MQTT Bridge

The technical documentation of the mqtt-bridge microservice, which acts as a communication bridge between two MQTT brokers.

MQTT-bridge is a microservice that connects two MQTT brokers and forwards messages between them. It is used to connect the local broker of the edge computer with the remote broker on the server.

How it works

This microservice subscribes to topics on the local broker and publishes the messages to the remote broker, while also subscribing to topics on the remote broker and publishing the messages to the local broker.

Kubernetes resources

  • StatefulSet: united-manufacturing-hub-mqttbridge
  • Secret: united-manufacturing-hub-mqttbridge-mqtt-secrets
  • PersistentVolumeClaim: united-manufacturing-hub-mqttbridge-claim


You can configure the URL of the remote MQTT broker that MQTT-bridge should connect to by setting the value of the remoteBrokerUrl parameter in the _000_commonConfig.mqttBridge section of the Helm chart values file.

Environment variables

Environment variables
Variable nameDescriptionTypeAllowed valuesDefault
BRIDGE_ONE_WAYWhether to enable one-way communication, from local to remotebooltrue, falsetrue
INSECURE_SKIP_VERIFY_LOCALSkip TLS certificate verification for the local brokerbooltrue, falsetrue
INSECURE_SKIP_VERIFY_REMOTESkip TLS certificate verification for the remote brokerbooltrue, falsetrue
LOCAL_BROKER_SSL_ENABLEDWhether to enable SSL for the local MQTT brokerbooltrue, falsetrue
LOCAL_BROKER_URLURL for the local MQTT brokerstringAnyssl://united-manufacturing-hub-mqtt:8883
LOCAL_CERTIFICATE_NAMESet to NO_CERT to allow non-encrypted MQTT access, or to USE_TLS to use TLS encryptionstringUSE_TLS, NO_CERTUSE_TLS
LOCAL_PUB_TOPICLocal MQTT topic to publish tostringAnyia
LOCAL_SUB_TOPICLocal MQTT topic to subscribe tostringAnyia/factoryinsight
REMOTE_BROKER_SSL_ENABLEDWhether to enable SSL for the remote MQTT brokerbooltrue, falsetrue
REMOTE_BROKER_URLURL for the local MQTT brokerstringAnyssl://united-manufacturing-hub-mqtt.united-manufacturing-hub:8883
REMOTE_CERTIFICATE_NAMESet to NO_CERT to allow non-encrypted MQTT access, or to USE_TLS to use TLS encryptionstringUSE_TLS, NO_CERTUSE_TLS
REMOTE_PUB_TOPICRemote MQTT topic to publish tostringAnyia/factoryinsight
REMOTE_SUB_TOPICRemote MQTT topic to subscribe tostringAnyia