Add Event Loop (#56)

Author: pleshakov

Makefile

@@ -22,6 +22,10 @@ ifeq (${TARGET},local)
 	CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION} -X main.commit=${GIT_COMMIT} -X main.date=${DATE}" -o $(OUT_DIR)/gateway github.com/nginxinc/nginx-gateway-kubernetes/cmd/gateway
 endif
 
+.PHONY: generate
+generate:
+	go generate ./...
+
 .PHONY: out_dir
 out_dir:
 	mkdir -p $(OUT_DIR)

cmd/gateway/main.go

@@ -5,14 +5,14 @@ import (
 	"os"
 
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/config"
-	"github.com/nginxinc/nginx-gateway-kubernetes/internal/controller"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/manager"
 
 	flag "github.com/spf13/pflag"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 )
 
 const (
-	domain string = "gateway.nginx.org"
+	domain string = "k8s-gateway.nginx.org"
 )
 
 var (
@@ -48,7 +48,7 @@ func main() {
 		"commit", commit,
 		"date", date)
 
-	err := controller.Start(conf)
+	err := manager.Start(conf)
 	if err != nil {
 		logger.Error(err, "Failed to start control loop")
 		os.Exit(1)

deploy/manifests/nginx-gateway.yaml

@@ -19,6 +19,7 @@ rules:
   resources:
   - gatewayclasses
   - gateways
+  - httproutes
   verbs:
   - list
   - watch

examples/cafe-example/cafe-routes.yaml

@@ -0,0 +1,43 @@
+apiVersion: gateway.networking.k8s.io/v1alpha2
+kind: HTTPRoute
+metadata:
+  name: cafe
+spec:
+  hostnames:
+  - "cafe.example.com"
+  rules:
+  - backendRefs:
+    - name: main
+      port: 80
+---
+apiVersion: gateway.networking.k8s.io/v1alpha2
+kind: HTTPRoute
+metadata:
+  name: coffee
+spec:
+  hostnames:
+  - "cafe.example.com"
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /coffee
+    backendRefs:
+    - name: coffee
+      port: 80
+---
+apiVersion: gateway.networking.k8s.io/v1alpha2
+kind: HTTPRoute
+metadata:
+  name: tea
+spec:
+  hostnames:
+  - "cafe.example.com"
+  rules:
+  - matches:
+    - path:
+        type: PathPrefix
+        value: /tea
+    backendRefs:
+    - name: tea
+      port: 80

go.mod

@@ -5,6 +5,7 @@ go 1.17
 require (
 	github.com/go-logr/logr v1.2.0
 	github.com/google/go-cmp v0.5.6
+	github.com/maxbrunsfeld/counterfeiter/v6 v6.4.1
 	github.com/onsi/ginkgo v1.16.5
 	github.com/onsi/ginkgo/v2 v2.1.1
 	github.com/onsi/gomega v1.17.0

go.sum

@@ -364,6 +364,8 @@ github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzp
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 h1:I0XW9+e1XWDxdcEniV4rQAIOPUGDq67JSCiRCgGCZLI=
 github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
+github.com/maxbrunsfeld/counterfeiter/v6 v6.4.1 h1:hZD/8vBuw7x1WqRXD/WGjVjipbbo/HcDBgySYYbrUSk=
+github.com/maxbrunsfeld/counterfeiter/v6 v6.4.1/go.mod h1:DK1Cjkc0E49ShgRVs5jy5ASrM15svSnem3K/hiSGD8o=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/mitchellh/cli v1.0.0/go.mod h1:hNIlj7HEI86fIcpObd7a0FcrxTWetlwJDGcceTlRvqc=
 github.com/mitchellh/go-homedir v1.0.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
@@ -410,6 +412,7 @@ github.com/onsi/gomega v0.0.0-20170829124025-dcabb60a477c/go.mod h1:C1qb7wdrVGGV
 github.com/onsi/gomega v1.7.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
+github.com/onsi/gomega v1.11.0/go.mod h1:azGKhqFUon9Vuj0YmTfLSmx0FUwqXYSTl5re8lQLTUg=
 github.com/onsi/gomega v1.14.0/go.mod h1:cIuvLEne0aoVhAgh/O6ac0Op8WWw9H6eYCriF+tEHG0=
 github.com/onsi/gomega v1.16.0/go.mod h1:HnhC7FXeEQY45zxNK3PPoIUhzk/80Xly9PcubAlGdZY=
 github.com/onsi/gomega v1.17.0 h1:9Luw4uT5HTjHTN8+aNcSThgH1vdXnmdJ8xIfZ4wyTRE=
@@ -460,6 +463,8 @@ github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFR
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
+github.com/sclevine/spec v1.4.0 h1:z/Q9idDcay5m5irkZ28M7PtQM4aOISzOpj4bUPkDee8=
+github.com/sclevine/spec v1.4.0/go.mod h1:LvpgJaFyvQzRvc1kaDs0bulYwzC70PbiYjC4QnFHkOM=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
@@ -657,6 +662,7 @@ golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v
 golang.org/x/net v0.0.0-20210224082022-3d97a244fca7/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
 golang.org/x/net v0.0.0-20210316092652-d523dce5a7f4/go.mod h1:RBQZq4jEuRlivfhVLdyRGr576XBO4/greRjx4P4O3yc=
+golang.org/x/net v0.0.0-20210331212208-0fccb6fa2b5c/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210428140749-89ef3d95e781/go.mod h1:OJAsFXCWl8Ukc7SiCT/9KSuxbyM7479/AVlXFRxuMCk=
 golang.org/x/net v0.0.0-20210520170846-37e1c6afe023/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
@@ -962,8 +968,9 @@ gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLks
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
 gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b h1:QRR6H1YWRnHb4Y/HeNFCTJLFVxaq6wH4YuVdsUOr75U=
+gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/cheggaaa/pb.v1 v1.0.25/go.mod h1:V/YB90LKu/1FcN3WVnfiiE5oMCibMjukxqG/qStrOgw=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=

