feat: implement job primitive

docs/primitives.md

@@ -156,6 +156,7 @@ have been applied. This means a single mutation can safely add a container and t
 | `pkg/primitives/statefulset`        | Workload    | [statefulset.md](primitives/statefulset.md)               |
 | `pkg/primitives/replicaset`         | Workload    | [replicaset.md](primitives/replicaset.md)                 |
 | `pkg/primitives/daemonset`          | Workload    | [daemonset.md](primitives/daemonset.md)                   |
+| `pkg/primitives/job`                | Task        | [job.md](primitives/job.md)                               |
 | `pkg/primitives/cronjob`            | Integration | [cronjob.md](primitives/cronjob.md)                       |
 | `pkg/primitives/configmap`          | Static      | [configmap.md](primitives/configmap.md)                   |
 | `pkg/primitives/pdb`                | Static      | [pdb.md](primitives/pdb.md)                               |

docs/primitives/job.md

@@ -0,0 +1,256 @@
+# Job Primitive
+
+The `job` primitive is the framework's built-in task abstraction for managing Kubernetes `Job` resources. It integrates
+fully with the component lifecycle and provides a rich mutation API for managing containers, pod specs, and metadata —
+following the same pod-template mutation pattern as the Deployment primitive.
+
+## Capabilities
+
+| Capability              | Detail                                                                                          |
+| ----------------------- | ----------------------------------------------------------------------------------------------- |
+| **Completion tracking** | Monitors Job conditions and reports `Completed`, `TaskRunning`, `TaskPending`, or `TaskFailing` |
+| **Suspension**          | Sets `spec.suspend=true` or deletes the Job (default); reports `Suspending` / `Suspended`       |
+| **Mutation pipeline**   | Typed editors for metadata, job spec, pod spec, and containers                                  |
+
+## Building a Job Primitive
+
+```go
+import "github.com/sourcehawk/operator-component-framework/pkg/primitives/job"
+
+base := &batchv1.Job{
+    ObjectMeta: metav1.ObjectMeta{
+        Name:      "db-migration",
+        Namespace: owner.Namespace,
+    },
+    Spec: batchv1.JobSpec{
+        Template: corev1.PodTemplateSpec{
+            Spec: corev1.PodSpec{
+                RestartPolicy: corev1.RestartPolicyOnFailure,
+                Containers: []corev1.Container{
+                    {Name: "migrate", Image: "my-app-migration:latest"},
+                },
+            },
+        },
+    },
+}
+
+resource, err := job.NewBuilder(base).
+    WithMutation(MyFeatureMutation(owner.Spec.Version)).
+    Build()
+```
+
+## Mutations
+
+Mutations are the primary mechanism for modifying a `Job` beyond its baseline. Each mutation is a named function that
+receives a `*Mutator` and records edit intent through typed editors.
+
+The `Feature` field controls when a mutation applies. Leaving it nil applies the mutation unconditionally. A feature
+with no version constraints and no `When()` conditions is also always enabled:
+
+```go
+func MyFeatureMutation(version string) job.Mutation {
+    return job.Mutation{
+        Name:    "my-feature",
+        Feature: feature.NewResourceFeature(version, nil), // always enabled
+        Mutate: func(m *job.Mutator) error {
+            // record edits here
+            return nil
+        },
+    }
+}
+```
+
+Mutations are applied in the order they are registered with the builder. If one mutation depends on a change made by
+another, register the dependency first.
+
+### Boolean-gated mutations
+
+Use `When(bool)` to gate a mutation on a runtime condition:
+
+```go
+func TracingMutation(version string, enabled bool) job.Mutation {
+    return job.Mutation{
+        Name:    "tracing",
