Mosquittoでタイムスタンプを表示

課題

mosquitto_sub でイベントにタイムスタンプがないのが困る時がある。

mosquitto_subでメッセージを受け取った時間を出す場合は、-F '%j' とやっておくと良い。メッセージを受信したらタイムスタンプがわかる。

{"tst":"2024-12-04T13:59:41.439232+0900","topic":"t1","qos":0,"retain":0,"payloadlen":35,"payload":"{\"time\":\"2024-12-04T13:59:41+0900\"}"}

ただ、この方法だとイベントは時間がわからない。たとえばPINGはこんな感じ。

Client s33b07786 sending CONNECT
Client s33b07786 received CONNACK (0)
Client s33b07786 sending SUBSCRIBE (Mid: 1, Topic: t1, QoS: 0, Options: 0x00)
Client s33b07786 received SUBACK
Subscribed (mid: 1): 0
Client s33b07786 sending PINGREQ
Client s33b07786 received PINGRESP
Client s33b07786 sending PINGREQ
Client s33b07786 received PINGRESP
Client s33b07786 sending PINGREQ

方法

これにタイムスタンプをつける。ts は brew install moreutils

stdbuf -oL \
` --cafile AmazonRootCA1.pem \
  --cert device.pem.crt \
  --key private.pem.key \
  -h <CODE>.iot.ap-northeast-1.amazonaws.com \
  -p 8883 \
  -t t1 \
  -i sf6b19c86 \
  -k 1200 \
  -F '%j' \
  -d | ts

こんな感じになる。

Dec 04 12:18:21 Client sf6b19c86 sending CONNECT
Dec 04 12:18:21 Client sf6b19c86 received CONNACK (0)
Dec 04 12:18:21 Client sf6b19c86 sending SUBSCRIBE (Mid: 1, Topic: t1, QoS: 0, Options: 0x00)
Dec 04 12:18:21 Client sf6b19c86 received SUBACK
Dec 04 12:18:21 Subscribed (mid: 1): 0
Dec 04 12:38:21 Client sf6b19c86 sending PINGREQ
Dec 04 12:38:21 Client sf6b19c86 received PINGRESP
Dec 04 13:00:03 Client sf6b19c86 sending PINGREQ
Dec 04 13:00:03 Client sf6b19c86 received PINGRESP
Dec 04 13:20:03 Client sf6b19c86 sending PINGREQ
Dec 04 13:20:03 Client sf6b19c86 received PINGRESP
Dec 04 13:40:03 Client sf6b19c86 sending PINGREQ
Dec 04 13:40:03 Client sf6b19c86 received PINGRESP
Dec 04 13:59:41 Client sf6b19c86 received PUBLISH (d0, q0, r0, m0, 't1', ... (35 bytes))
Dec 04 13:59:41 {"tst":"2024-12-04T13:59:41.439232+0900","topic":"t1","qos":0,"retain":0,"payloadlen":35,"payload":"{\"time\":\"2024-12-04T13:59:41+0900\"}"}