Multiple fixes (#29)

* Multiple fixes

- add goreleaser to the build / release process
- add kubectl plugin for job graphs visualization
- add installation scripts
- update dependencies

* Update the release & CRD content.

* Next set of improvements.

  Code Quality

  - Label constants: Added LabelWorkflowName, LabelGroupName, LabelJobName, LabelJobID in controllers/definitions.go
  - Removed commented debug code: Cleaned up dead code from multiple files
  - Removed unused dependencyTree field: Cleaned connPackage struct
  - Fixed snake_case variables: Changed to camelCase (runGroup, groupDep, runJob, jobDep, k8sJob)

  Kubernetes Best Practices

  - Finalizers: Implemented handleDeletion() and deleteChildJobs() for proper cleanup
  - Status enum validation: Added +kubebuilder:validation:Enum=pending;running;succeeded;failed;aborted
  - ImagePullPolicy default: Created getImagePullPolicy() helper that defaults to IfNotPresent
  - Resource limits support: Added Resources *corev1.ResourceRequirements to ManagedJobParameters

  Observability

  - Prometheus metrics: Created controllers/metrics.go with counters (jobs created/succeeded/failed), histogram (reconciliation duration), and gauge (active jobs)
  - Structured logging: Added logger field to connPackage, used context-based logging throughout

  Configuration

  - Leader election ID: Made configurable via --leader-election-id flag
  - Development mode: Made configurable via --dev-mode flag and LOG_LEVEL env var

  Performance

  - Dependency lookup optimization: Changed from O(n*m) to O(1) using lookup maps (jobDepMap, groupDepMap)
  - Reconciliation backoff: Added RequeueAfter: 30*time.Second when workflow is running

  Documentation & Testing

  - Godoc documentation: Added comprehensive comments to API types and controller
  - Unit tests: Added helpers_test.go with tests for all helper functions
  - Integration tests: Added managedjob_controller_test.go with Ginkgo/Gomega tests

* Add the helm chart release.

* Add reasonable test coverage.

controllers/metrics.go

@@ -0,0 +1,85 @@
+package controllers
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
+)
+
+var (
+	// JobsCreatedTotal tracks the total number of jobs created
+	JobsCreatedTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "managedjob_jobs_created_total",
+			Help: "Total number of Kubernetes jobs created by the operator",
+		},
+		[]string{"namespace", "workflow", "group"},
+	)
+
+	// JobsSucceededTotal tracks the total number of jobs that succeeded
+	JobsSucceededTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "managedjob_jobs_succeeded_total",
+			Help: "Total number of jobs that completed successfully",
+		},
+		[]string{"namespace", "workflow", "group"},
+	)
+
+	// JobsFailedTotal tracks the total number of jobs that failed
+	JobsFailedTotal = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "managedjob_jobs_failed_total",
+			Help: "Total number of jobs that failed",
+		},
+		[]string{"namespace", "workflow", "group"},
+	)
+
+	// ReconciliationDuration tracks how long reconciliations take
+	ReconciliationDuration = prometheus.NewHistogramVec(
+		prometheus.HistogramOpts{
+			Name:    "managedjob_reconciliation_duration_seconds",
+			Help:    "Time spent reconciling ManagedJob resources",
+			Buckets: prometheus.ExponentialBuckets(0.001, 2, 15), // 1ms to ~16s
+		},
+		[]string{"namespace", "workflow"},
+	)
+
+	// ActiveJobs tracks the number of currently running jobs per workflow
+	ActiveJobs = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "managedjob_active_jobs",
+			Help: "Number of currently active (running) jobs per workflow",
+		},
+		[]string{"namespace", "workflow"},
+	)
+)
+
+func init() {
+	// Register custom metrics with the controller-runtime metrics registry
+	metrics.Registry.MustRegister(
+		JobsCreatedTotal,
+		JobsSucceededTotal,
+		JobsFailedTotal,
+		ReconciliationDuration,
+		ActiveJobs,
+	)
+}
+
+// RecordJobCreated increments the job created counter
+func RecordJobCreated(namespace, workflow, group string) {
+	JobsCreatedTotal.WithLabelValues(namespace, workflow, group).Inc()
+}
+
+// RecordJobSucceeded increments the job succeeded counter
+func RecordJobSucceeded(namespace, workflow, group string) {
+	JobsSucceededTotal.WithLabelValues(namespace, workflow, group).Inc()
+}
+
+// RecordJobFailed increments the job failed counter
+func RecordJobFailed(namespace, workflow, group string) {
+	JobsFailedTotal.WithLabelValues(namespace, workflow, group).Inc()
+}
+
+// SetActiveJobs sets the number of active jobs for a workflow
+func SetActiveJobs(namespace, workflow string, count float64) {
+	ActiveJobs.WithLabelValues(namespace, workflow).Set(count)
+}