Getting invalid remote certificate error when setting up listening tentacle

[davidkeaveny]

Hi there, I am installing Octopus Tentacle v4.0.1 (x64) on a clean install of Windows Server 2016, and trying to add the tentacle to an existing Octopus Server v2019.2.4. When I add the URL of the server and the API key, I get the following error:

Error: Unable to connect to the Octopus Deploy server. See the inner exception for details.
An error occurred while sending the request.
The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.
The remote certificate is invalid according to the validation procedure.

The web portal is being served with a valid certificate, and if I navigate in the browser to the server URL, I get a certificate warning saying that the certificate (named Octopus Portal) is not trusted.

All my other tentacles are working correctly, it has been almost a year since I last had to add a tentacle, and that was without issues.

[henrik (Henrik Andersson)]

Hi David,

Thanks for getting in touch!

Are you trying to setup a new Polling or Listening Tentacle? From your description of the issue I assume you’re trying to configure a Polling Tentacle.

What URL are you using when registering your Tentacle? We’ve seen this error when customers have put in their Octopus URL including the communications port Octopus is configured with, i.e. https://your.octopus.url:10943 when you should just use https://your.octopus.url

Thank you and best regards,
Henrik

[davidkeaveny]

Hi Henrik,

Yes you are right, I was using the Octopus port number in the URI; removing it fixed the issue.

Many thanks!
David