VPA doesn't accept 1.2Gi in .spec.ResourcePolicy.MinAllowed

[sanposhiho]

Which component are you using?:

vertical-pod-autoscaler

What version of the component are you using?:

Component version: 0.14.0 (provided within GKE clusters)

What k8s version are you using (kubectl version)?:

kubectl version Output

$ kubectl version
WARNING: This version information is deprecated and will be replaced with the output from kubectl version --short.  Use --output=yaml|json to get the full version.
Client Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.1", GitCommit:"4c9411232e10168d7b050c49a1b59f6df9d7ea4b", GitTreeState:"clean", BuildDate:"2023-04-14T13:14:41Z", GoVersion:"go1.20.3", Compiler:"gc", Platform:"darwin/arm64"}
Kustomize Version: v5.0.1
Server Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.12-gke.1115000", GitCommit:"885327b7f1bebce409c843425b4688e3eeed33f4", GitTreeState:"clean", BuildDate:"2024-03-28T09:16:53Z", GoVersion:"go1.21.8 X:boringcrypto", Compiler:"gc", Platform:"linux/amd64"}

What environment is this in?:

GKE

What did you expect to happen?:

VPA accepts 1.2Gi in .spec.ResourcePolicy.MinAllowed

What happened instead?:

It doesn't.

$ kubectl edit vpa awesome-app -n mercari

error: verticalpodautoscalers.autoscaling.k8s.io "awesome-app" could not be patched: admission webhook "gke-vpa.k8s.io" denied the request: MinAllowed: Memory [{{0 0} {0xc070473f80}  BinarySI}] must be a whole number of bytes

How to reproduce it (as minimally and precisely as possible):

Create VPA with MinAllowed with 1.2Gi

Anything else we need to know?:

[sanposhiho]

Also, I don't understand why minAllowed in this test case is "bad minAllowed memory value".

autoscaler/vertical-pod-autoscaler/pkg/admission-controller/resource/vpa/handler_test.go

Lines 177 to 197 in 5ecf37a

	name: "bad minAllowed memory value",
	vpa: vpa_types.VerticalPodAutoscaler{
	Spec: vpa_types.VerticalPodAutoscalerSpec{
	ResourcePolicy: &vpa_types.PodResourcePolicy{
	ContainerPolicies: []vpa_types.ContainerResourcePolicy{
	{
	ContainerName: "loot box",
	MinAllowed: apiv1.ResourceList{
	cpu: resource.MustParse("1m"),
	memory: resource.MustParse("100m"),
	},
	MaxAllowed: apiv1.ResourceList{
	cpu: resource.MustParse("275m"),
	memory: resource.MustParse("500M"),
	},
	},
	},
	},
	},
	},
	expectError: fmt.Errorf("MinAllowed: Memory [%v] must be a whole number of bytes", resource.MustParse("100m")),

[sanposhiho]

/area vertical-pod-autoscaler

[adrianmoisey]

Also, I don't understand why minAllowed in this test case is "bad minAllowed memory value".

I think it's because the input is 100m, where it should be 100M

[adrianmoisey]

I can confirm that this bug exists in VPA 1.1.1.

[adrianmoisey]

It seems as though this issue is related to #4798

[sanposhiho]

I think it's because the input is 100m, where it should be 100M

100m and 100M are different and both are valid memory value.

[voelzmo]

100m is 100 millibytes, which is 0.1 bytes, and the VPA wants (as the error message points out) a whole number of bytes.

The case for 1.2Gi is quite interesting, because if you convert this binary format into (decimal) bytes, you also end up with a fractional amount of bytes

1.2*1024*1024*1024=1288490188.8

My understanding is that internally k8s will also end up converting memory into decimal bytes and can only deal with whole bytes, therefore this validation ensures this. See #4774 for some context.