feat: add outOfTree plugin entry when initializing scheduler

[kerthcet]

Signed-off-by: kerthcet kerthcet@gmail.com

What type of PR is this?
/kind feature

What this PR does / why we need it:

Which issue(s) this PR fixes:
Fixes #1371

Special notes for your reviewer:
Now we can initialize OutOfTree Plugin like below, then we can compile customized karmada scheduler.

command := app.NewSchedulerCommand(stopChan,
    app.WithPlugin(apiinstalled.Name, apiinstalled.New),
)

Does this PR introduce a user-facing change?:

`karmada-scheduler`: People are now able to extend plugins in an out-of-tree mode.

[kerthcet]

I was try to add e2e test, but didn't find any place to change the configuration in initializing scheduler.

[kerthcet]

cc @huone1

[kerthcet]

I was try to add e2e test, but didn't find any place to change the configuration in initializing scheduler.

Sorry for the long delayed response, out of bandwidth in the past weeks. Can you help me with this @huone1 , I would like to add some integration tests or e2e tests. But have no idea how to initialize scheduler in karmada's test framework.

[RainbowMango]

@prodanlabs Is this extension way you are looking for?

[RainbowMango]

@kerthcet Sorry for let this sit, I'll look at it and get back to you(probably next week.)

[kerthcet]

@prodanlabs Is this extension way you are looking for?

FYI, it we merged this, we can extend out-of-tree plugin like below when instantiating the scheduler. Foo is the plugin we'd like to apply.

command := app.NewSchedulerCommand(stopChan,
    app.WithPlugin(Foo.Name, Foo.New),
)

[prodanlabs]

This function is what we need.

Every time you upgrade karmada, you need to recompile karmada-scheduler. It would be better if it can support external expansion. Of course, this can be discussed separately.

[prodanlabs]

@prodanlabs Is this extension way you are looking for?

FYI, it we merged this, we can extend out-of-tree plugin like below when instantiating the scheduler. Foo is the plugin we'd like to apply.

command := app.NewSchedulerCommand(stopChan,
    app.WithPlugin(Foo.Name, Foo.New),
)

Hi @kerthcet ,still need to hardcode, right?

[kerthcet]

@prodanlabs Is this extension way you are looking for?

FYI, it we merged this, we can extend out-of-tree plugin like below when instantiating the scheduler. Foo is the plugin we'd like to apply.

command := app.NewSchedulerCommand(stopChan,
    app.WithPlugin(Foo.Name, Foo.New),
)

Hi @kerthcet ,still need to hardcode, right?

Yes, you have to compile yourself. Here's another way the kubernetes community is looking for, but still exploring. kubernetes/kubernetes#100723

[prodanlabs]

@prodanlabs Is this extension way you are looking for?

FYI, it we merged this, we can extend out-of-tree plugin like below when instantiating the scheduler. Foo is the plugin we'd like to apply.

command := app.NewSchedulerCommand(stopChan,
    app.WithPlugin(Foo.Name, Foo.New),
)

Hi @kerthcet ,still need to hardcode, right?

Yes, you have to compile yourself. Here's another way the kubernetes community is looking for, but still exploring. kubernetes/kubernetes#100723

Thanks.

[RainbowMango]

Thanks @kerthcet and sorry again for letting this sit so long.

/lgtm
/approve

[karmada-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: RainbowMango

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[RainbowMango]

Note: I added a release note to the PR description, this is a significant feature that should be present in the next releases.