Integrating Opencast in an LMS using LTI

What it does

The Opencast LTI module provides an easy way to integrate Opencast into a Learning Management System (LMS), or any other system which supports the LTI standard as an LTI tool consumer.

Typically, students enrolled in a course access Opencast through an LTI tool in the LMS course site, and can play back videos in an Opencast series set up for the course.

More information about the LTI specifications is available at IMS Learning Tools Interoperability.

Configure Opencast

Configure OAuth authentication

LTI uses OAuth to authenticate users. To enable OAuth in Opencast, edit OPENCAST/etc/security/mh_default_org.xml and uncomment the oAuthProtectedResourceFilter in the Authentication Filters section:

    <!-- 2-legged OAuth is used by trusted 3rd party applications, including LTI. -->
    <!-- Uncomment the line below to support LTI or other OAuth clients.          -->
    <ref bean="oauthProtectedResourceFilter" />

To configure OAuth consumers (e.g. a LMS), edit OPENCAST/etc/org.opencastproject.kernel.security.OAuthConsumerDetailsService.cfg and replace CONSUMERNAME, CONSUMERKEY, and CONSUMERSECRET with the values you will use in your LMS:

oauth.consumer.name.1=CONSUMERNAME
oauth.consumer.key.1=CONSUMERKEY
oauth.consumer.secret.1=CONSUMERSECRET

Configure LTI (optional)

To give LMS users the same username in Opencast as the LMS username, edit etc/org.opencastproject.kernel.security.LtiLaunchAuthenticationHandler.cfg and add the configured OAuth consumer key to the list of highly trusted keys.

lti.oauth.highly_trusted_consumer_key.1=CONSUMERKEY

Use can exempt specific users even if a highly trusted consumer is used by configuring a blacklist. Additionally, there are settings for excluding the system administrator as well as the digest user (enabled by default).

lti.allow_system_administrator=false
lti.allow_digest_user=false
lti.blacklist.user.1=myAdminUser

Notice: Marking a consumer key as highly trusted can be a security risk! If the usernames of sensitive Opencast users are not blacklisted, the LMS administrator could create LMS users with the same username and use LTI to grant that user access to Opencast. In the default configuration, that includes the admin and opencast_system_account users.

Configure and test an LTI tool in the LMS

Configure an LTI tool in the LMS with these values:

  • LTI launch URL: OPENCAST-URL/lti
  • LTI key: the value chosen for CONSUMERKEY in org.opencastproject.kernel.security.OAuthConsumerDetailsService.cfg
  • LTI secret: the value chosen for CONSUMERSECRET in org.opencastproject.kernel.security.OAuthConsumerDetailsService.cfg

In a clustered Opencast system, choose the URL of the presentation server where the media module and player are available.

Access the LTI tool configured for Opencast in the LMS. The Opencast LTI Welcome page should appear. Click on the links provided to OPENCAST-URL/lti and OPENCAST-URL/info/me.json to verify the LTI parameters provided to Opencast by the LMS, and the list of roles which the LTI user has in Opencast.

LTI roles

LTI users will only see Opencast series and videos which are public, or those to which they have access because of the Opencast roles which they have. The Opencast LTI module grants an LTI user the role(s) formed from the LTI parameters context_id and roles.

The LTI context is typically the LMS course ID, and the default LTI role for a student in a course is Learner. The Opencast role granted would therefore be SITEID_Learner.

To make a series or video visible to students who access Opencast through LTI in an LMS course, add the role SITEID_Learner to the Series or Event Access Control List (ACL).

LTI users may also have additional roles if the LTI user is created as an Opencast user in the Admin UI and given additional roles, or if one or more Opencast User Providers or Role Providers are configured.

Customize the LTI tool in the LMS

Opencast will redirect an LTI user to the URL specified by the LTI custom tool parameter. Some LMS systems allow custom parameters to be defined separately in each place where an LTI tool is used, whereas other systems only allow custom parameters to be defined globally.

  • To show the Opencast Media Module, use tool=engage/ui/
  • To show all videos for a single series, use tool=ltitools/series/index.html;series=SERIESID
  • To show a single video, use tool=engage/theodul/ui/core.html;id=MEDIAPACKAGEID
  • To show a short debugging page before proceeding to the tool page, add the parameter test=true

For more information about how to set custom LTI parameters, please check the documentation of your LMS.