Files
cozystack/internal/gpu/model/refs.go
T
Aleksei Sviridkin 46ff481549 feat(gpu): add the shared GPU placement and budget model
The binder re-checks what admission checked, and cozystack-api shows the
remaining budget a later order is checked against; computing these in
three places would let them disagree. The model is pure, so each caller
builds a snapshot from its own cache.

GPU budgets cap the whole subtree of the tenant that declares them,
walked over the namespace ancestry and independent of the tenant quota
pools. A raw GPU key blocks a class until the same tenant also declares
a GPU key, and then caps claims and raw-name pods together. Pod usage
follows the scheduler's arithmetic, sidecars included, so the binder
never books a unit a raw-name pod holds.

A node serves a class only when it is schedulable, Ready and carries no
NoSchedule or NoExecute taint the class does not tolerate. The
tolerations are the class's, because a claim is bound before the pod
that will use it exists. The unschedulable, not-ready and unreachable
taints are left to the first two checks, and a taint never counts as a
cordon. Gt and Lt tolerations do not count, since the scheduler ignores
them where their feature gate is off.

Template claim names are derived from the VMI and shortened with a hash
when the VMI name leaves no room, so they stay valid subdomains.

Assisted-by: LLM
Signed-off-by: Aleksei Sviridkin <f@lex.la>
2026-10-23 03:40:49 +03:00

106 lines
3.4 KiB
Go

/*
Copyright 2026 The Cozystack Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package model
import (
"bytes"
"crypto/sha256"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"io"
"strconv"
"strings"
"k8s.io/apimachinery/pkg/util/validation"
)
// ClaimRef is one entry of the gpu.AnnotationClaims list on a VMI:
// exactly one of Claim and ClaimTemplate is set.
type ClaimRef struct {
// Claim names a GPUClaim in the VMI's namespace.
Claim string `json:"claim,omitempty"`
ClaimTemplate *ClaimTemplate `json:"claimTemplate,omitempty"`
}
// ClaimTemplate asks for a GPUClaim created at VMI start and deleted
// with the VMI.
type ClaimTemplate struct {
ClassName string `json:"className"`
Count int32 `json:"count"`
}
// ParseClaimRefs reads the gpu.AnnotationClaims value and checks its
// shape. Claim and class names are not checked here; a malformed one is
// refused when the webhook looks it up.
func ParseClaimRefs(s string) ([]ClaimRef, error) {
dec := json.NewDecoder(bytes.NewReader([]byte(s)))
dec.DisallowUnknownFields()
var refs []ClaimRef
if err := dec.Decode(&refs); err != nil {
return nil, fmt.Errorf("parse claim references: %w", err)
}
if _, err := dec.Token(); err != io.EOF {
return nil, errors.New("parse claim references: data after the list")
}
if len(refs) == 0 {
return nil, errors.New("claim references: empty list")
}
seen := map[string]bool{}
for i, r := range refs {
switch {
case (r.Claim == "") == (r.ClaimTemplate == nil):
return nil, fmt.Errorf("claim reference %d: set exactly one of claim and claimTemplate", i)
case r.ClaimTemplate != nil && r.ClaimTemplate.ClassName == "":
return nil, fmt.Errorf("claim reference %d: claimTemplate needs className", i)
case r.ClaimTemplate != nil && r.ClaimTemplate.Count < 1:
return nil, fmt.Errorf("claim reference %d: claimTemplate count must be at least 1", i)
case seen[r.Claim]:
return nil, fmt.Errorf("claim reference %d: claim %s is referenced twice", i, r.Claim)
}
if r.Claim != "" {
seen[r.Claim] = true
}
}
return refs, nil
}
// FormatClaimRefs renders refs as the gpu.AnnotationClaims value.
func FormatClaimRefs(refs []ClaimRef) (string, error) {
b, err := json.Marshal(refs)
if err != nil {
return "", fmt.Errorf("format claim references: %w", err)
}
return string(b), nil
}
// TemplateClaimName names the GPUClaim created for the claimTemplate
// entry at index of a VMI's references, so a repeated admission or a
// recreated VMI finds the same claim. A VMI name too long to take the
// suffix is cut short and followed by a hash of the full name.
func TemplateClaimName(vmi string, index int) string {
suffix := "-gpu-" + strconv.Itoa(index)
if len(vmi)+len(suffix) <= validation.DNS1123SubdomainMaxLength {
return vmi + suffix
}
sum := sha256.Sum256([]byte(vmi))
hash := hex.EncodeToString(sum[:])[:10]
keep := validation.DNS1123SubdomainMaxLength - len(suffix) - len(hash) - 1
return strings.TrimRight(vmi[:keep], "-.") + "-" + hash + suffix
}