issue of running Mosquitto on Raspberry Pi 4

Product support
1

I am tring to run a mosquitto broker and two Rust applications that comunicate between over mqtt.

My docker-compose.yml

version: '2.1'

networks:
  mqtt:

services:
  mqtt-broker:
    build: ./mqtt-broker
    ports:
      - "1883:1883"
    networks:
      mqtt:
  
  mqtt-pub:
    build: ./mqtt-pub
    depends_on:
      - mqtt-broker
    networks:
      mqtt:

  mqtt-sub:
    build: ./mqtt-sub
    depends_on:
      - mqtt-broker
    networks:
      mqtt:

The Docker.template of each application looks like:

# Rust as the base image
FROM rust:slim-bookworm as builder

ENV UDEV=1
ENV RUST_BACKTRACE=1

# Create a new empty shell project
RUN USER=root cargo new --bin mqtt-sub
WORKDIR /usr/src/mqtt-sub

#stall dependencies
RUN apt-get update && apt-get install -y \
    git \
    cmake \
    libudev-dev \
    build-essential

# Copy our manifests
COPY ./Cargo.* ./
RUN mkdir ./src && echo 'fn main() { println!("Dummy!"); }' > ./src/main.rs

# Build only the dependencies to cache them
RUN cargo build --release --bin real && rm src/*.rs

# Now that the dependency is built, copy your source code
COPY ./src ./src/
RUN touch -a -m ./src/main.rs

# Build for release.
RUN cargo build --release --bin real --target-dir .

CMD [ "./release/real" ]

I use localhost as host and 1883 port.

I am getting this error:

[mqtt-pub] Error in event loop: Io(Os { code: 111, kind: ConnectionRefused, message: "Connection refused" })

My guess is that the containers cannot connect to the mosquitto broker.

2

Hello, are you able to successfully ping between the two containers?

Also note that if you are using Mosquitto 2.x then anonymous connections are disabled by default - check out their documentation for how to configure that differently if you need to.

3

I cannot ping between containers.

The Docker.template of mqtt-broker is:

FROM arm64v8/eclipse-mosquitto:2.0

COPY ./mosquitto.conf /mosquitto/config/mosquitto.conf

CMD ["/usr/sbin/mosquitto", "-c", "/mosquitto/config/mosquitto.conf"]

I am using a custom mosquitto.conf file for settin up the broker:

# Maximum connections (-1 for unlimited)
max_connections -1

# Standart MQTT connection
listener 1883 
protocol mqtt
allow_anonymous true

However if I run mosquitto -v in the mqtt-broker container I get this:

Spawning shell...
/ # mosquitto -v
1723189515: mosquitto version 2.0.18 starting
1723189515: Using default config.
1723189515: Starting in local only mode. Connections will only be possible from clients running on this machine.
1723189515: Create a configuration file which defines a listener to allow remote access.
1723189515: For more details see https://mosquitto.org/documentation/authentication-methods/
1723189515: Opening ipv4 listen socket on port 1883.
1723189515: Error: Address in use
1723189515: Opening ipv6 listen socket on port 1883.
1723189515: Error: Address not available
4

It might help to resolve the communication between containers first. Can you post your docker-compose file? Perhaps there is a networking conflict of some kind.

5

The docker-compose.yml is:

version: '2.1'

networks:
  mqtt:

services:
  mqtt-broker:
    build: ./mqtt-broker
    restart: always
    ports:
      - "1883:1883"
    networks:
      mqtt:
  
  mqtt-pub:
    build: ./mqtt-pub
    restart: always
    depends_on:
      - mqtt-broker
    networks:
      mqtt:

  mqtt-sub:
    build: ./mqtt-sub
    restart: always
    depends_on:
      - mqtt-broker
    networks:
      mqtt:
6

I am able to ping containers between them.

7

After pining the containers between them, I used the container name as host for MQTT.

let mut mqttoptions = MqttOptions::new("publisher", "mqtt-broker", 1883);

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