Subscribe to MQTT

If you have installed the chirpstack-gateway-os-full image, then a MQTT broker (Mosquitto) is pre-installed and pre-configured.

Subscribing

The MQTT broker is pre-configured with two listeners. Connections from the same host (Raspberry Pi) no not require a client-certificate or any credentials. If you are connecting from a different host, then you must use a client-certificate in order to connect to the MQTT broker. This client-certificate can be generated using the ChirpStack web-interface. Please find instructions below.

Same host

If connecting from the same machine (Raspberry Pi), you can use the following command to receive data:

mosquitto_sub -h localhost -t "application/#" -v

Different host

If connecting from a different host, you must obtain a client-certificate first using the ChirpStack web-interface.

• Navigate to the application for which you want to receive data
• Click the Integrations tab
• Click Get certificate under the MQTT integration card
• Click Generate certificate to obtain the certificate files
• Store the three files on the machine from which you want to connect to the MQTT broker:
  • CA certificate: ca.pem
  • TLS certificate: cert.pem
  • TLS key: key.pem

After completing the above steps, you can use the following command to receive data:

mosquitto_sub -h IPADDRESS -p 8883 --insecure --cafile ca.pem --cert cert.pem --key key.pem  -t "application/#" -v

Note: Replace IPADDRESS with the IP address of the Raspberry Pi. Also note the --insecure flag, which is required to ignore the certificate hostname validation.