid "$TelegramChatId" \
+              --arg text "$MessageBody" \
+              --arg thread "$TelegramTopicID" \
+              --arg parse_mode "$ParseMode" \
+              '{"chat_id": $chatid, "text": $text, "message_thread_id": $thread, "disable_notification": false, "parse_mode": $parse_mode, "disable_web_page_preview": true}' )
+
+  curl -sS -o /dev/null --fail -X POST "$TelegramUrl/sendMessage" -H 'Content-Type: application/json' -d "$JsonData"
 }
diff --git a/notify_templates/notify_v2.sh b/notify_templates/notify_v2.sh
index 3beb5ef..5990e1a 100644
--- a/notify_templates/notify_v2.sh
+++ b/notify_templates/notify_v2.sh
@@ -1,6 +1,8 @@
-NOTIFY_V2_VERSION="v0.1"
+NOTIFY_V2_VERSION="v0.2"
 #
 # If migrating from an older notify template, remove your existing notify.sh file.
+# Leave (or place) this file in the "notify_templates" subdirectory within the same directory as the main dockcheck.sh script.
+# If you instead wish make your own modifications, make a copy in the same directory as the main dockcheck.sh script.
 # Enable and configure all required notification variables in your dockcheck.config file, e.g.:
 # NOTIFY_CHANNELS=apprise gotify slack
 # SLACK_TOKEN=xoxb-some-token-value
@@ -8,7 +10,7 @@ NOTIFY_V2_VERSION="v0.1"
 
 enabled_notify_channels=( ${NOTIFY_CHANNELS:-} )
 
-FromHost=$(hostname)
+FromHost=$(cat /etc/hostname)
 
 remove_channel() {
   local temp_array=()
@@ -19,21 +21,29 @@ remove_channel() {
 }
 
 for channel in "${enabled_notify_channels[@]}"; do
-  source_if_exists "${ScriptWorkDir}/notify_templates/notify_${channel}.sh"
+  source_if_exists_or_fail "${ScriptWorkDir}/notify_${channel}.sh" || \
+  source_if_exists_or_fail "${ScriptWorkDir}/notify_templates/notify_${channel}.sh" || \
+  printf "The notification channel ${channel} is enabled, but notify_${channel}.sh was not found. Check the ${ScriptWorkDir} directory or the notify_templates subdirectory.\n"
 done
 
 send_notification() {
   [[ -s "$ScriptWorkDir"/urls.list ]] && releasenotes || Updates=("$@")
   UpdToString=$( printf '%s\\n' "${Updates[@]}" )
+  UpdToString=${UpdToString%\\n}
 
   for channel in "${enabled_notify_channels[@]}"; do
     printf "\nSending ${channel} notification\n"
 
-    MessageTitle="$FromHost - updates available."
-    # Setting the MessageBody variable here.
-    printf -v MessageBody "🐋 Containers on $FromHost with updates available:\n$UpdToString\n"
+    # To be added in the MessageBody if "-d X" was used
+    # leading space is left intentionally for clean output
+    [[ -n "$DaysOld" ]] && msgdaysold="with images ${DaysOld}+ days old " || msgdaysold=""
 
-    exec_if_exists trigger_${channel}_notification "$@"
+    MessageTitle="$FromHost - updates ${msgdaysold}available."
+    # Setting the MessageBody variable here.
+    printf -v MessageBody "🐋 Containers on $FromHost with updates available:\n${UpdToString}\n"
+
+    exec_if_exists_or_fail trigger_${channel}_notification || \
+    printf "Attempted to send notification to channel ${channel}, but the function was not found. Make sure notify_${channel}.sh is available in the ${ScriptWorkDir} directory or notify_templates subdirectory.\n"
   done
 }
 
@@ -48,7 +58,8 @@ dockcheck_notification() {
     if [[ ${#enabled_notify_channels[@]} -gt 0 ]]; then printf "\n"; fi
     for channel in "${enabled_notify_channels[@]}"; do
       printf "Sending dockcheck update notification - ${channel}\n"
-      exec_if_exists trigger_${channel}_notification
+      exec_if_exists_or_fail trigger_${channel}_notification || \
+      printf "Attempted to send notification to channel ${channel}, but the function was not found. Make sure notify_${channel}.sh is available in the ${ScriptWorkDir} directory or notify_templates subdirectory.\n"
     done
   fi
 }
@@ -62,7 +73,7 @@ notify_update_notification() {
     for notify_script in "${update_channels[@]}"; do
       upper_channel=$(tr '[:lower:]' '[:upper:]' <<< "$notify_script")
       VersionVar="NOTIFY_${upper_channel}_VERSION"
-      if [[ -n "${!VersionVar}" ]]; then
+      if [[ -n "${!VersionVar:-}" ]]; then
         RawNotifyUrl="https://raw.githubusercontent.com/mag37/dockcheck/main/notify_templates/notify_${notify_script}.sh"
         LatestNotifyRelease="$(curl -s -r 0-150 $RawNotifyUrl | sed -n "/NOTIFY_${upper_channel}_VERSION/s/NOTIFY_${upper_channel}_VERSION=//p" | tr -d '"')"
         LatestNotifyRelease=${LatestNotifyRelease:-undefined}
@@ -74,7 +85,8 @@ notify_update_notification() {
 
             for channel in "${enabled_notify_channels[@]}"; do
               printf "Sending notify_${notify_script}.sh update notification - ${channel}\n"
-              exec_if_exists trigger_${channel}_notification
+              exec_if_exists_or_fail trigger_${channel}_notification || \
+              printf "Attempted to send notification to channel ${channel}, but the function was not found. Make sure notify_${channel}.sh is available in the ${ScriptWorkDir} directory or notify_templates subdirectory.\n"
             done
           fi
         fi