+        Feature: feature.NewResourceFeature(version, nil).When(enabled),
+        Mutate: func(m *job.Mutator) error {
+            m.EnsureContainerEnvVar(corev1.EnvVar{
+                Name:  "OTEL_EXPORTER_OTLP_ENDPOINT",
+                Value: "http://otel-collector:4317",
+            })
+            return nil
+        },
+    }
+}
+```
+
+### Version-gated mutations
+
+Pass a `[]feature.VersionConstraint` to gate on a semver range:
+
+```go
+var legacyConstraint = mustSemverConstraint("< 2.0.0")
+
+func LegacyMigrationMutation(version string) job.Mutation {
+    return job.Mutation{
+        Name: "legacy-migration-format",
+        Feature: feature.NewResourceFeature(
+            version,
+            []feature.VersionConstraint{legacyConstraint},
+        ),
+        Mutate: func(m *job.Mutator) error {
+            m.EditContainers(selectors.ContainerNamed("migrate"), func(e *editors.ContainerEditor) error {
+                e.EnsureEnvVar(corev1.EnvVar{Name: "MIGRATION_FORMAT", Value: "v1"})
+                return nil
+            })
+            return nil
+        },
+    }
+}
+```
+
+All version constraints and `When()` conditions must be satisfied for a mutation to apply.
+
+## Internal Mutation Ordering
+
+Within a single mutation, edit operations are grouped into categories and applied in a fixed sequence regardless of the
+order they are recorded. This ensures structural consistency across mutations.
+
+| Step | Category                    | What it affects                                                         |
+| ---- | --------------------------- | ----------------------------------------------------------------------- |
+| 1    | Job metadata edits          | Labels and annotations on the `Job` object                              |
+| 2    | JobSpec edits               | Completions, parallelism, backoff limit, deadline, etc.                 |
+| 3    | Pod template metadata edits | Labels and annotations on the pod template                              |
+| 4    | Pod spec edits              | Volumes, tolerations, node selectors, service account, security context |
+| 5    | Regular container presence  | Adding or removing containers from `spec.template.spec.containers`      |
+| 6    | Regular container edits     | Env vars, args, resources (snapshot taken after step 5)                 |
+| 7    | Init container presence     | Adding or removing containers from `spec.template.spec.initContainers`  |
+| 8    | Init container edits        | Env vars, args, resources (snapshot taken after step 7)                 |
+
+Container edits (steps 6 and 8) are evaluated against a snapshot taken _after_ presence operations in the same mutation.
+This means a single mutation can add a container and then configure it without selector resolution issues.
+
+## Editors
+
+### JobSpecEditor
+
+Controls job-level settings via `m.EditJobSpec`.
+
+Available methods: `SetCompletions`, `SetParallelism`, `SetBackoffLimit`, `SetActiveDeadlineSeconds`,
+`SetTTLSecondsAfterFinished`, `SetCompletionMode`, `Raw`.
+
+```go
+m.EditJobSpec(func(e *editors.JobSpecEditor) error {
+    e.SetBackoffLimit(3)
+    e.SetActiveDeadlineSeconds(600)
+    return nil
+})
+```
+
+For fields not covered by the typed API, use `Raw()`:
+
+```go
+m.EditJobSpec(func(e *editors.JobSpecEditor) error {
+    e.Raw().Suspend = ptr.To(true)
+    return nil
+})
+```
+
+### PodSpecEditor
+
+Manages pod-level configuration via `m.EditPodSpec`.
+
+Available methods: `SetServiceAccountName`, `EnsureVolume`, `RemoveVolume`, `EnsureToleration`, `RemoveTolerations`,
+`EnsureNodeSelector`, `RemoveNodeSelector`, `EnsureImagePullSecret`, `RemoveImagePullSecret`, `SetPriorityClassName`,
+`SetHostNetwork`, `SetHostPID`, `SetHostIPC`, `SetSecurityContext`, `Raw`.
+
+```go
+m.EditPodSpec(func(e *editors.PodSpecEditor) error {
