virtuos / opencast-ca-display

Information display for Opencast Capture Agents

Opencast Capture Agent Display

Software backend for displays showing the current state of Opencast capture agents.

Build & Run

Make sure to install Go. This should be something like:

❯ dnf install golang

Then run the project with:

❯ go run main.go

…or build a static binary:

❯ go build

Example

The display control in action:

opencast-ca-display-prototype.mp4

• The display and laptop do not know about each other
• The laptop is running an Opencast capture agent
• When the laptop starts capturing video, the display shows an active recording

Opencast User

To improve security, you can limit the access rights for the Opencast user by creating a user which has only read access to the capture agent status API and nothing else.

To do this, first create a new security rule in your Opencast's etc/security/mh_default_org.xml allowing read access for a new role ROLE_CAPTURE_AGENT_CALENDAR:

<!-- Enable capture agent updates and ingest -->
<sec:intercept-url pattern="/capture-admin/agents/**" method="GET" access="ROLE_ADMIN, ROLE_CAPTURE_AGENT, ROLE_CAPTURE_AGENT_CALENDAR" />
<sec:intercept-url pattern="/capture-admin/**" access="ROLE_ADMIN, ROLE_CAPTURE_AGENT" />

Next, go to the Opencast REST Docs → /user-utils and fill out the form for POST / with data like this:

• username: ca-display
• password: secret-password
• roles: ["ROLE_CAPTURE_AGENT_CALENDAR"]

You should now be able to use this new user.

opencast-ca-display's Issues

Additional displayed field

The additional field should display

• the start of the next recording IF there is no current recording OR
• the remaining duration of the active recording IF there is one

The field should be placed somewhere near the bottom of the display. The font does not have to be extremely large, instead it should be readable from a close.

Automate builds

It would be great if we could automate build and…

• add them as assets on build runs for pushes and pull requests (example)
• add them as attachments to releases (example; also creates the release)

Make display text configurable

Include assets in binary

ARM builds

Maybe we can build ARM binaries using GitHub Actions.
See https://github.com/marketplace/actions/arm-runner

Adjust proxy settings

Gin complains about the current proxy settings:

[GIN-debug] [WARNING] You trusted all proxies, this is NOT safe. We recommend you to set a value.
Please check https://pkg.go.dev/github.com/gin-gonic/gin#readme-don-t-trust-all-proxies for details.

Make Opencast request asyncronous

• We don't want/need to proxy the request to Opencast every time

Show how the display works

Here is a video showing the display control in action:

opencast-ca-display-prototype.mp4

• The display and laptop do not know about each other
• The laptop is running an Opencast capture agent
• When the laptop starts capturing video, the display shows an active recording

Improve logging

• Introduce proper logging with proper log levels
• Make log level configurable
• Ensure errors are being logged

Pinch zoom should not work

Since the display we use is a touch display, you can pinch-zoom on the display. This is not something we want. Can we disable that?

If that doesn't work, we should at least make sure that we get back to a good state eventually and use something like a refresh meta HTML tag to reload the UI every hour or so.