internal/events/event.go

@@ -0,0 +1,20 @@
+package events
+
+import (
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+// UpsertEvent represents upserting a resource.
+type UpsertEvent struct {
+	// Resource is the resource that is being upserted.
+	Resource client.Object
+}
+
+// DeleteEvent representing deleting a resource.
+type DeleteEvent struct {
+	// NamespacedName is the namespace & name of the deleted resource.
+	NamespacedName types.NamespacedName
+	// Type is the resource type. For example, if the event is for *v1alpha2.HTTPRoute, pass &v1alpha2.HTTPRoute{} as Type.
+	Type client.Object
+}

internal/events/events_suit_test.go

@@ -0,0 +1,13 @@
+package events_test
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestState(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Events Suite")
+}

internal/events/loop.go

@@ -0,0 +1,108 @@
+package events
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/go-logr/logr"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/state"
+	"sigs.k8s.io/gateway-api/apis/v1alpha2"
+)
+
+// EventLoop is the main event loop of the Gateway.
+type EventLoop struct {
+	conf    state.Configuration
+	eventCh <-chan interface{}
+	logger  logr.Logger
+}
+
+// NewEventLoop creates a new EventLoop.
+func NewEventLoop(conf state.Configuration, eventCh <-chan interface{}, logger logr.Logger) *EventLoop {
+	return &EventLoop{
+		conf:    conf,
+		eventCh: eventCh,
+		logger:  logger.WithName("eventLoop"),
+	}
+}
+
+// Start starts the EventLoop.
+// The method will block until the EventLoop stops:
+// - if it stops because of an error, the Start will return the error.
+// - if it stops normally, the Start will return nil.
+func (el *EventLoop) Start(ctx context.Context) error {
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		case e := <-el.eventCh:
+			err := el.handleEvent(e)
+			if err != nil {
+				return err
+			}
+		}
+	}
+}
+
+// TO-DO: think about how to avoid using an interface{} here
+func (el *EventLoop) handleEvent(event interface{}) error {
+	var changes []state.Change
+	var updates []state.StatusUpdate
+	var err error
+
+	switch e := event.(type) {
+	case *UpsertEvent:
+		changes, updates, err = el.propagateUpsert(e)
+	case *DeleteEvent:
+		changes, updates, err = el.propagateDelete(e)
+	default:
+		return fmt.Errorf("unknown event type %T", e)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	el.processChangesAndStatusUpdates(changes, updates)
+
+	return nil
+}
+
+func (el *EventLoop) propagateUpsert(e *UpsertEvent) ([]state.Change, []state.StatusUpdate, error) {
+	switch r := e.Resource.(type) {
+	case *v1alpha2.HTTPRoute:
+		changes, statusUpdates := el.conf.UpsertHTTPRoute(r)
+		return changes, statusUpdates, nil
+	}
+
+	return nil, nil, fmt.Errorf("unknown resource type %T", e.Resource)
+}
+
+func (el *EventLoop) propagateDelete(e *DeleteEvent) ([]state.Change, []state.StatusUpdate, error) {
+	switch e.Type.(type) {
+	case *v1alpha2.HTTPRoute:
+		changes, statusUpdates := el.conf.DeleteHTTPRoute(e.NamespacedName)
+		return changes, statusUpdates, nil
+	}
+
+	return nil, nil, fmt.Errorf("unknown resource type %T", e.Type)
+}
+
+func (el *EventLoop) processChangesAndStatusUpdates(changes []state.Change, updates []state.StatusUpdate) {
+	for _, c := range changes {
+		el.logger.Info("Processing a change",
+			"host", c.Host.Value)
+
+		// TO-DO: This code is temporary. We will remove it once we have a component that processes changes.
+		fmt.Printf("%+v\n", c)
+	}
+
+	for _, u := range updates {
+		// TO-DO: in the next iteration, the update will include the namespace/name of the resource instead of
+		// runtime.Object, so it will be easy to get the resource namespace/name and include it in the log output
+		el.logger.Info("Processing a status update",
+			"gvk", u.Object.GetObjectKind().GroupVersionKind().String())
+
+		// TO-DO: This code is temporary. We will remove it once we have a component that updates statuses.
+		fmt.Printf("%+v\n", u)
+	}
+}