+    e.SetServiceAccountName("migration-sa")
+    e.EnsureVolume(corev1.Volume{
+        Name: "config",
+        VolumeSource: corev1.VolumeSource{
+            ConfigMap: &corev1.ConfigMapVolumeSource{
+                LocalObjectReference: corev1.LocalObjectReference{Name: "migration-config"},
+            },
+        },
+    })
+    return nil
+})
+```
+
+### ContainerEditor
+
+Modifies individual containers via `m.EditContainers` or `m.EditInitContainers`. Always used in combination with a
+[selector](../primitives.md#container-selectors).
+
+Available methods: `EnsureEnvVar`, `EnsureEnvVars`, `RemoveEnvVar`, `RemoveEnvVars`, `EnsureArg`, `EnsureArgs`,
+`RemoveArg`, `RemoveArgs`, `SetResourceLimit`, `SetResourceRequest`, `SetResources`, `Raw`.
+
+```go
+m.EditContainers(selectors.ContainerNamed("migrate"), func(e *editors.ContainerEditor) error {
+    e.EnsureEnvVar(corev1.EnvVar{Name: "DB_HOST", Value: "postgres:5432"})
+    e.SetResourceLimit(corev1.ResourceCPU, resource.MustParse("500m"))
+    return nil
+})
+```
+
+### ObjectMetaEditor
+
+Modifies labels and annotations. Use `m.EditObjectMetadata` to target the `Job` object itself, or
+`m.EditPodTemplateMetadata` to target the pod template.
+
+Available methods: `EnsureLabel`, `RemoveLabel`, `EnsureAnnotation`, `RemoveAnnotation`, `Raw`.
+
+```go
+m.EditObjectMetadata(func(e *editors.ObjectMetaEditor) error {
+    e.EnsureLabel("app.kubernetes.io/version", version)
+    return nil
+})
+```
+
+## Convenience Methods
+
+The `Mutator` exposes convenience wrappers that target all containers at once:
+
+| Method                        | Equivalent to                                                 |
+| ----------------------------- | ------------------------------------------------------------- |
+| `EnsureContainerEnvVar(ev)`   | `EditContainers(AllContainers(), ...)` → `EnsureEnvVar(ev)`   |
+| `RemoveContainerEnvVar(name)` | `EditContainers(AllContainers(), ...)` → `RemoveEnvVar(name)` |
+
+## Suspension
+
+Jobs use the Task lifecycle for suspension, which differs from Workloads:
+
+- **Default behavior**: `DefaultDeleteOnSuspendHandler` returns `true`, meaning the Job is deleted from the cluster
+  during suspension.
+- **Suspend mutation**: `DefaultSuspendMutationHandler` sets `spec.suspend=true`, which prevents the Job controller from
+  creating new pods while allowing existing pods to complete.
+- **Suspension status**: `DefaultSuspensionStatusHandler` checks if `spec.suspend=true` and `status.active=0`.
+
+Override any of these via the Builder:
+
+```go
+resource, err := job.NewBuilder(base).
+    WithCustomSuspendDeletionDecision(func(j *batchv1.Job) bool {
+        return false // Keep the Job in the cluster when suspended
+    }).
+    Build()
+```
+
+## Guidance
+
+**`Feature: nil` applies unconditionally.** Omit `Feature` (leave it nil) for mutations that should always run. Use
+`feature.NewResourceFeature(version, constraints)` when version-based gating is needed, and chain `.When(bool)` for
+boolean conditions.
+
+**Register mutations in dependency order.** If mutation B relies on a container added by mutation A, register A first.
+The internal ordering within each mutation handles intra-mutation dependencies automatically.
+
+**Prefer `EnsureContainer` over direct slice manipulation.** The mutator tracks presence operations so that selectors in
+the same mutation resolve correctly and reconciliation remains idempotent.
+
+**Use selectors for precision.** Targeting `AllContainers()` when you only mean to modify the primary container can
+cause unexpected behavior if init containers or sidecar containers are present.
+
+**Jobs are deleted on suspend by default.** Unlike Deployments which scale to zero, Jobs are deleted during suspension.
+Override `WithCustomSuspendDeletionDecision` if you need to keep the Job resource in the cluster.

