implement multigateway controller

Author: rcambrj

…urce-handler/controller/etcd/etcd_env.go …handler/controller/etcd/container_env.gopkg/resource-handler/controller/etcd/etcd_env.go renamed to pkg/resource-handler/controller/etcd/container_env.go pkg/resource-handler/controller/etcd/etcd_env.go renamed to pkg/resource-handler/controller/etcd/container_env.go

@@ -7,10 +7,14 @@ import (
 	corev1 "k8s.io/api/core/v1"
 )
 
-// buildEtcdEnv constructs all environment variables for etcd clustering in
+// buildContainerEnv constructs all environment variables for etcd clustering in
 // StatefulSets. This combines pod identity, etcd config, and cluster peer
 // discovery details.
-func buildEtcdEnv(etcdName, namespace string, replicas int32, serviceName string) []corev1.EnvVar {
+func buildContainerEnv(
+	etcdName, namespace string,
+	replicas int32,
+	serviceName string,
+) []corev1.EnvVar {
 	envVars := make([]corev1.EnvVar, 0)
 
 	// Add pod identity variables from downward API

…handler/controller/etcd/etcd_env_test.go …er/controller/etcd/container_env_test.gopkg/resource-handler/controller/etcd/etcd_env_test.go renamed to pkg/resource-handler/controller/etcd/container_env_test.go pkg/resource-handler/controller/etcd/etcd_env_test.go renamed to pkg/resource-handler/controller/etcd/container_env_test.go

@@ -178,7 +178,7 @@ func TestBuildEtcdClusterPeerList(t *testing.T) {
 	}
 }
 
-func TestBuildEtcdEnv(t *testing.T) {
+func TestBuildContainerEnv(t *testing.T) {
 	tests := map[string]struct {
 		etcdName    string
 		namespace   string
@@ -319,9 +319,9 @@ func TestBuildEtcdEnv(t *testing.T) {
 
 	for name, tc := range tests {
 		t.Run(name, func(t *testing.T) {
-			got := buildEtcdEnv(tc.etcdName, tc.namespace, tc.replicas, tc.serviceName)
+			got := buildContainerEnv(tc.etcdName, tc.namespace, tc.replicas, tc.serviceName)
 			if diff := cmp.Diff(tc.want, got); diff != "" {
-				t.Errorf("BuildEtcdEnv() mismatch (-want +got):\n%s", diff)
+				t.Errorf("BuildContainerEnv() mismatch (-want +got):\n%s", diff)
 			}
 		})
 	}

pkg/resource-handler/controller/etcd/statefulset.go

@@ -84,7 +84,7 @@ func BuildStatefulSet(
 							Name:      "etcd",
 							Image:     image,
 							Resources: etcd.Spec.Resources,
-							Env: buildEtcdEnv(
+							Env: buildContainerEnv(
 								etcd.Name,
 								etcd.Namespace,
 								replicas,

pkg/resource-handler/controller/etcd/statefulset_test.go

@@ -102,7 +102,7 @@ func TestBuildStatefulSet(t *testing.T) {
 									Name:      "etcd",
 									Image:     DefaultImage,
 									Resources: corev1.ResourceRequirements{},
-									Env: buildEtcdEnv(
+									Env: buildContainerEnv(
 										"test-etcd",
 										"default",
 										3,
@@ -211,7 +211,7 @@ func TestBuildStatefulSet(t *testing.T) {
 									Name:      "etcd",
 									Image:     "quay.io/coreos/etcd:v3.5.15",
 									Resources: corev1.ResourceRequirements{},
-									Env: buildEtcdEnv(
+									Env: buildContainerEnv(
 										"etcd-custom",
 										"test",
 										5,
@@ -319,7 +319,7 @@ func TestBuildStatefulSet(t *testing.T) {
 									Name:      "etcd",
 									Image:     DefaultImage,
 									Resources: corev1.ResourceRequirements{},
-									Env: buildEtcdEnv(
+									Env: buildContainerEnv(
 										"test-etcd",
 										"default",
 										3,
@@ -435,7 +435,7 @@ func TestBuildStatefulSet(t *testing.T) {
 									Name:      "etcd",
 									Image:     DefaultImage,
 									Resources: corev1.ResourceRequirements{},
-									Env: buildEtcdEnv(
+									Env: buildContainerEnv(
 										"test-etcd",
 										"default",
 										3,

