Add configuration file and runtime management of NGINX

build/Dockerfile

@@ -11,14 +11,25 @@ RUN go mod download
 COPY cmd /go/src/github.com/nginxinc/nginx-gateway-kubernetes/cmd
 COPY internal /go/src/github.com/nginxinc/nginx-gateway-kubernetes/internal
 COPY pkg /go/src/github.com/nginxinc/nginx-gateway-kubernetes/pkg
-RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION} -X main.commit=${GIT_COMMIT} -X main.date=${DATE}" -o ./build/.out/gateway .
+RUN CGO_ENABLED=0 GOOS=linux go build -trimpath -a -ldflags "-s -w -X main.version=${VERSION} -X main.commit=${GIT_COMMIT} -X main.date=${DATE}" -o gateway .
+
+FROM alpine:3.15 as capabilizer
+RUN apk add --no-cache libcap
+
+FROM capabilizer as local-capabilizer
+COPY ./build/.out/gateway /usr/bin/
+RUN setcap 'cap_kill=+ep' /usr/bin/gateway
+
+FROM capabilizer as container-capabilizer
+COPY --from=builder /go/src/github.com/nginxinc/nginx-gateway-kubernetes/cmd/gateway/gateway /usr/bin/
+RUN setcap 'cap_kill=+ep' /usr/bin/gateway
 
 FROM scratch as common
 USER 1001:1001
 ENTRYPOINT [ "/usr/bin/gateway" ]
 
 FROM common as container
-COPY --from=builder /go/src/github.com/nginxinc/nginx-gateway-kubernetes/cmd/gateway/gateway /usr/bin/
+COPY --from=container-capabilizer /usr/bin/gateway /usr/bin/
 
 FROM common as local
-COPY ./build/.out/gateway /usr/bin/
+COPY --from=local-capabilizer /usr/bin/gateway /usr/bin/

deploy/manifests/nginx-gateway.yaml

@@ -72,21 +72,30 @@ spec:
       labels:
         app: nginx-gateway
     spec:
+      shareProcessNamespace: true
       serviceAccountName: nginx-gateway
       volumes:
       - name: nginx-config
         emptyDir: { }
       initContainers:
-      - image: busybox:1.34
+      - image: busybox:1.34 # FIXME(pleshakov): use gateway container to init the Config with proper main config
         name: nginx-config-initializer
-        command: [ 'sh', '-c', 'echo "events {} http { server { default_type text/plain; return 200 \"hello from \$hostname\n\"; } }" > /etc/nginx/nginx.conf' ]
+        command: [ 'sh', '-c', 'echo "events {}  pid /etc/nginx/nginx.pid; http { include /etc/nginx/conf.d/*.conf; server { default_type text/html; return 404; } }" > /etc/nginx/nginx.conf && mkdir /etc/nginx/conf.d && chown 1001:0 /etc/nginx/conf.d' ]
         volumeMounts:
         - name: nginx-config
           mountPath: /etc/nginx
       containers:
       - image: nginx-gateway:0.0.1
         imagePullPolicy: IfNotPresent
         name: nginx-gateway
+        volumeMounts:
+        - name: nginx-config
+          mountPath: /etc/nginx
+        securityContext:
+          runAsUser: 1001
+          # FIXME(pleshakov) - figure out which capabilities are required
+          # dropping ALL and adding only CAP_KILL doesn't work
+          # Note: CAP_KILL is needed for sending HUP signal to NGINX main process
         args:
         - --gateway-ctlr-name=k8s-gateway.nginx.org/nginx-gateway/gateway
       - image: nginx:1.21.3

internal/events/loop.go

@@ -6,6 +6,8 @@ import (
 
 	"github.com/go-logr/logr"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/config"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/file"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/runtime"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/state"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/status"
 	apiv1 "k8s.io/api/core/v1"
@@ -14,12 +16,14 @@ import (
 
 // EventLoop is the main event loop of the Gateway.
 type EventLoop struct {
-	conf          state.Configuration
-	serviceStore  state.ServiceStore
-	generator     config.Generator
-	eventCh       <-chan interface{}
-	logger        logr.Logger
-	statusUpdater status.Updater
+	conf            state.Configuration
+	serviceStore    state.ServiceStore
+	generator       config.Generator
+	eventCh         <-chan interface{}
+	logger          logr.Logger
+	statusUpdater   status.Updater
+	nginxFileMgr    file.Manager
+	nginxRuntimeMgr runtime.Manager
 }
 
 // NewEventLoop creates a new EventLoop.
@@ -30,14 +34,18 @@ func NewEventLoop(
 	eventCh <-chan interface{},
 	statusUpdater status.Updater,
 	logger logr.Logger,
+	nginxFileMgr file.Manager,
+	nginxRuntimeMgr runtime.Manager,
 ) *EventLoop {
 	return &EventLoop{
-		conf:          conf,
-		serviceStore:  serviceStore,
-		generator:     generator,
-		eventCh:       eventCh,
-		statusUpdater: statusUpdater,
-		logger:        logger.WithName("eventLoop"),
+		conf:            conf,
+		serviceStore:    serviceStore,
+		generator:       generator,
+		eventCh:         eventCh,
+		statusUpdater:   statusUpdater,
+		logger:          logger.WithName("eventLoop"),
+		nginxFileMgr:    nginxFileMgr,
+		nginxRuntimeMgr: nginxRuntimeMgr,
 	}
 }
 
