[dspillett]

The question isn't about modifications to the library/service itself, but whether with other code linking to it in any way is what you have considered a derivative work that should also be covered by the AGPL.

For a library I'd say that was a definite yes. For a service it is someone's less clear, some provide connective tissue (language bindings or other access modules) under less strict licenses which creates an obvious break in the chain, without that or very definite answers to the question on the post you replied to it is unclear how tightly coupled you need to be to need to use AGPL for your own work and I would err on the side of assuming (because it is GPL based) any coupling would have that effect.

Not that this would put me off using LGPL, but it is just as disconcerting, if not more so, to commercial interests, as the GPL is.

[franga2000]

The "any coupling" logic would also make anything running on Linux GPL, which is definitely not the case. Using background service such as Minio as an unmodified black box for data storage as part of your app is unambiguously not derivative work. If you were to write something like a management UI for Minio and offer it with your hosted Minio service, then I can at least see the argument, although it still doesn't count under my reading of the AGPL.

[actionfromafar]

The Linux GPL license has an explicit excemption for binaries running under Linux. So it's not a great example.

https://github.com/torvalds/linux/blob/master/LICENSES/excep...

[dspillett]

The "or very definite answers to the question" is important there. Linus has explicitly answered the question, and if you use any of the Linux headers then yes you should release that software under the GPL. Under this circumstance your "which is definitely not the case" is incorrect.

[EDIT: after reading the information in the link provided by actionfromafar, I'm pull that back a bit: headers marked appropriately can be used and provided a shield similar to scales via glibc & similar (see below) - but check any headers you do use to make sure that they are in fact thusly marked (and note that this goes back to my "… or very definitely answers the question")]

It has also explicitly been said that making calls to the kernel indirectly by other means does not carry the same requirement, so if you use glibc (to give what is perhaps the most common example) and it causes the kernel to be called, you do not inherit GPL requirements from the kernel. What requirements you inherit depend on the license of the library, in this example LGPL which is glibc's license and that doesn't confer any such requirement from linking or other such coupling.

Whether this indirect call via another library that isn't itself GPL licensed acting as a shield holds generally, or just where explicitly stated as with Linux, I'm not sure off the top of my head. I'd have to reread the licence to refresh myself on the exact details and that isn't something I have the time to do right now, but in the case of Linux it doesn't matter if that is a general property or not because of specific things that have been officially stated.

There is a further exception that allows the making of binary blobs to act as drivers and such writing the kernel. I'm not sure if that is just a refinement of the same shield, or something more specific. Again I'd had to reread to be more sure (I've not gone over the "fine print" here in detail for some years).

> Using background service such as Minio as an unmodified black box for data storage as part of your app is unambiguously not derivative work.

That is certainly the case for LGPL, but by my understanding it isn't for GPL nor by extension AGPL. Minio's maintainers themselves shrug on the matter and suggest you either lawyer up or pay for commercial licensing if your work is not also AGPL and therefore directly compatible (see https://github.com/minio/minio/blob/master/COMPLIANCE.md).

[camgunz]

> That is certainly the case for LGPL, but by my understanding it isn't for GPL nor by extension AGPL.

If you don't modify, you have no obligations. Easy.

[dspillett]

Nope. That is LGPL. Under (A)GPL if you make a derivative work you have obligations even if you do not modify. Easy.

[Well, not so easy, as this discussion and the likes of Minio saying “get your own lawyer to tell you what our licence says” illustrate – what constitutes a derived work is apparently not objectively well-defined]

Don't believe me? Ask Google and their vast legal team: https://opensource.google/documentation/reference/using/agpl...

[camgunz]

Neither the AGPLv3 nor your link reference "derivative works". It's a GPLv2 concept they jettisoned for (A)GPLv3.

https://softwarefreedom.org/resources/2014/SFLC-Guide_to_GPL...

[camgunz]

Well that's not Op's question. They're asking "if I use Minio in my stack without modifications (as a file server that my other services interact with via an API), do I have to AGPL all the stuff the touches Minio or not?" (Minio is basically a FOSS S3) [0]. You're asking about linking, which is covered in the FAQ [1]:

"You have a GPLed program that I'd like to link with my code to build a proprietary program. Does the fact that I link with your program mean I have to GPL my program?"

"Not exactly. It means you must release your program under a license compatible with the GPL (more precisely, compatible with one or more GPL versions accepted by all the rest of the code in the combination that you link). The combination itself is then available under those GPL versions."

[0]: https://min.io/

[1]: https://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL

[dspillett]

I'm not sure that interpretation is correct. I don't read the intention that way (but I'd have to reread the licenses on detail to refresh myself before speaking more definitively).

Having said that, the fact that minio's documentation answers the question with a shrug and says "lawyer up" (see https://github.com/minio/minio/blob/master/COMPLIANCE.md) seems quite telling.

[camgunz]

I mean, they have a strong incentive to get you to buy a commercial license. I'm not surprised they're uninterested in giving you free legal advice in service of not paying them.

[dspillett]

That isn't what they say though. Their statement reads as “we don't actually fully know how the licence we have chosen works”.

The answer to “can I do X with your product?” shouldn't, in a reasonable world, constitute expensive legal advice. It feels rather shifty to me.

[camgunz]

Maybe, but that's more a comment about Minio than AGPLv3.

[richardwhiuk]

That's GPL, not AGPL. The AGPL license implies that communicating with it over the network is sufficiently to count as a violation.

[camgunz]

If you diff them, you'll see the AGPLv3 is essentially the GPLv3 with this extra clause added:

"13. Remote Network Interaction; Use with the GNU General Public License.

Notwithstanding any other provision of this License, if you modify the Program, your modified version must prominently offer all users interacting with it remotely through a computer network (if your version supports such interaction) an opportunity to receive the Corresponding Source of your version by providing access to the Corresponding Source from a network server at no charge, through some standard or customary means of facilitating copying of software. This Corresponding Source shall include the Corresponding Source for any work covered by version 3 of the GNU General Public License that is incorporated pursuant to the following paragraph."

Therefore, what I said about linking applies to both.

To be clear, you only have to offer source code if you've modified an AGPLv3 program and you're distributing it publicly or "interacting with it remotely through a computer network (if your version supports such interaction)". Op's scenario neither modifies Minio nor distributes it, so they're under no obligation to offer source.

[dspillett]

If connecting over the network doesn't constitute linking in a way that imposes AGPL obligations, then Google's position, or the reason they state for it, (https://opensource.google/documentation/reference/using/agpl...) is simply wrong. No offence, but I'm going to believe their expensive legal team not being able to find a way around this means that your interpretation is not correct.

[camgunz]

Ha well, as a lover of spirited conversation I am not at all offended. I'm not telling you you have to use (A)GPL code, I'm just trying to dispel various rumor.

I really, truly believe the GPLs have revolutionized our society. It's hard to imagine the internet and tech looking as good as they do (they could look way, way worse) without copyleft. Somewhere along the way we adopted this simplistic, hypothetical conception of freedom as "fewer restrictions and obligations", but experience gives us numerous counterpoints. Who is more free, the citizen of a country that protects against robbery, fraud, and violence, or the denizen of a lawless land? Oftentimes restricting one freedom (the freedom to kill, the freedom to close source) unlocks untold other freedoms (freedom to speak or worship without violence, freedom to build Google et al on the back of FOSS software). We've weirdly forgotten this, and I'm doing what I can to remind us.

That Google policy is actually heartening to me. It means that if I build some successful infra app and license it under the AGPLv3, there's zero chance I'll see it show up in GCP. That's a mission accomplished as far as I'm concerned.