Adapt to Grafana's new licensing

[olix0r]

Grafana is now going to be distributed under the AGPLv3 https://grafana.com/blog/2021/04/20/grafana-loki-tempo-relicensing-to-agplv3/

I'm not lawyerly enough to articulate the implications of this on Linkerd's use of Grafana in the viz extension but, before upgrading Grafana, we'll need to understand this more fully so that those who are adopting or distributing Linkerd--an Apache v2 licensed project--can make informed decisions about the use AGPLv3 code.

As a starting point, we may want to entirely separate a linkerd-grafana extension so that linkerd-viz can be installed without having to worry about these licensing restrictions.

[olix0r]

As I understand it, as long as we're distributing an unmodified Grafana image, that shouldn't impact the rest of Linkerd's licensing. My main questions are:

• If we extend Grafana base images with our configurations, is that considered modification?
• Does (hyper-)linking to Grafana from the Linkerd CLI or Web UI constitute "linking" in the same sense as it would for library code?

My expectation is that both of these scenarios are benign and Linkerd can effectively "wrap" Grafana's AGPLv3 code; but I'm really not an expert on this.

[stefanprodan]

I see you are relicensing with Apache here https://github.com/linkerd/linkerd2/blob/main/grafana/Dockerfile#L3, maybe that's an issue? @olix0r have you opened a ticket in CNCF Servicedesk around this? We also distribute Grafana as part of Flux monitoring stack, but we don't build our own container yet. Once our dashboards will hit the ectd limit we'll have to do same thing as you.

[stefanprodan]

@olix0r looks like we need to stop updating Grafana and stick to the last version released under Apache, see https://twitter.com/cra/status/1384859663615864833?s=20

This is a sad day for most CNCF projects....

[coderanger]

Not a lawyer but I was sent this thread from someone with questions so an attempt to bring things back to reality a bit:

If we extend Grafana base images with our configurations, is that considered modification?

It wouldn't be a modification as you are not modifying any Grafana source code. However it miiiiight be a derived work. The FSF's position is that dynamic linking does activate virality and Docker layering is kind of like dynamic linking if you squint really hard. However the FSF's position is not reflected in US case law which holds the opposite view, that a combined work involving both sides does not in and of itself create a derived work relationship. This is an area that actual lawyers should weigh in on but I wouldn't assume it would be a problem and as a specific case we can potential request Grafana put their Dockerfiles back under Apache2 as they have for the JS libraries and related code.

Does (hyper-)linking to Grafana from the Linkerd CLI or Web UI constitute "linking" in the same sense as it would for library code?

No, flatly and clearly. What it does do is activate the AGPL's code sharing provisions meaning if a user of Linkerd asks for the source code of Grafana, give them a link to https://github.com/grafana/grafana and you're in compliance with the license.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[kriswill]

Please be aware that this is highly unlikely to be granted, and that the Governing Board has (at the time of this writing) not previously granted any exceptions for components that are under AGPL-3.0.

From: https://github.com/cncf/foundation/blob/master/agpl-recommendations.md#seek-an-exception-from-the-governing-board