Add selectable fields to gameserver crd

[swermin]

What type of PR is this?

Uncomment only one /kind <> line, press enter to put that in a new line, and remove leading whitespace from that line:

/kind breaking
/kind bug
/kind cleanup
/kind documentation

/kind feature

/kind hotfix
/kind release

What this PR does / Why we need it:
We have observers to make sure that our servers are being in the right state. Since we are running with multi servers it is hard to find specific servers with fields like status and nodeName. So, to facilitate the filtering we wanted to add those fields as selectable.

Special notes for your reviewer:
This is a nice to have feature, to be able to filter based on fields like state and node name.

[lacroixthomas]

Hello !
You might need to run make gen-install, this will update the ./install/yaml/install.yaml

[swermin]

Ah, good point! Let me do that

[lacroixthomas]

/gcbrun

[markmandel]

Is there any limit on the number of selectable fields we can apply?

[swermin]

Is there any limit on the number of selectable fields we can apply?

I don’t think so. What do you have in mind?

[lacroixthomas]

Seems that there is indeed a limitation of 8 selectable fields per CRD: https://pkg.go.dev/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1#CustomResourceDefinitionVersion

// selectableFields specifies paths to fields that may be used as field selectors.
	// A maximum of 8 selectable fields are allowed.
	// See https://kubernetes.io/docs/concepts/overview/working-with-objects/field-selectors
	//
	// +featureGate=CustomResourceFieldSelectors
	// +optional
	// +listType=atomic
	SelectableFields [][SelectableField](https://pkg.go.dev/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1#SelectableField) `json:"selectableFields,omitempty" protobuf:"bytes,9,rep,name=selectableFields"`

Might not be an issue, but we can keep an eye on it, I guess these selectable fields makes sense ?

[markmandel]

I thought I read that there was a limit!

[lacroixthomas]

I thought I read that there was a limit!

And you were right 😄

[markmandel]

I don't have any issues with these fields - but we should be careful with what we pick.

[agones-bot]

Build Succeeded 🥳

Build Id: 29903f9c-f2fe-4012-9b70-99c9de2f1bc6

The following development artifacts have been built, and will exist for the next 30 days:

• image: us-docker.pkg.dev/agones-images/ci/agones-controller:1.58.0-dev-e3d0054
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.58.0-dev-e3d0054
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.58.0-dev-e3d0054-linux
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.58.0-dev-e3d0054
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.58.0-dev-e3d0054
• image: us-docker.pkg.dev/agones-images/ci/agones-processor:1.58.0-dev-e3d0054
• Linux C++ SDK (build): agonessdk-1.58.0-dev-e3d0054-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.58.0-dev-e3d0054.zip

A preview of the website (the last 30 builds are retained):

• https://e3d0054-dot-preview-dot-agones-images.appspot.com/

To install this version:

git fetch https://github.com/googleforgames/agones.git pull/4542/head:pr_4542 && git checkout pr_4542
helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.58.0-dev-e3d0054

[swermin]

Seems that there is indeed a limitation of 8 selectable fields per CRD:

I cannot seem to read the manual 🤣

[swermin]

I don't have any issues with these fields - but we should be careful with what we pick.

I get that. These fields would help us make our maintenance cycle simpler, but that doesn’t mean that it is a right choice to put in here.
I defer to your judgement here if you want to merge it or not.

Our gameservers (for now) do not support signals. So we have safe-to-evict: false set.
Currently when maintenance is needed on a node then we need to use a combination ofawk + sed to figure out which Ready gameservers to delete and let the Allocated one’s drain normally.

These selectors would make is so that we can run a more simple command, like:

Kubectl delete gs —field-selector status.state=Ready,status.nodeName=a-node-name

[markmandel]

I have a fun idea - why not make selected fields helm configurable, and we can default to the two you have selected already.

We don't use them internally, and that way, anyone can change them should they need to.

WDYT?

[swermin]

I was actually wondering if that was possible. Because it would make sense to give the option for others to set the ones they need (if needed that is)

[swermin]

I’ll do some tinkering!

[swermin]

I am also fine to keep the selectable fields empty if that is preferred!

[markmandel]

/gcbrun

Love it.

Thinking about docs.

We'll definitely need docs here: https://agones.dev/site/docs/installation/install-agones/helm/#gameservers

But wondering where to put that fields are selectable in the docs -- maybe in here? https://agones.dev/site/docs/reference/gameserver/ ?

[agones-bot]

Build Succeeded 🥳

Build Id: ce0a1c5f-8861-4e04-a822-c7b9442e823c

The following development artifacts have been built, and will exist for the next 30 days:

• image: us-docker.pkg.dev/agones-images/ci/agones-controller:1.58.0-dev-f1d2062
• image: us-docker.pkg.dev/agones-images/ci/agones-extensions:1.58.0-dev-f1d2062
• image: us-docker.pkg.dev/agones-images/ci/agones-sdk:1.58.0-dev-f1d2062-linux
• image: us-docker.pkg.dev/agones-images/ci/agones-ping:1.58.0-dev-f1d2062
• image: us-docker.pkg.dev/agones-images/ci/agones-allocator:1.58.0-dev-f1d2062
• image: us-docker.pkg.dev/agones-images/ci/agones-processor:1.58.0-dev-f1d2062
• Linux C++ SDK (build): agonessdk-1.58.0-dev-f1d2062-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.58.0-dev-f1d2062.zip

A preview of the website (the last 30 builds are retained):

• https://f1d2062-dot-preview-dot-agones-images.appspot.com/

To install this version:

git fetch https://github.com/googleforgames/agones.git pull/4542/head:pr_4542 && git checkout pr_4542
helm install agones ./install/helm/agones --namespace agones-system --set agones.image.registry=us-docker.pkg.dev/agones-images/ci --set agones.image.tag=1.58.0-dev-f1d2062