Initial commit: LAN Checker

Network health monitoring script with MQTT reporting for Home Assistant.
- Ping, HTTP, and SNMP checkers
- MQTT Discovery for automatic entity creation
- Configurable check intervals

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

config.yaml.example

@@ -0,0 +1,52 @@
+# LAN Checker Configuration
+
+mqtt:
+  host: "192.168.1.100"
+  port: 1883
+  username: ""
+  password: ""
+  client_id: "lan_checker"
+
+# Default interval between checks in seconds
+default_interval: 60
+
+checks:
+  # Ping checks
+  - id: router
+    name: "Router"
+    type: ping
+    host: "192.168.1.1"
+    interval: 30
+    timeout: 5
+
+  - id: nas
+    name: "NAS Synology"
+    type: ping
+    host: "192.168.1.50"
+    interval: 60
+
+  # HTTP checks
+  - id: homeassistant
+    name: "Home Assistant"
+    type: http
+    url: "http://192.168.1.100:8123"
+    expected_status: 200
+    timeout: 10
+    interval: 60
+
+  - id: plex
+    name: "Plex Server"
+    type: http
+    url: "http://192.168.1.50:32400/web"
+    expected_status: 200
+    verify_ssl: false
+    interval: 120
+
+  # SNMP checks
+  - id: switch
+    name: "Switch Managed"
+    type: snmp
+    host: "192.168.1.2"
+    community: "public"
+    oid: "1.3.6.1.2.1.1.1.0"  # sysDescr
+    interval: 120