add telegraf output script

telegraf.py

@@ -0,0 +1,72 @@
+import logging
+from sys import argv
+from tomllib import load
+
+import paho.mqtt.client as mqtt
+
+with open(argv[1], "rb") as f:
+    config = load(f)
+
+MQTT_SUB = "{}/".format(config["mqtt"]["prefix"])
+
+logging.basicConfig(level=logging.DEBUG)
+LOG = logging.getLogger(__name__)
+
+
+def out(keys, value):
+    print(
+        "{},{} value={}".format(
+            config["telegraf"]["measurement"],
+            ",".join([f"{k}={v}" for k, v in keys.items()]),
+            value,
+        ),
+        flush=True,
+    )
+
+
+def on_connect(client, userdata, flags, rc):
+    LOG.info(f"Connected to mqtt server")
+    mqtt.subscribe(f"{MQTT_SUB}#")
+    LOG.info(f"subscribing to {MQTT_SUB}")
+
+
+def on_disconnect(client, userdata, rc):
+    LOG.info(f"Disconnected from mqtt server")
+
+
+def on_message(client, userdata, msg):
+    try:
+        topic = msg.topic[len(MQTT_SUB) :]
+        if "/" in topic:
+            k1, k2 = topic.split("/", 1)
+            out(
+                {
+                    "measurement": k1,
+                    "line": k2,
+                },
+                msg.payload.decode(),
+            )
+        else:
+            out(
+                {
+                    "measurement": topic,
+                },
+                msg.payload.decode(),
+            )
+    except Exception:
+        LOG.exception(f"could not parse {msg.topic!r} {msg.payload!r}")
+
+
+try:
+    LOG.info("mooooin!")
+    mqtt = mqtt.Client()
+    mqtt.on_connect = on_connect
+    mqtt.on_disconnect = on_disconnect
+    mqtt.on_message = on_message
+    mqtt.connect(config["mqtt"]["host"], config["mqtt"]["port"], 10)
+
+    LOG.info("starting loop")
+    mqtt.loop_forever()
+    LOG.info("bye")
+except Exception:
+    LOG.exception("oops")