feat: Organizational RunnerDeployment Autoscaling

Enhances #57 to add support for organizational runners.

As GitHub Actions does not have an appropriate API for this, this is the spec you need:

```
apiVersion: actions.summerwind.dev/v1alpha1
kind: RunnerDeployment
metadata:
  name: myrunners
spec:
  minReplicas: 1
  maxReplicas: 3
  autoscaling:
    metrics:
    - type: TotalNumberOfQueuedAndProgressingWorkflowRuns
      repositories:
      # Assumes that you have `github.com/myorg/myrepo1` repo
      - myrepo1
      - myrepo2
  template:
    spec:
      organization: myorg
```

It works by collecting "in_progress" and "queued" workflow runs for the repositories `myrepo1` and `myrepo2` to autoscale the number of replicas, assuming you have this organizational runner deployment only for those two repositories.

For example, if `myrepo1` had 1 `in_progress` and 2 `queued` workflow runs, and `myrepo2` had 4 `in_progress` and 8 `queued` workflow runs at the time of running the reconcilation loop on the runner deployment, it will scale replicas to 1 + 2 + 4 + 8 = 15.

Perhaps we might be better add a kind of "ratio" setting so that you can configure the controller to create e.g. 2x runners than demanded. But that's another story.

Ref #10

controllers/autoscaling_test.go

@@ -119,20 +119,6 @@ func TestDetermineDesiredReplicas_RepositoryRunner(t *testing.T) {
 			fixed: intPtr(3),
 			want:  3,
 		},
-		// org runner, fixed at 3
-		{
-			org:   "test",
-			fixed: intPtr(3),
-			want:  3,
-		},
-		// org runner, 1 demanded, min at 1
-		{
-			org:          "test",
-			min:          intPtr(1),
-			max:          intPtr(3),
-			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
-			err:          "Autoscaling is currently supported only when spec.repository is set",
-		},
 	}
 
 	for i := range testcases {
@@ -197,3 +183,189 @@ func TestDetermineDesiredReplicas_RepositoryRunner(t *testing.T) {
 		})
 	}
 }
+
+func TestDetermineDesiredReplicas_OrganizationalRunner(t *testing.T) {
+	intPtr := func(v int) *int {
+		return &v
+	}
+
+	metav1Now := metav1.Now()
+	testcases := []struct {
+		repos        []string
+		org          string
+		fixed        *int
+		max          *int
+		min          *int
+		sReplicas    *int
+		sTime        *metav1.Time
+		workflowRuns string
+		want         int
+		err          string
+	}{
+		// 3 demanded, max at 3
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// 2 demanded, max at 3, currently 3, delay scaling down due to grace period
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			sReplicas:    intPtr(3),
+			sTime:        &metav1Now,
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         3,
+		},
+		// 3 demanded, max at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(2),
+			workflowRuns: `{"total_count": 4, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 2 demanded, min at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 3, "workflow_runs":[{"status":"queued"}, {"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"queued"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 2
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(2),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         2,
+		},
+		// 1 demanded, min at 1
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"queued"}, {"status":"completed"}]}"`,
+			want:         1,
+		},
+		// 1 demanded, min at 1
+		{
+			org:          "test",
+			repos:        []string{"valid"},
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			want:         1,
+		},
+		// fixed at 3
+		{
+			org:   "test",
+			repos: []string{"valid"},
+			fixed: intPtr(3),
+			want:  3,
+		},
+		// org runner, fixed at 3
+		{
+			org:   "test",
+			fixed: intPtr(3),
+			want:  3,
+		},
+		// org runner, 1 demanded, min at 1, no repos
+		{
+			org:          "test",
+			min:          intPtr(1),
+			max:          intPtr(3),
+			workflowRuns: `{"total_count": 2, "workflow_runs":[{"status":"in_progress"}, {"status":"completed"}]}"`,
+			err:          "validating autoscaling metrics: spec.autoscaling.metrics[].repositoryNames is required and must have one more more entries for organizational runner deployment",
+		},
+	}
+
+	for i := range testcases {
+		tc := testcases[i]
+
+		log := zap.New(func(o *zap.Options) {
+			o.Development = true
+		})
+
+		scheme := runtime.NewScheme()
+		_ = clientgoscheme.AddToScheme(scheme)
+		_ = v1alpha1.AddToScheme(scheme)
+
+		t.Run(fmt.Sprintf("case %d", i), func(t *testing.T) {
+			server := fake.NewServer(fake.WithListRepositoryWorkflowRunsResponse(200, tc.workflowRuns))
+			defer server.Close()
+			client := newGithubClient(server)
+
+			r := &RunnerDeploymentReconciler{
+				Log:          log,
+				GitHubClient: client,
+				Scheme:       scheme,
+			}
+
+			rd := v1alpha1.RunnerDeployment{
+				TypeMeta: metav1.TypeMeta{},
+				Spec: v1alpha1.RunnerDeploymentSpec{
+					Template: v1alpha1.RunnerTemplate{
+						Spec: v1alpha1.RunnerSpec{
+							Organization: tc.org,
+						},
+					},
+					Autoscaling: v1alpha1.AutoscalingSpec{
+						Metrics: []v1alpha1.MetricSpec{
+							{
+								Type:            v1alpha1.AutoscalingMetricTypeTotalNumberOfQueuedAndProgressingWorkflowRuns,
+								RepositoryNames: tc.repos,
+							},
+						},
+					},
+					Replicas:    tc.fixed,
+					MaxReplicas: tc.max,
+					MinReplicas: tc.min,
+				},
+				Status: v1alpha1.RunnerDeploymentStatus{
+					Replicas:                   tc.sReplicas,
+					LastSuccessfulScaleOutTime: tc.sTime,
+				},
+			}
+
+			rs, err := r.newRunnerReplicaSetWithAutoscaling(rd)
+			if err != nil {
+				if tc.err == "" {
+					t.Fatalf("unexpected error: expected none, got %v", err)
+				} else if err.Error() != tc.err {
+					t.Fatalf("unexpected error: expected %v, got %v", tc.err, err)
+				}
+				return
+			}
+
+			got := rs.Spec.Replicas
+
+			if got == nil {
+				t.Fatalf("unexpected value of rs.Spec.Replicas: nil")
+			}
+
+			if *got != tc.want {
+				t.Errorf("%d: incorrect desired replicas: want %d, got %d", i, tc.want, *got)
+			}
+		})
+	}
+}