LTI and juniper

While testing a new server with a fresh copy of juniper.alpha1 taken directly from the edX branch, I encountered a problem with LTI. Let me explain.

I exported and imported a course that previously worked in ironwood with LTI. A simple question I can access through LTI.

I replaced “lti” with “lti_consumer” in Studio for that course.

I even created new keys in Djando Admin.

I enabled “ENABLE_LTI_PROVIDER” in /edx/etc/lms.yml

I restarted the services.

All I get are these error messages when I try my course with http://ltiapps.net/test/tc.php :

Feb 10 11:23:55 ip-10-0-0-82 [service_variant=lms][oauthlib.oauth1.rfc5849.endpoints.signature_only][env:sandbox] INFO [ip-10-0-0-82 2621] [user None] [signature_only.py:81] - [Failure] request verification failed.
Feb 10 11:23:55 ip-10-0-0-82 [service_variant=lms][oauthlib.oauth1.rfc5849.endpoints.signature_only][env:sandbox] INFO [ip-10-0-0-82 2621] [user None] [signature_only.py:82] - Valid client: True
Feb 10 11:23:55 ip-10-0-0-82 [service_variant=lms][oauthlib.oauth1.rfc5849.endpoints.signature_only][env:sandbox] INFO [ip-10-0-0-82 2621] [user None] [signature_only.py:83] - Valid signature: False

The same course configuration with ironwood works perfectly while testing with http://ltiapps.net/test/tc.php. I am wondering if something changed with LTI between Ironwood and Juniper.

Any ideas?

Because I couldn’t find anything, I decided to install a new single server instance of ironwood.master. Just to check something.

I was surprised to discover that LTI wasn’t working either on that instance.

Did any of the libraries installed for oauth or LTI under /edx/app/edxapp/venvs/edxapp changed versions recently? I am comparing my test system and production system where LTI works under ironwood and there does not seem to be any change. Did I miss something obvious?