[cozystack-scheduler] Add custom scheduler as an optional system package

## What this PR does

Adds the cozystack-scheduler as an optional system package, vendored from
https://github.com/cozystack/cozystack-scheduler. The scheduler extends
the default kube-scheduler with SchedulingClass-aware affinity plugins,
allowing platform operators to define cluster-wide scheduling constraints
via a SchedulingClass CRD. Pods opt in via the
`scheduler.cozystack.io/scheduling-class` annotation.

The package includes:
- Helm chart with RBAC, ConfigMap, Deployment, and CRD
- PackageSource definition for the cozystack package system
- Optional inclusion in the platform system bundle

### Release note

```release-note
[cozystack-scheduler] Add cozystack-scheduler as an optional system
package. The custom scheduler supports SchedulingClass CRDs for
cluster-wide node affinity, pod affinity, and topology spread constraints.
```

Signed-off-by: Timofei Larkin <lllamnyp@gmail.com>

packages/core/platform/sources/cozystack-scheduler.yaml

@@ -0,0 +1,19 @@
+---
+apiVersion: cozystack.io/v1alpha1
+kind: PackageSource
+metadata:
+  name: cozystack.cozystack-scheduler
+spec:
+  sourceRef:
+    kind: OCIRepository
+    name: cozystack-packages
+    namespace: cozy-system
+    path: /
+  variants:
+  - name: default
+    components:
+    - name: cozystack-scheduler
+      path: system/cozystack-scheduler
+      install:
+        namespace: kube-system
+        releaseName: cozystack-scheduler

packages/core/platform/templates/bundles/system.yaml

@@ -155,5 +155,6 @@
 {{include "cozystack.platform.package.default" (list "cozystack.bootbox" $) }}
 {{- end }}
 {{include "cozystack.platform.package.optional.default" (list "cozystack.hetzner-robotlb" $) }}
+{{include "cozystack.platform.package.optional.default" (list "cozystack.cozystack-scheduler" $) }}
 
 {{- end }}

packages/system/cozystack-scheduler/Chart.yaml

@@ -0,0 +1,3 @@
+apiVersion: v2
+name: cozy-cozystack-scheduler
+version: 0.1.0

packages/system/cozystack-scheduler/Makefile

@@ -0,0 +1,10 @@
+export NAME=cozystack-scheduler
+export NAMESPACE=kube-system
+
+include ../../../hack/package.mk
+
+update:
+	rm -rf crds templates values.yaml Chart.yaml
+	tag=$$(git ls-remote --tags --sort="v:refname" https://github.com/cozystack/cozystack-scheduler | awk -F'[/^]' 'END{print $$3}') && \
+	curl -sSL https://github.com/cozystack/cozystack-scheduler/archive/refs/tags/$${tag}.tar.gz | \
+	tar xzvf - --strip 2 cozystack-scheduler-$${tag#*v}/chart

packages/system/cozystack-scheduler/templates/clusterrole.yaml

@@ -0,0 +1,9 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: cozystack-scheduler
+rules:
+  - apiGroups: ["cozystack.io"]
+    resources:
+      - schedulingclasses
+    verbs: ["get", "list", "watch"]

packages/system/cozystack-scheduler/templates/clusterrolebinding.yaml

@@ -0,0 +1,38 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: cozystack-scheduler:kube-scheduler
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: system:kube-scheduler
+subjects:
+  - kind: ServiceAccount
+    name: cozystack-scheduler
+    namespace: {{ .Release.Namespace }}
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: cozystack-scheduler:volume-scheduler
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: system:volume-scheduler
+subjects:
+  - kind: ServiceAccount
+    name: cozystack-scheduler
+    namespace: {{ .Release.Namespace }}
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: cozystack-scheduler
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: cozystack-scheduler
+subjects:
+  - kind: ServiceAccount
+    name: cozystack-scheduler
+    namespace: {{ .Release.Namespace }}