pkg/resource-handler/controller/multigateway/container_env.go

@@ -0,0 +1,34 @@
+package multigateway
+
+import (
+	corev1 "k8s.io/api/core/v1"
+)
+
+// buildContainerEnv constructs all environment variables for the MultiGateway
+// container.
+func buildContainerEnv() []corev1.EnvVar {
+	envVars := []corev1.EnvVar{
+		{
+			// TODO: get etcd endpoints and forward them to MultiGateway
+			Name:  "ETCD_ENDPOINTS",
+			Value: "",
+		},
+		{
+			// TODO: is there an env var for HTTP port?
+			Name:  "HTTP_PORT",
+			Value: "",
+		},
+		{
+			// TODO: is there an env var for GRPC port?
+			Name:  "GRPC_PORT",
+			Value: "",
+		},
+		{
+			// TODO: is there an env var for Postgres port?
+			Name:  "POSTGRES_PORT",
+			Value: "",
+		},
+	}
+
+	return envVars
+}

pkg/resource-handler/controller/multigateway/deployment.go

@@ -0,0 +1,89 @@
+package multigateway
+
+import (
+	"fmt"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	ctrl "sigs.k8s.io/controller-runtime"
+
+	multigresv1alpha1 "github.com/numtide/multigres-operator/api/v1alpha1"
+	"github.com/numtide/multigres-operator/pkg/resource-handler/controller/metadata"
+)
+
+const (
+	// ComponentName is the component label value for MultiGateway resources
+	ComponentName = "multigateway"
+
+	// DefaultReplicas is the default number of MultiGateway replicas
+	DefaultReplicas int32 = 2
+
+	// DefaultImage is the default etcd container image
+	DefaultImage = "numtide/multigres-operator:latest"
+)
+
+// BuildDeployment creates a Deployment for the Etcd cluster.
+// Returns a deterministic Deployment based on the Etcd spec.
+func BuildDeployment(
+	mg *multigresv1alpha1.MultiGateway,
+	scheme *runtime.Scheme,
+) (*appsv1.Deployment, error) {
+	replicas := DefaultReplicas
+	// TODO: Debatable whether this defaulting makes sense.
+	if mg.Spec.Replicas != nil {
+		replicas = *mg.Spec.Replicas
+	}
+
+	image := DefaultImage
+	if mg.Spec.Image != "" {
+		image = mg.Spec.Image
+	}
+
+	labels := metadata.BuildStandardLabels(mg.Name, ComponentName, mg.Spec.CellName)
+	podLabels := metadata.MergeLabels(labels, mg.Spec.PodLabels)
+
+	deployment := &appsv1.Deployment{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      mg.Name,
+			Namespace: mg.Namespace,
+			Labels:    labels,
+		},
+		Spec: appsv1.DeploymentSpec{
+			Replicas: &replicas,
+			Selector: &metav1.LabelSelector{
+				MatchLabels: labels,
+			},
+			Template: corev1.PodTemplateSpec{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels:      podLabels,
+					Annotations: mg.Spec.PodAnnotations,
+				},
+				Spec: corev1.PodSpec{
+					ServiceAccountName: mg.Spec.ServiceAccountName,
+					ImagePullSecrets:   mg.Spec.ImagePullSecrets,
+					Containers: []corev1.Container{
+						{
+							Name:      "multigateway",
+							Image:     image,
+							Resources: mg.Spec.Resources,
+							Env:       buildContainerEnv(),
+							Ports:     buildContainerPorts(mg),
+						},
+					},
+					Affinity:                  mg.Spec.Affinity,
+					Tolerations:               mg.Spec.Tolerations,
+					NodeSelector:              mg.Spec.NodeSelector,
+					TopologySpreadConstraints: mg.Spec.TopologySpreadConstraints,
+				},
+			},
+		},
+	}
+
+	if err := ctrl.SetControllerReference(mg, deployment, scheme); err != nil {
+		return nil, fmt.Errorf("failed to set controller reference: %w", err)
+	}
+
+	return deployment, nil
+}