Docker image build from official Postgres image

[61131]

This PR includes a Dockerfile and entry point script required to produce a combined mqtt-pg-logger/Postgres image.

Standard parameters are configurable through environment variables as per the official Postgres image. Additionally the MQTT broker address can be set through the environment variable MQTT_BROKER.

This image can be pulled from https://hub.docker.com/r/robcasey/mqtt-pg-logger.

[agritheory]

@61131 I'd like to try this out, what are you running for the Docker command? Maybe worth adding that to the readme as well.

[61131]

@agritheory - This image inherits environment configuration options from the base Postgres image and adds an additional environment variable for the MQTT broker to which the logging client should connect. In my local testing where my MQTT server was running on host 10.0.0.1, I used the following docker command line to run the container.

docker run --name test-mqtt-pg-logger -p 5432:5432 -e MQTT_BROKER=10.0.0.1 -d robcasey/mqtt-pg-logger:latest

This will start the container running Postgres and the mqtt-pg-logger script, attempting to connect it to MQTT broker/server on host 10.0.0.1. All messages received by the mqtt-pg-logger client will then be logged to the database. The 5432:5432 port definition then allows me to connect to the Postgres database with other database tools (like DBeaver) to review collected message data.