misc/ssh_tg_notify: Added cache to send fewer notifications

- per IP only once in the next 4 hours

roles/misc/ssh_tg_notify/defaults/main.yml

@@ -1,6 +1,8 @@
 ---
 
-notify_script: "{{ global_deployment_directory }}/ssh_notify/telegram.sh"
+notify_directory: "{{ global_deployment_directory }}/ssh_notify"
+notify_script: "{{ notify_directory }}/telegram.sh"
+notify_cache_directory: "{{ notify_directory }}/cache"
 
 # recipient_id
 bot_key: "{{ global_telegram_server_bot_key }}"

roles/misc/ssh_tg_notify/tasks/main.yml

@@ -7,13 +7,16 @@
       - curl
       - gawk
 
-- name: Create directory for notify script
+- name: Create directories for notify script
   file:
     state: directory
-    path: "{{ notify_script | dirname }}"
+    path: "{{ item }}"
     owner: root
     group: root
     mode: u=rwx,g=rx,o=
+  loop:
+    - "{{ notify_directory }}"
+    - "{{ notify_cache_directory }}"
 
 - name: Install notify script
   template:

roles/misc/ssh_tg_notify/templates/notify.sh

@@ -1,13 +1,22 @@
 #!/bin/bash
 # Modified version, original source: https://gitlab.com/snippets/1871482#note_188602535
 
+CACHE_DIR={{ notify_cache_directory | quote }}
 USERID={{ recipient_id | quote }}
 KEY={{ bot_key | quote }}
 
 TIMEOUT={{ timeout | quote }}
+
 URL="https://api.telegram.org/bot$KEY/sendMessage"
 if [[ "$PAM_SERVICE" == "sshd" && "$PAM_TYPE" == "open_session" && "$PAM_USER" != "git" && -z "$TMUX" ]]; then
     IP="$PAM_RHOST"
+    cache_file="$CACHE_DIR/$IP"
+    cache_mtime=$(stat --format="%Y" "$cache_file")
+    current_time=$(date +%s)
+    touch "$cache_file"
+    if (( cache_mtime > (current_time - 4*60*60) )); then
+        exit 0
+    fi
     HOSTNAME=$(hostname --fqdn)
     TEXT="Successful login from [$IP](https://ipinfo.io/$IP) for ${PAM_USER} @ ${HOSTNAME} ($(date "+%Y-%m-%d %H:%M"))"
     curl -s --max-time "$TIMEOUT" -d "chat_id=$USERID" -d "disable_web_page_preview=1" -d "parse_mode=Markdown" -d "text=$TEXT" "$URL" > /dev/null