Add a feature to notify users when a newer version of Argus is available

[lunkwill42]

Is your proposal related to a problem?

For someone who looks at Argus every day, it would be useful to be notified in Argus itself once a new version has been released, rather than having to follow other channels.

Also, GÉANT is interested in Argus uptake numbers, i.e. how many active Argus installations are there. There is no meaningful way to track this for open source software (the number of downloads is meaningless in this context, since most downloads are automated and do not represent an active installation), but a feature that makes a running Argus installation ping an HTTP endpoint to retrieve the latest version could be used to at least tally the number of potentially unique installations, quite anonymously.

The feature should be opt-out, though, as some users may consider such a ping feature (however anonymized it may be) an invasion of privacy.

Desired solution

Argus may intermittently (perhaps once per day) fetch a URL to see what the latest version number is. If a newer version than the running one is available, this could be flagged and a notification could be displayed somewhere in the main Argus dashboard.

An alternative suggested solution from a recent meeting was that this could be implemented as a glue service that posts an incident when the deployed Argus version becomes outdated. While it is an interesting suggestion

This information is already available through the GitHub API, since Argus uses GitHub releases, but this would not necessarily afford us access to tally the number of unique requests, so it may be necessary to make a proxy API hosted at GÉANT or Sikt.

[lunkwill42]

Idea: The URL to a service that provides the latest Argus release version number cannot be secret, so it can potentially be requested by any kind of bot or webcrawler. We might want Argus to use a specific User-Agent string to distinguish Argus requests from "background noise".