Refactor graph and configuration into separate packages

- Move graph-related types and functions to state/graph package. Those
are further split into Gateway resource-related file like httproute.go
- Move configuration-related types and functions to state/dataplane
package
- Add package docs for both packages.

internal/events/handler.go

@@ -13,6 +13,8 @@ import (
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/nginx/file"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/nginx/runtime"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/dataplane"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/secrets"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/status"
 )
 
@@ -30,9 +32,9 @@ type EventHandlerConfig struct {
 	// Processor is the state ChangeProcessor.
 	Processor state.ChangeProcessor
 	// SecretStore is the state SecretStore.
-	SecretStore state.SecretStore
+	SecretStore secrets.SecretStore
 	// SecretMemoryManager is the state SecretMemoryManager.
-	SecretMemoryManager state.SecretDiskMemoryManager
+	SecretMemoryManager secrets.SecretDiskMemoryManager
 	// Generator is the nginx config Generator.
 	Generator config.Generator
 	// NginxFileMgr is the file Manager for nginx.
@@ -88,7 +90,7 @@ func (h *EventHandlerImpl) HandleEventBatch(ctx context.Context, batch EventBatc
 	h.cfg.StatusUpdater.Update(ctx, statuses)
 }
 
-func (h *EventHandlerImpl) updateNginx(ctx context.Context, conf state.Configuration) error {
+func (h *EventHandlerImpl) updateNginx(ctx context.Context, conf dataplane.Configuration) error {
 	// Write all secrets (nuke and pave).
 	// This will remove all secrets in the secrets directory before writing the requested secrets.
 	// FIXME(kate-osborn): We may want to rethink this approach in the future and write and remove secrets individually.

internal/events/handler_test.go

@@ -20,6 +20,8 @@ import (
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/nginx/file/filefakes"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/nginx/runtime/runtimefakes"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/dataplane"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/secrets/secretsfakes"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/statefakes"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/status/statusfakes"
 )
@@ -40,15 +42,15 @@ var _ = Describe("EventHandler", func() {
 	var (
 		handler                 *events.EventHandlerImpl
 		fakeProcessor           *statefakes.FakeChangeProcessor
-		fakeSecretStore         *statefakes.FakeSecretStore
-		fakeSecretMemoryManager *statefakes.FakeSecretDiskMemoryManager
+		fakeSecretStore         *secretsfakes.FakeSecretStore
+		fakeSecretMemoryManager *secretsfakes.FakeSecretDiskMemoryManager
 		fakeGenerator           *configfakes.FakeGenerator
 		fakeNginxFileMgr        *filefakes.FakeManager
 		fakeNginxRuntimeMgr     *runtimefakes.FakeManager
 		fakeStatusUpdater       *statusfakes.FakeUpdater
 	)
 
-	expectReconfig := func(expectedConf state.Configuration, expectedCfg []byte, expectedStatuses state.Statuses) {
+	expectReconfig := func(expectedConf dataplane.Configuration, expectedCfg []byte, expectedStatuses state.Statuses) {
 		Expect(fakeProcessor.ProcessCallCount()).Should(Equal(1))
 
 		Expect(fakeGenerator.GenerateCallCount()).Should(Equal(1))
@@ -68,8 +70,8 @@ var _ = Describe("EventHandler", func() {
 
 	BeforeEach(func() {
 		fakeProcessor = &statefakes.FakeChangeProcessor{}
-		fakeSecretMemoryManager = &statefakes.FakeSecretDiskMemoryManager{}
-		fakeSecretStore = &statefakes.FakeSecretStore{}
+		fakeSecretMemoryManager = &secretsfakes.FakeSecretDiskMemoryManager{}
+		fakeSecretStore = &secretsfakes.FakeSecretStore{}
 		fakeGenerator = &configfakes.FakeGenerator{}
 		fakeNginxFileMgr = &filefakes.FakeManager{}
 		fakeNginxRuntimeMgr = &runtimefakes.FakeManager{}
@@ -91,7 +93,7 @@ var _ = Describe("EventHandler", func() {
 		DescribeTable(
 			"A batch with one event",
 			func(e interface{}) {
-				fakeConf := state.Configuration{}
+				fakeConf := dataplane.Configuration{}
 				fakeStatuses := state.Statuses{}
 				changed := true
 				fakeProcessor.ProcessReturns(changed, fakeConf, fakeStatuses)
@@ -256,7 +258,7 @@ var _ = Describe("EventHandler", func() {
 		batch = append(batch, upserts...)
 		batch = append(batch, deletes...)
 
-		fakeConf := state.Configuration{}
+		fakeConf := dataplane.Configuration{}
 		changed := true
 		fakeStatuses := state.Statuses{}
 		fakeProcessor.ProcessReturns(changed, fakeConf, fakeStatuses)

internal/manager/manager.go

@@ -27,6 +27,7 @@ import (
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/relationship"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/resolver"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/secrets"
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/status"
 )
 
@@ -118,8 +119,8 @@ func Start(cfg config.Config) error {
 		}
 	}
 
-	secretStore := state.NewSecretStore()
-	secretMemoryMgr := state.NewSecretDiskMemoryManager(secretsFolder, secretStore)
+	secretStore := secrets.NewSecretStore()
+	secretMemoryMgr := secrets.NewSecretDiskMemoryManager(secretsFolder, secretStore)
 
 	processor := state.NewChangeProcessorImpl(state.ChangeProcessorConfig{
 		GatewayCtlrName:      cfg.GatewayCtlrName,

internal/nginx/config/generator.go

@@ -1,7 +1,7 @@
 package config
 
 import (
-	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/dataplane"
 )
 
