feat: implement status reporting on ExporterSet resources

[bennyz]

Add deployment-style status conditions and replica counters to ExporterSet CRs, providing visibility into pod health, exporter availability, and scaling state on every reconcile loop.

depends on #864

tested with:

  go build -o bin/exporter-set-controller cmd/exporter-set-controller/main.go
 ./bin/exporter-set-controller --provisioner=qemu.jumpstarter.dev --health-probe-bind-address=:8082

kubectl apply -f - <<'EOF'
  apiVersion: virtualtarget.jumpstarter.dev/v1alpha1
  kind: VirtualTargetClass
  metadata:
    name: qemu-test
    namespace: jumpstarter
  spec:
    provisioner: qemu.jumpstarter.dev
    bindingMode: Immediate
    reclaimPolicy: Delete
  ---
  apiVersion: virtualtarget.jumpstarter.dev/v1alpha1
  kind: ExporterSet
  metadata:
    name: test-set
    namespace: jumpstarter
  spec:
    minReplicas: 2
    maxReplicas: 4
    minAvailableReplicas: 1
    virtualTargetClassName: qemu-test
    selector:
      matchLabels:
        exporterset: test-set
    template:
      metadata:
        labels:
          exporterset: test-set
  EOF

kubectl apply -f - <<EOF
  apiVersion: jumpstarter.dev/v1alpha1
  kind: Exporter
  metadata:
    name: exp-1
    namespace: jumpstarter
    labels:
      exporterset: test-set
    ownerReferences:
    - apiVersion: virtualtarget.jumpstarter.dev/v1alpha1
      kind: ExporterSet
      name: test-set
      uid: "$ES_UID"
      controller: true
      blockOwnerDeletion: true
  spec:
    enabled: true
  ---
  apiVersion: jumpstarter.dev/v1alpha1
  kind: Exporter
  metadata:
    name: exp-2
    namespace: jumpstarter
    labels:
      exporterset: test-set
    ownerReferences:
    - apiVersion: virtualtarget.jumpstarter.dev/v1alpha1
      kind: ExporterSet
      name: test-set
      uid: "$ES_UID"
      controller: true
      blockOwnerDeletion: true
  spec:
    enabled: true
  ---
  apiVersion: jumpstarter.dev/v1alpha1
  kind: Exporter
  metadata:
    name: exp-3
    namespace: jumpstarter
    labels:
      exporterset: test-set
    ownerReferences:
    - apiVersion: virtualtarget.jumpstarter.dev/v1alpha1
      kind: ExporterSet
      name: test-set
      uid: "$ES_UID"
      controller: true
      blockOwnerDeletion: true
  spec:
    enabled: true
  ---
  apiVersion: jumpstarter.dev/v1alpha1
  kind: Exporter
  metadata:
    name: exp-4
    namespace: jumpstarter
    labels:
      exporterset: test-set
    ownerReferences:
    - apiVersion: virtualtarget.jumpstarter.dev/v1alpha1
      kind: ExporterSet
      name: test-set
      uid: "$ES_UID"
      controller: true
      blockOwnerDeletion: true
  spec:
    enabled: false
  EOF

  # exp-1: online, idle
  kubectl patch exporter exp-1 -n jumpstarter --type=merge --subresource=status -p '{
    "status": {
      "conditions": [{"type":"Online","status":"True","lastTransitionTime":"2026-07-21T13:00:00Z","reason":"Connected","message":"connected"}]
    }
  }'

  # exp-2: online, leased
  kubectl patch exporter exp-2 -n jumpstarter --type=merge --subresource=status -p '{
    "status": {
      "conditions": [{"type":"Online","status":"True","lastTransitionTime":"2026-07-21T13:00:00Z","reason":"Connected","message":"connected"}],
      "leaseRef": {"name": "test-lease"}
    }
  }'

