Add a text to explain the time window for GC

[AllForNothing]

1.Fixes #18692
UI change:

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[AllForNothing]

@OrlinVasilev Can you help to review the English text in this PR?
We add this text to explain the time window for GC

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[Vad1mo]

IMO the text is vague. It has too much room for interpretation. Furthermore, there are words that actually need to have an introduction and explanation because the meaning is not clear or vague:

Specifically:

• How long is the time window
• What is happens inside and outside this time window?
• What does "covers" mean exactly?

Isn't the time window is hard-coded to 2h?

Why not write it in more simple words, explaining the restriction?

We can turn this -> Any garbage collection operation (including the dry run) only covers images that were not uploaded within the specified time window"

In more in simple words, straight to the point, that doesn't need any additional lookup.

• EN: Artifacts uploaded in the past 2 hours are excluded from garbage collection.
• DE: Artefakte, die in den vergangenen 2 Stunden hochgeladen wurden, sind von der Garbage Collection ausgenommen.
• ES: Los artefactos cargados en las últimas 2 horas se excluyen de la recogida de basura.**

[OrlinVasilev]

Agree with @Vad1mo we need clear and simple explanations.
and based on the docs Vadim's proposal is clear and correct
@AllForNothing can you implement it this way please

[AllForNothing]

@OrlinVasilev @Vad1mo Thanks for the comments.
But I don't know if '2 hrs' is proper here, because the time window is an environment variable that is hard-coded as 2 hrs by default, and users can modify it.
What about "Artifacts uploaded within the specified time window(the default is 2 hrs) are excluded from garbage collection"?

[OrlinVasilev]

@AllForNothing if it's tuneable variable the documentations is not pointing that: https://goharbor.io/docs/2.8.0/administration/garbage-collection/#run-garbage-collection

To avoid damaging the uploading artifact, the garbage collection introduces a time windows(2 hours) to reserve the recent uploaded layers.

Can we read that setting and display the value that the user has setup ?

[AllForNothing]

Can we read that setting and display the value that the user has setup ?

@OrlinVasilev No, users can not read it. because we don't want to expose this to the user, but the user can surely override this value in the environment variable:
I think the explanation in the documentation is very clear.
So would it be better to be consistent with the documentation here(say 'a time window(2 hours)')?

[OrlinVasilev]

@AllForNothing can you point me to that part of the documentation where is listed that you can tune that variable ?
So the messaage can be :

Artifacts uploaded in the past 2 hours(the default window) are excluded from garbage collection.

[AllForNothing]

@OrlinVasilev This is not included in our doc.
This should be a part of development instruction(Unfortunately, we don't have it)
Can modify it by below steps
sudo -E make -e down add GC_TIME_WINDOW_HOURS=2 to make/common/config/core/env sudo -E make -e start

[AllForNothing]

@OrlinVasilev @Vad1mo I will update my PR later according to the text 'Artifacts uploaded in the past 2 hours(the default window) are excluded from garbage collection.'

[OrlinVasilev]

@AllForNothing by simple search looks like there are not many other env variables that we use to tune some services.
In that case I think we have to mention that somewhere otherwise it's super well hidden, and it doesn't make sense to have it configurable if we are not providing the way to configure it :)

[wy65701436]

@Vad1mo @OrlinVasilev The original intention of this tooltip is to inform users that the garbage collector will not remove deleted artifacts within the specified time window, which is set to 2 hours by default. This is done to prevent any potential damage to artifacts that are currently being uploaded. Many users do not read the official documentation and often inquire about this behavior.

Regarding the tuning aspect, it was not originally intended for users to customize. Instead, it was primarily designed for debugging purposes. In other words, if a user sets the tuning value to 0 (disabled), it may cause issues in concurrent scenarios where the GC could potentially disrupt the pushing of artifacts. This pushing process is a critical pathway within the registry. So, in any of production environment, we don't recommend user to reset it. If we would like to doc it, @AllForNothing please file another issue specifically addressing this matter. Let's keep the review focused on the wording of the tooltip.

@AllForNothing My suggestion is to inform the user about the existing 2-hour time window in the GC(required) and provide a brief explanation of its purpose(optional). However, for more detailed information on why we have implemented this time window, we recommend referring to the documentation.

[OrlinVasilev]

lgtm