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+# tests
+
+## logs from loki
+
+```python
+# loki-get-last-to-sensor.py
+import sys, os, requests, datetime, time, json
+
+url = os.environ.get("LOKI_ADDRESS")
+
+if not url:
+    print(json.dumps({"state": "error", "log_message": "LOKI_ADDRESS is not set or empty"}))
+    sys.exit(1)
+
+query = os.environ.get("LOKI_QUERY")
+if not query:
+    print(json.dumps({"state": "error", "log_message": "LOKI_ADDRESS is not set or empty"}))
+    sys.exit(1)
+    
+
+end = int(time.time()) * 1_000_000_000
+start = (int(time.time()) - 24*60*60) * 1_000_000_000
+
+
+params = {
+    "query": query,
+    "limit": 1,
+    "direction": "backward",
+    "start": str(start),
+    "end": str(end),
+}
+
+resp = requests.get(url, params=params)
+data = resp.json()
+
+try:
+    ns = int(data["data"]["result"][0]["values"][0][0])
+    ts = ns / 1_000_000_000
+    dt = datetime.datetime.fromtimestamp(ts).strftime("%Y-%m-%d %H:%M:%S")
+    
+    print(json.dumps({
+       "state": dt,
+    }))
+
+except Exception:
+    print(json.dumps({"state": "unknown"}))
+```
+
+```yaml
+# example of the sensor
+name: git_limbosolutions_com_last_pbs_backup
+command: >
+  LOKI_ADDRESS=${LOKI_ADDRESS} LOKI_QUERY="{job=\"git-limbosolutions-com/pbs-backup\"} |= \"INFO: Finished Backup\"" python3 /config/scripts/loki-get-last-to-sensor.py
+value_template: "{{ value }}"
+```