Docker deployment

Deploy MQTT Gateway using Docker containers

Deploy MQTT Gateway using Docker for consistent, isolated environments across different systems.

Prerequisites

• Docker installed and running
• Access to a MariaDB instance
• Access to an MQTT broker
• Network connectivity between containers and external services

Build the Docker image

1. Build the image

   Build the Docker image from the project root:

   docker build -t mqtt-gateway:latest .
   

   The Dockerfile uses Python 3.12-slim as the base image and installs all dependencies from requirements.txt:

   FROM python:3.12-slim
   
   ENV PYTHONDONTWRITEBYTECODE=1
   ENV PYTHONUNBUFFERED=1
   
   WORKDIR /app
   
   RUN addgroup --system app && adduser --system --ingroup app app
   
   COPY requirements.txt .
   RUN pip install --no-cache-dir -r requirements.txt
   
   COPY . .
   
   CMD ["python", "app.py"]
   
2. Verify the image

   Confirm the image was built successfully:

   docker images | grep mqtt-gateway
   

Run the container

1. Create log directory

   Create a directory on the host to persist logs:

   mkdir -p ./log
   
2. Run with environment variables

   Run the container with required environment variables:

   docker run --rm \
     -e DB_HOST=192.168.0.137 \
     -e DB_PORT=3306 \
     -e DB_NAME=db \
     -e DB_USER=demo \
     -e DB_PASSWORD=demo \
     -e LOG_DIR=/app/log \
     -v "$(pwd)/log:/app/log" \
     --name mqtt-gateway \
     mqtt-gateway:latest
   

Environment variables

Configure the gateway using these environment variables:

Variable	Required	Default	Description
DB_HOST	Yes	-	MariaDB host address
DB_PORT	No	3306	MariaDB port
DB_NAME	Yes	-	Database name
DB_USER	Yes	-	Database user
DB_PASSWORD	Yes	-	Database password
LOG_DIR	No	./log	Directory for log files
HTTP_TIMEOUT_SECONDS	No	10	HTTP request timeout for POST_ENDPOINT flows
MQTT_CLIENT_ID	No	mqtt-gateway	MQTT client identifier
MQTT_KEEPALIVE	No	60	MQTT keepalive interval in seconds
FLOWS_RELOAD_INTERVAL_SECONDS	No	600	Interval to reload flows (10 minutes)

Volume mounts

The container requires one volume mount for persistent logs:

-v "$(pwd)/log:/app/log"

This mounts the host’s ./log directory to /app/log inside the container, ensuring logs persist after the container stops.

Network configuration

Ensure the Docker container can reach both the MariaDB database and MQTT broker. If running on a custom Docker network, use the --network flag.

Connect to existing network

docker run --rm \
  --network my-network \
  -e DB_HOST=mariadb \
  -e DB_PORT=3306 \
  -e DB_NAME=db \
  -e DB_USER=demo \
  -e DB_PASSWORD=demo \
  -e LOG_DIR=/app/log \
  -v "$(pwd)/log:/app/log" \
  --name mqtt-gateway \
  mqtt-gateway:latest

Run in background

Run the container as a daemon using the -d flag:

docker run -d \
  -e DB_HOST=192.168.0.137 \
  -e DB_PORT=3306 \
  -e DB_NAME=db \
  -e DB_USER=demo \
  -e DB_PASSWORD=demo \
  -e LOG_DIR=/app/log \
  -v "$(pwd)/log:/app/log" \
  --name mqtt-gateway \
  --restart unless-stopped \
  mqtt-gateway:latest

The --restart unless-stopped policy ensures the container restarts automatically if it crashes.

View logs

View container logs using Docker commands:

# View all logs
docker logs mqtt-gateway

# Follow logs in real-time
docker logs -f mqtt-gateway

# View last 100 lines
docker logs --tail 100 mqtt-gateway

Application error logs are written to the mounted volume at ./log/YYYY-MM-DD.log.

Stop the container

docker stop mqtt-gateway

If running with --rm, the container is automatically removed when stopped. Otherwise, remove it manually:

docker rm mqtt-gateway