packages/system/cozystack-scheduler/templates/configmap.yaml

@@ -0,0 +1,54 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: cozystack-scheduler-config
+  namespace: {{ .Release.Namespace }}
+data:
+  scheduler-config.yaml: |
+    apiVersion: kubescheduler.config.k8s.io/v1
+    kind: KubeSchedulerConfiguration
+    leaderElection:
+      leaderElect: true
+      resourceNamespace: {{ .Release.Namespace }}
+      resourceName: cozystack-scheduler
+    profiles:
+      - schedulerName: cozystack-scheduler
+        plugins:
+          preFilter:
+            disabled:
+              - name: InterPodAffinity
+              - name: NodeAffinity
+              - name: PodTopologySpread
+            enabled:
+              - name: CozystackInterPodAffinity
+              - name: CozystackNodeAffinity
+              - name: CozystackPodTopologySpread
+              - name: CozystackSchedulingClass
+          filter:
+            disabled:
+              - name: InterPodAffinity
+              - name: NodeAffinity
+              - name: PodTopologySpread
+            enabled:
+              - name: CozystackInterPodAffinity
+              - name: CozystackNodeAffinity
+              - name: CozystackPodTopologySpread
+              - name: CozystackSchedulingClass
+          preScore:
+            disabled:
+              - name: InterPodAffinity
+              - name: NodeAffinity
+              - name: PodTopologySpread
+            enabled:
+              - name: CozystackInterPodAffinity
+              - name: CozystackNodeAffinity
+              - name: CozystackPodTopologySpread
+          score:
+            disabled:
+              - name: InterPodAffinity
+              - name: NodeAffinity
+              - name: PodTopologySpread
+            enabled:
+              - name: CozystackInterPodAffinity
+              - name: CozystackNodeAffinity
+              - name: CozystackPodTopologySpread

packages/system/cozystack-scheduler/templates/deployment.yaml

@@ -0,0 +1,37 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: cozystack-scheduler
+  namespace: {{ .Release.Namespace }}
+spec:
+  replicas: {{ .Values.replicas }}
+  selector:
+    matchLabels:
+      app: cozystack-scheduler
+  template:
+    metadata:
+      labels:
+        app: cozystack-scheduler
+    spec:
+      serviceAccountName: cozystack-scheduler
+      containers:
+        - name: cozystack-scheduler
+          image: {{ .Values.image }}
+          command:
+            - /cozystack-scheduler
+            - --config=/etc/kubernetes/scheduler-config.yaml
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: 10259
+              scheme: HTTPS
+            initialDelaySeconds: 15
+          volumeMounts:
+            - name: config
+              mountPath: /etc/kubernetes/scheduler-config.yaml
+              subPath: scheduler-config.yaml
+              readOnly: true
+      volumes:
+        - name: config
+          configMap:
+            name: cozystack-scheduler-config

packages/system/cozystack-scheduler/templates/rolebinding.yaml

@@ -0,0 +1,40 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: cozystack-scheduler:extension-apiserver-authentication-reader
+  namespace: kube-system
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: extension-apiserver-authentication-reader
+subjects:
+  - kind: ServiceAccount
+    name: cozystack-scheduler
+    namespace: {{ .Release.Namespace }}
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: cozystack-scheduler:leader-election
+  namespace: {{ .Release.Namespace }}
+rules:
+  - apiGroups: ["coordination.k8s.io"]
+    resources: ["leases"]
+    verbs: ["create", "get", "list", "update", "watch"]
+  - apiGroups: ["coordination.k8s.io"]
+    resources: ["leasecandidates"]
+    verbs: ["create", "get", "list", "update", "watch"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: cozystack-scheduler:leader-election
+  namespace: {{ .Release.Namespace }}
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: Role
+  name: cozystack-scheduler:leader-election
+subjects:
+  - kind: ServiceAccount
+    name: cozystack-scheduler
+    namespace: {{ .Release.Namespace }}

packages/system/cozystack-scheduler/templates/serviceaccount.yaml

@@ -0,0 +1,5 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: cozystack-scheduler
+  namespace: {{ .Release.Namespace }}

packages/system/cozystack-scheduler/values.yaml

@@ -0,0 +1,2 @@
+image: ghcr.io/cozystack/cozystack/cozystack-scheduler:v0.1.0@sha256:5f7150c82177478467ff80628acb5a400291aff503364aa9e26fc346d79a73cf
+replicas: 1