  # exp-3: offline
  kubectl patch exporter exp-3 -n jumpstarter --type=merge --subresource=status -p '{
    "status": {
      "conditions": [{"type":"Online","status":"False","lastTransitionTime":"2026-07-21T13:00:00Z","reason":"Disconnected","message":"offline"}]
    }
  }'

  # exp-4: online but disabled
  kubectl patch exporter exp-4 -n jumpstarter --type=merge --subresource=status -p '{
    "status": {
      "conditions": [{"type":"Online","status":"True","lastTransitionTime":"2026-07-21T13:00:00Z","reason":"Connected","message":"connected"}]
    }
  }'

kubectl get exporterset -n jumpstarter -o wide
NAME       REPLICAS   READY   AVAILABLE   UNAVAILABLE   LEASED   CLASS
test-set   4          3       1           1             1        qemu-test

kubectl get events -n jumpstarter --field-selector involvedObject.name=test-set
LAST SEEN   TYPE      REASON                 OBJECT                 MESSAGE
18m         Warning   ExporterSetDegraded    exporterset/test-set   ExporterSet test-set is degraded: 0 failed pods, 1 unavailable replicas
18m         Warning   ScalingLimited         exporterset/test-set   ExporterSet test-set scaling limited at 4 replicas
18m         Normal    ScalingUnlimited       exporterset/test-set   ExporterSet test-set scaling no longer limited
18m         Normal    ExporterSetAvailable   exporterset/test-set   ExporterSet test-set is available: 2 ready replicas
18m         Normal    ExporterSetRecovered   exporterset/test-set   ExporterSet test-set recovered: all replicas healthy
18m         Warning   ExporterSetDegraded    exporterset/test-set   ExporterSet test-set is degraded: 1 failed pods, 1 unavailable replicas

[coderabbitai]

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly summarizes the main change: ExporterSet status reporting.
Description check	✅ Passed	The description matches the changeset by describing status conditions, replica counters, and reconcile-loop updates.

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

controller/internal/exporterset/reconciler.go (1)

475-481: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Replace the deprecated requeue path
Result.Requeue is deprecated in controller-runtime v0.21. Return the conflict error here instead so the standard rate-limited retry path applies.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@controller/internal/exporterset/reconciler.go` around lines 475 - 481, Update
requeueConflict to return the original conflict error instead of
ctrl.Result{Requeue: true}, while preserving the conflict log message and
standard result shape so controller-runtime’s rate-limited retry path handles
it.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@controller/internal/exporterset/reconciler.go`:
- Around line 153-158: Update the status selector assignment in the reconciler
after metav1.LabelSelectorAsSelector succeeds: use the parsed selector’s
String() value for es.Status.Selector instead of
metav1.FormatLabelSelector(&es.Spec.Selector), preserving the existing
validation and error handling.

---

Nitpick comments:
In `@controller/internal/exporterset/reconciler.go`:
- Around line 475-481: Update requeueConflict to return the original conflict
error instead of ctrl.Result{Requeue: true}, while preserving the conflict log
message and standard result shape so controller-runtime’s rate-limited retry
path handles it.

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Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

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Plan: Pro

Run ID: af5dc1f8-1586-490b-a0d2-1856ac710cc2

📥 Commits

Reviewing files that changed from the base of the PR and between 3aaaa70 and aeee053.

📒 Files selected for processing (4)

• controller/api/virtualtarget/v1alpha1/exporterset_types.go
• controller/deploy/operator/config/crd/bases/virtualtarget.jumpstarter.dev_exportersets.yaml
• controller/internal/exporterset/reconciler.go
• controller/internal/exporterset/reconciler_test.go

[kirkbrauer]

I think this looks good, WDYT @mangelajo ?

[bkhizgiy]

looking at the way we calculate the different fields, it looks like available and idle will always hold the same value that represents exporters that are online, enabled, and not leased. given that, do we actually need both fields in the status? AvailableReplicas and ExportersIdle.

[bennyz]

I have thought about it and ultimately decided to keep it to allow repurposing, but I don't mind either way