mqtt-to-postgresql
2 minute read
mqtt-to-postgresql subscribes to the MQTT broker (in the stack this is VerneMQ), parses incoming messages on the topic “ia/#” and stores them in the postgresql / timescaleDB database (if they are in the correct datamodel)
Getting started
Here is a quick tutorial on how to start up a basic configuration / a basic docker-compose stack, so that you can develop.
docker-compose -f ./deployment/mqtt-to-postgresql/docker-compose-mqtt-to-postgresql-development.yml –env-file ./.env up -d –build
Message processing flow
Below diagram shows an abstract flow, of an incoming MQTT message.
Environment variables
This chapter explains all used environment variables.
POSTGRES_HOST
Description: Specifies the database DNS name / IP-address for postgresql / timescaleDB
Type: string
Possible values: all DNS names or IP
Example value: united-manufacturing-hub
POSTGRES_PORT
Description: Specifies the database port for postgresql
Type: int
Possible values: valid port number
Example value: 5432
POSTGRES_DATABASE
Description: Specifies the database name that should be used
Type: string
Possible values: an existing database in postgresql
Example value: factoryinsight
POSTGRES_USER
Description: Specifies the database user that should be used
Type: string
Possible values: an existing user with access to the specified database in postgresql
Example value: factoryinsight
POSTGRES_PASSWORD
Description: Specifies the database password that should be used
Type: string
Possible values: all
Example value: changeme
DRY_RUN
Description: Enables dry run mode (doing everything, even “writing” to database, except committing the changes.)
Type: string
Possible values: true,false
Example value: false
REDIS_URI
Description: URI for accessing redis sentinel
Type: string
Possible values: All valids URIs
Example value: united-manufacturing-hub-redis-node-0.united-manufacturing-hub-redis-headless:26379
REDIS_URI2
Description: Backup URI for accessing redis sentinel
Type: string
Possible values: All valids URIs
Example value: united-manufacturing-hub-redis-node-1.united-manufacturing-hub-redis-headless:26379
REDIS_URI3
Description: Backup URI for accessing redis sentinel
Type: string
Possible values: All valids URIs
Example value: united-manufacturing-hub-redis-node-2.united-manufacturing-hub-redis-headless:26379
REDIS_PASSWORD
Description: Password for accessing redis sentinel
Type: string
Possible values: all
Example value: changeme
MY_POD_NAME
Description: The pod name. Used only for tracing, logging and MQTT client id.
Type: string
Possible values: all
Example value: app-mqtttopostgresql-0
MQTT_TOPIC
Description: Topic to subscribe to. Only set for debugging purposes, e.g., to subscribe to a certain message type. Default usually works fine.
Type: string
Possible values: all possible MQTT topics
Example value: $share/MQTT_TO_POSTGRESQL/ia/#