examples/job-primitive/README.md

@@ -0,0 +1,36 @@
+# Job Primitive Example
+
+This example demonstrates the usage of the `job` primitive within the operator component framework. It shows how to
+manage a Kubernetes Job as a component of a larger application, utilizing features like:
+
+- **Base Construction**: Initializing a Job with basic metadata, spec, and restart policy.
+- **Feature Mutations**: Applying version-gated or conditional changes (env vars, image version, retry policies) using
+  the `Mutator`.
+- **Custom Status Handlers**: Overriding the default `ConvergingStatus` interface using the `WithCustomConvergeStatus`
+  builder option.
+- **Suspension**: Demonstrating how Jobs are suspended (deleted by default) when the component is suspended.
+- **Data Extraction**: Harvesting information from the reconciled resource.
+
+## Directory Structure
+
+- `app/`: Defines the mock `ExampleApp` CRD and the controller that uses the component framework.
+- `features/`: Contains modular feature definitions:
+  - `mutations.go`: tracing env vars, retry policies, and version-based image updates.
+  - `status.go`: implementation of a custom handler for completion status.
+- `resources/`: Contains the central `NewJobResource` factory that assembles all features using the `job.Builder`.
+- `main.go`: A standalone entry point that demonstrates a single reconciliation loop using a fake client.
+
+## Running the Example
+
+You can run this example directly using `go run`:
+
+```bash
+go run examples/job-primitive/main.go
+```
+
+This will:
+
+1. Initialize a fake Kubernetes client.
+2. Create an `ExampleApp` owner object.
+3. Reconcile the `ExampleApp` components through multiple spec changes.
+4. Print the resulting status conditions after each reconciliation step.

examples/job-primitive/app/controller.go

@@ -0,0 +1,54 @@
+// Package app provides a sample controller using the job primitive.
+package app
+
+import (
+	"context"
+
+	"github.com/sourcehawk/operator-component-framework/pkg/component"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/record"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+// ExampleController reconciles an ExampleApp object using the component framework.
+type ExampleController struct {
+	client.Client
+	Scheme   *runtime.Scheme
+	Recorder record.EventRecorder
+	Metrics  component.Recorder
+
+	// NewJobResource is a factory function to create the job resource.
+	// This allows us to inject the resource construction logic.
+	NewJobResource func(*ExampleApp) (component.Resource, error)
+}
+
+// Reconcile performs the reconciliation for a single ExampleApp.
+func (r *ExampleController) Reconcile(ctx context.Context, owner *ExampleApp) error {
+	// 1. Build the job resource for this owner.
+	jobResource, err := r.NewJobResource(owner)
+	if err != nil {
+		return err
+	}
+
+	// 2. Build the component that manages the job.
+	comp, err := component.NewComponentBuilder().
+		WithName("example-migration").
+		WithConditionType("MigrationReady").
+		WithResource(jobResource, component.ResourceOptions{}).
+		Suspend(owner.Spec.Suspended).
+		Build()
+	if err != nil {
+		return err
+	}
+
+	// 3. Execute the component reconciliation.
+	resCtx := component.ReconcileContext{
+		Client:   r.Client,
+		Scheme:   r.Scheme,
+		Recorder: r.Recorder,
+		Metrics:  r.Metrics,
+		Owner:    owner,
+	}
+
+	return comp.Reconcile(ctx, resCtx)
+}

examples/job-primitive/app/owner.go

@@ -0,0 +1,20 @@
+package app
+
+import (
+	sharedapp "github.com/sourcehawk/operator-component-framework/examples/shared/app"
+)
+
+// ExampleApp re-exports the shared CRD type so callers in this package need no import alias.
+type ExampleApp = sharedapp.ExampleApp
+
+// ExampleAppSpec re-exports the shared spec type.
+type ExampleAppSpec = sharedapp.ExampleAppSpec
+
+// ExampleAppStatus re-exports the shared status type.
+type ExampleAppStatus = sharedapp.ExampleAppStatus
+
+// ExampleAppList re-exports the shared list type.
+type ExampleAppList = sharedapp.ExampleAppList
+
+// AddToScheme registers the ExampleApp types with the given scheme.
+var AddToScheme = sharedapp.AddToScheme