[mosquitto-dev] Port 8081 of test.mosquitto.org

[ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) <nageshblore@xxxxxxxxx>]

Hi,

Hoping that this is the right forum to ask questions for MQTT test brokers, I am unable to connect to port 8081. As described at test.mosquitto.org, "Port 8081 has a Lets Encrypt certificate, so you should use your system CA certificates or the appropriate Lets Encrypt CA certificate for verification." If I try to connect without passing any option for CA (as mentioned in the documentation for test.mosquitto.org), the connection keeps failing without any information. If I provide a directory with the certificates (root and intermediate) as available here (https://letsencrypt.org/certificates/), I get an error as 'unable to get issuer certificate'.

While the experiments were run on Mac, I would like to know if it is fair to assume that /etc/ssl/certs will have Let's Encrypt CA on most platforms. Specifically, can I rely on this certificate to be available on GCR Distroless https://github.com/GoogleContainerTools/distroless ? I did use a multi-stage build to copy /etc/ssl/certs from base image - but, same error as in Experiment 2 below.

Therefore, if I do have to supply certificates externally, which certificates do I download?

Experiment 1 - No CA specified

Code - https://pastebin.com/LjsqCd81

Result:

Client disconnected.
Reconnecting

Experiment 2 - CA from Let's Encrypt used

Code - https://pastebin.com/DKeSgnNJ

Result:

Error: unable to get issuer certificate
Client disconnected.
Reconnecting

Thanks and regards,

Nagesh