mqtt2influxdb

An opinionated and intentionally scope-limited MQTT to InfluxDB bridge.

Note

This README is incomplete (tracked in #1).

Goals & Features

• Get simple JSON data from MQTT to InfluxDB
• Straightforward; easy to learn about, configure, and run
• Take advantage of orchestration features from e.g. systemd or Docker Compose
• Allow health monitoring via an outgoing heartbeat, HTTP GET, and/or Docker's health check

Non-goals

Multiple topics/subscriptions

tk orchestration, retries, etc

Infinitely flexible schema/transformations

tk can't necessarily work with every message format can't necessarily work with weird key names or most nested structures doesn't support non-JSON

Usage

tk

Arguments

tk

• -env-files
• -strict
• -help
• -version

note, strict overrides FIELDTAG_DETERMINATION_FAILURE and CAST_FAILURE

Docker

tk

Timestamps

The timestamp for each InfluxDB point defaults to the time the message was processed.

If the message contains a top-level entry named at, ts, or time, that value will be parsed and used as the timestamp.

rtl_433 compatibility

tk: -M time:iso:utc:tz

Key Names, Canonicalization, and Nesting

tk

per The Open Group Base Specifications https://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html , any char other than NUL or = is allowed in an env var name.

Influx disallows(ish) ( https://docs.influxdata.com/influxdb/v1/write_protocols/line_protocol_reference/#special-characters ): #, and the names time, _field, _measurement.

For sanity I also disallow ASCII control chars (character code 0-31). And I recommend you don't use periods (.) or mixed case as that could cause collisions.

lowercased except in env vars, when they're all uppercased.

Configuration

tk

MQTT

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• MQTT_SERVER
• MQTT_TOPIC
• MQTT_USER
• MQTT_PASS
• MQTT_QOS
• MQTT_CLIENT_ID
• MQTT_CLEAN_START
• MQTT_KEEP_ALIVE_S
• MQTT_SESSION_EXPIRY_S

Influx

tk

• INFLUX_SERVER
• INFLUX_USER
• INFLUX_PASS
• INFLUX_BUCKET
• INFLUX_MEASUREMENT_NAME
• INFLUX_TIMEOUT_S
• INFLUX_RETRIES
• INFLUX_TAGS

Field/Tag Mapping

tk

Typically, we auto TK

Format: M2I_<canonicalized-name>_ISA=<field|tag|drop>

• FIELDTAG_DETERMINATION_FAILURE: ignore, log, or fatal

Data Type Hints

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Format: M2I_<canonicalized-field-name>_TYPE=<int|float|double|string|bool>

• CAST_FAILURE: ignore, log, or fatal
• DEFAULT_NUMBERS_TO_FLOAT: true or false

Heartbeat

tk

• HEARTBEAT_GET_URL
• HEARTBEAT_INTERVAL_S
• HEARTBEAT_THRESHOLD_S
• HEALTH_PORT

Timestamp Parsing

If a message contains a timestamp field, it must be a string and will be parsed as an RFC3339 timestamp.

Note

Timestamps from an Apple platform formatted as NSISO8601DateFormatWithInternetDateTime will be parsed correctly by this program.

In the future, multiple timestamp formats may be supported; see #3.

Deduplication

tk; for JSON mode only

• DEDUPE_ON

Multiple .env files

tk

License

This software is licensed under the LGPL-3.0 license. See LICENSE in this repo.

Author

Chris Dzombak

• dzombak.com
• GitHub @cdzombak