Add default and per-controller max-concurrent-reconciles flags (#4626)

Signed-off-by: KR Ravindra <42912207+KR-Ravindra@users.noreply.github.com>

controllers/actions.github.com/options.go

@@ -10,9 +10,25 @@ import (
 // Options is the optional configuration for the controllers, which can be
 // set via command-line flags or environment variables.
 type Options struct {
-	// RunnerMaxConcurrentReconciles is the maximum number of concurrent Reconciles which can be run
-	// by the EphemeralRunnerController.
-	RunnerMaxConcurrentReconciles int
+	// DefaultMaxConcurrentReconciles is the maximum number of concurrent Reconciles
+	// applied to every controller that does not have its own value set below.
+	DefaultMaxConcurrentReconciles int
+
+	// AutoscalingRunnerSetMaxConcurrentReconciles is the maximum number of concurrent Reconciles
+	// which can be run by the AutoscalingRunnerSetController. Zero means DefaultMaxConcurrentReconciles.
+	AutoscalingRunnerSetMaxConcurrentReconciles int
+
+	// AutoscalingListenerMaxConcurrentReconciles is the maximum number of concurrent Reconciles
+	// which can be run by the AutoscalingListenerController. Zero means DefaultMaxConcurrentReconciles.
+	AutoscalingListenerMaxConcurrentReconciles int
+
+	// EphemeralRunnerSetMaxConcurrentReconciles is the maximum number of concurrent Reconciles
+	// which can be run by the EphemeralRunnerSetController. Zero means DefaultMaxConcurrentReconciles.
+	EphemeralRunnerSetMaxConcurrentReconciles int
+
+	// EphemeralRunnerMaxConcurrentReconciles is the maximum number of concurrent Reconciles
+	// which can be run by the EphemeralRunnerController. Zero means DefaultMaxConcurrentReconciles.
+	EphemeralRunnerMaxConcurrentReconciles int
 }
 
 // OptionsWithDefault returns the default options.
@@ -20,10 +36,31 @@ type Options struct {
 // rather than having to correlate those in multiple places.
 func OptionsWithDefault() Options {
 	return Options{
-		RunnerMaxConcurrentReconciles: 2,
+		DefaultMaxConcurrentReconciles: 1,
 	}
 }
 
+// Resolve returns a copy of the options where a DefaultMaxConcurrentReconciles
+// of zero or less is replaced by 1, and every per-controller
+// MaxConcurrentReconciles that is left at zero is replaced by
+// DefaultMaxConcurrentReconciles.
+func (o Options) Resolve() Options {
+	if o.DefaultMaxConcurrentReconciles <= 0 {
+		o.DefaultMaxConcurrentReconciles = 1
+	}
+	orDefault := func(n int) int {
+		if n > 0 {
+			return n
+		}
+		return o.DefaultMaxConcurrentReconciles
+	}
+	o.AutoscalingRunnerSetMaxConcurrentReconciles = orDefault(o.AutoscalingRunnerSetMaxConcurrentReconciles)
+	o.AutoscalingListenerMaxConcurrentReconciles = orDefault(o.AutoscalingListenerMaxConcurrentReconciles)
+	o.EphemeralRunnerSetMaxConcurrentReconciles = orDefault(o.EphemeralRunnerSetMaxConcurrentReconciles)
+	o.EphemeralRunnerMaxConcurrentReconciles = orDefault(o.EphemeralRunnerMaxConcurrentReconciles)
+	return o
+}
+
 type Option func(*controller.Options)
 
 // WithMaxConcurrentReconciles sets the maximum number of concurrent Reconciles which can be run.

controllers/actions.github.com/options_test.go

@@ -0,0 +1,43 @@
+package actionsgithubcom
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestOptionsResolve(t *testing.T) {
+	t.Parallel()
+
+	t.Run("unset per-controller values fall back to the default", func(t *testing.T) {
+		got := OptionsWithDefault().Resolve()
+		assert.Equal(t, 1, got.DefaultMaxConcurrentReconciles)
+		assert.Equal(t, 1, got.AutoscalingRunnerSetMaxConcurrentReconciles)
+		assert.Equal(t, 1, got.AutoscalingListenerMaxConcurrentReconciles)
+		assert.Equal(t, 1, got.EphemeralRunnerSetMaxConcurrentReconciles)
+		assert.Equal(t, 1, got.EphemeralRunnerMaxConcurrentReconciles)
+	})
+
+	t.Run("a default of zero or less is replaced by 1", func(t *testing.T) {
+		for _, n := range []int{0, -1} {
+			opts := Options{DefaultMaxConcurrentReconciles: n}
+			got := opts.Resolve()
+			assert.Equal(t, 1, got.DefaultMaxConcurrentReconciles)
+			assert.Equal(t, 1, got.AutoscalingRunnerSetMaxConcurrentReconciles)
+			assert.Equal(t, 1, got.AutoscalingListenerMaxConcurrentReconciles)
+			assert.Equal(t, 1, got.EphemeralRunnerSetMaxConcurrentReconciles)
+			assert.Equal(t, 1, got.EphemeralRunnerMaxConcurrentReconciles)
+		}
+	})
+
+	t.Run("a changed default applies to every unset controller", func(t *testing.T) {
+		opts := OptionsWithDefault()
+		opts.DefaultMaxConcurrentReconciles = 4
+		opts.EphemeralRunnerMaxConcurrentReconciles = 20
+		got := opts.Resolve()
+		assert.Equal(t, 4, got.AutoscalingRunnerSetMaxConcurrentReconciles)
+		assert.Equal(t, 4, got.AutoscalingListenerMaxConcurrentReconciles)
+		assert.Equal(t, 4, got.EphemeralRunnerSetMaxConcurrentReconciles)
+		assert.Equal(t, 20, got.EphemeralRunnerMaxConcurrentReconciles)
+	})
+}