 //go:generate go run github.com/maxbrunsfeld/counterfeiter/v6 . Generator
@@ -10,7 +10,7 @@ import (
 // This interface is used for testing purposes only.
 type Generator interface {
 	// Generate generates NGINX configuration from internal representation.
-	Generate(configuration state.Configuration) []byte
+	Generate(configuration dataplane.Configuration) []byte
 }
 
 // GeneratorImpl is an implementation of Generator.
@@ -22,9 +22,9 @@ func NewGeneratorImpl() GeneratorImpl {
 }
 
 // executeFunc is a function that generates NGINX configuration from internal representation.
-type executeFunc func(configuration state.Configuration) []byte
+type executeFunc func(configuration dataplane.Configuration) []byte
 
-func (g GeneratorImpl) Generate(conf state.Configuration) []byte {
+func (g GeneratorImpl) Generate(conf dataplane.Configuration) []byte {
 	var generated []byte
 	for _, execute := range getExecuteFuncs() {
 		generated = append(generated, execute(conf)...)

internal/nginx/config/generator_test.go

@@ -7,48 +7,49 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/nginx/config"
-	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/dataplane"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/graph"
 )
 
 // Note: this test only verifies that Generate() returns a byte array with upstream, server, and split_client blocks.
 // It does not test the correctness of those blocks. That functionality is covered by other tests in this package.
 func TestGenerate(t *testing.T) {
-	bg := state.BackendGroup{
+	bg := graph.BackendGroup{
 		Source:  types.NamespacedName{Namespace: "test", Name: "hr"},
 		RuleIdx: 0,
-		Backends: []state.BackendRef{
+		Backends: []graph.BackendRef{
 			{Name: "test", Valid: true, Weight: 1},
 			{Name: "test2", Valid: true, Weight: 1},
 		},
 	}
 
-	conf := state.Configuration{
-		HTTPServers: []state.VirtualServer{
+	conf := dataplane.Configuration{
+		HTTPServers: []dataplane.VirtualServer{
 			{
 				IsDefault: true,
 			},
 			{
 				Hostname: "example.com",
 			},
 		},
-		SSLServers: []state.VirtualServer{
+		SSLServers: []dataplane.VirtualServer{
 			{
 				IsDefault: true,
 			},
 			{
 				Hostname: "example.com",
-				SSL: &state.SSL{
+				SSL: &dataplane.SSL{
 					CertificatePath: "/etc/nginx/secrets/default",
 				},
 			},
 		},
-		Upstreams: []state.Upstream{
+		Upstreams: []dataplane.Upstream{
 			{
 				Name:      "up",
 				Endpoints: nil,
 			},
 		},
-		BackendGroups: []state.BackendGroup{bg},
+		BackendGroups: []graph.BackendGroup{bg},
 	}
 	generator := config.NewGeneratorImpl()
 	cfg := string(generator.Generate(conf))

internal/nginx/config/servers.go

@@ -9,20 +9,20 @@ import (
 	"sigs.k8s.io/gateway-api/apis/v1beta1"
 
 	"github.com/nginxinc/nginx-kubernetes-gateway/internal/nginx/config/http"
-	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state"
+	"github.com/nginxinc/nginx-kubernetes-gateway/internal/state/dataplane"
 )
 
 var serversTemplate = gotemplate.Must(gotemplate.New("servers").Parse(serversTemplateText))
 
 const rootPath = "/"
 
-func executeServers(conf state.Configuration) []byte {
+func executeServers(conf dataplane.Configuration) []byte {
 	servers := createServers(conf.HTTPServers, conf.SSLServers)
 
 	return execute(serversTemplate, servers)
 }
 
-func createServers(httpServers, sslServers []state.VirtualServer) []http.Server {
+func createServers(httpServers, sslServers []dataplane.VirtualServer) []http.Server {
 	servers := make([]http.Server, 0, len(httpServers)+len(sslServers))
 
 	for _, s := range httpServers {
@@ -36,7 +36,7 @@ func createServers(httpServers, sslServers []state.VirtualServer) []http.Server
 	return servers
 }
 
-func createSSLServer(virtualServer state.VirtualServer) http.Server {
+func createSSLServer(virtualServer dataplane.VirtualServer) http.Server {
 	if virtualServer.IsDefault {
 		return createDefaultSSLServer()
 	}
@@ -51,7 +51,7 @@ func createSSLServer(virtualServer state.VirtualServer) http.Server {
 	}
 }
 
-func createServer(virtualServer state.VirtualServer) http.Server {
+func createServer(virtualServer dataplane.VirtualServer) http.Server {
 	if virtualServer.IsDefault {
 		return createDefaultHTTPServer()
 	}
@@ -62,7 +62,7 @@ func createServer(virtualServer state.VirtualServer) http.Server {
 	}
 }
 
-func createLocations(pathRules []state.PathRule, listenerPort int) []http.Location {
+func createLocations(pathRules []dataplane.PathRule, listenerPort int) []http.Location {
 	lenPathRules := len(pathRules)
 
 	if lenPathRules == 0 {