@@ -118,14 +126,8 @@ func (el *EventLoop) processChangesAndStatusUpdates(ctx context.Context, 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)
-
 		if c.Op == state.Upsert {
 			cfg, warnings := el.generator.GenerateForHost(c.Host)
-			// TO-DO: for now, we only print the generated config, without writing it on the file system
-			// and reloading NGINX.
-			fmt.Println(string(cfg))
 
 			for obj, objWarnings := range warnings {
 				for _, w := range objWarnings {
@@ -137,6 +139,28 @@ func (el *EventLoop) processChangesAndStatusUpdates(ctx context.Context, changes
 						"warning", w)
 				}
 			}
+
+			el.logger.Info("Writing configuration",
+				"host", c.Host.Value)
+
+			err := el.nginxFileMgr.WriteServerConfig(c.Host.Value, cfg)
+			if err != nil {
+				el.logger.Error(err, "Failed to write configuration",
+					"host", c.Host.Value)
+			}
+		} else {
+			err := el.nginxFileMgr.DeleteServerConfig(c.Host.Value)
+			if err != nil {
+				el.logger.Error(err, "Failed to delete configuration",
+					"host", c.Host.Value)
+			}
+		}
+	}
+
+	if len(changes) > 0 {
+		err := el.nginxRuntimeMgr.Reload(ctx)
+		if err != nil {
+			el.logger.Error(err, "Failed to reload NGINX")
 		}
 	}
 

internal/events/loop_test.go

@@ -4,7 +4,10 @@ import (
 	"context"
 
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/events"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/config"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/config/configfakes"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/file/filefakes"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/runtime/runtimefakes"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/state"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/state/statefakes"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/status/statusfakes"
@@ -37,6 +40,8 @@ var _ = Describe("EventLoop", func() {
 	var fakeUpdater *statusfakes.FakeUpdater
 	var fakeServiceStore *statefakes.FakeServiceStore
 	var fakeGenerator *configfakes.FakeGenerator
+	var fakeNginxFimeMgr *filefakes.FakeManager
+	var fakeNginxRuntimeMgr *runtimefakes.FakeManager
 	var cancel context.CancelFunc
 	var eventCh chan interface{}
 	var errorCh chan error
@@ -47,7 +52,9 @@ var _ = Describe("EventLoop", func() {
 		fakeUpdater = &statusfakes.FakeUpdater{}
 		fakeServiceStore = &statefakes.FakeServiceStore{}
 		fakeGenerator = &configfakes.FakeGenerator{}
-		ctrl = events.NewEventLoop(fakeConf, fakeServiceStore, fakeGenerator, eventCh, fakeUpdater, zap.New())
+		fakeNginxFimeMgr = &filefakes.FakeManager{}
+		fakeNginxRuntimeMgr = &runtimefakes.FakeManager{}
+		ctrl = events.NewEventLoop(fakeConf, fakeServiceStore, fakeGenerator, eventCh, fakeUpdater, zap.New(), fakeNginxFimeMgr, fakeNginxRuntimeMgr)
 
 		var ctx context.Context
 
@@ -71,8 +78,10 @@ var _ = Describe("EventLoop", func() {
 		It("should process upsert event", func() {
 			fakeChanges := []state.Change{
 				{
-					Op:   state.Upsert,
-					Host: state.Host{},
+					Op: state.Upsert,
+					Host: state.Host{
+						Value: "example.com",
+					},
 				},
 			}
 			fakeStatusUpdates := []state.StatusUpdate{
@@ -83,6 +92,9 @@ var _ = Describe("EventLoop", func() {
 			}
 			fakeConf.UpsertHTTPRouteReturns(fakeChanges, fakeStatusUpdates)
 
+			fakeCfg := []byte("fake")
+			fakeGenerator.GenerateForHostReturns(fakeCfg, config.Warnings{})
+
 			hr := &v1alpha2.HTTPRoute{}
 
 			eventCh <- &events.UpsertEvent{
@@ -102,13 +114,22 @@ var _ = Describe("EventLoop", func() {
 
 			Eventually(fakeGenerator.GenerateForHostCallCount).Should(Equal(1))
 			Expect(fakeGenerator.GenerateForHostArgsForCall(0)).Should(Equal(fakeChanges[0].Host))
+
+			Eventually(fakeNginxFimeMgr.WriteServerConfigCallCount).Should(Equal(1))
+			host, cfg := fakeNginxFimeMgr.WriteServerConfigArgsForCall(0)
+			Expect(host).Should(Equal("example.com"))
+			Expect(cfg).Should(Equal(fakeCfg))
+
+			Eventually(fakeNginxRuntimeMgr.ReloadCallCount).Should(Equal(1))
 		})
 
 		It("should process delete event", func() {
 			fakeChanges := []state.Change{
 				{
-					Op:   state.Delete,
-					Host: state.Host{},
+					Op: state.Delete,
+					Host: state.Host{
+						Value: "example.com",
+					},
 				},
 			}
 			fakeStatusUpdates := []state.StatusUpdate{
@@ -137,9 +158,10 @@ var _ = Describe("EventLoop", func() {
 				return updates
 			}).Should(Equal(fakeStatusUpdates))
 
-			// TO-DO:
-			// once we have a component that processes host deletion, ensure that
-			// its corresponding method is eventually called
+			Eventually(fakeNginxFimeMgr.DeleteServerConfigCallCount).Should(Equal(1))
+			Expect(fakeNginxFimeMgr.DeleteServerConfigArgsForCall(0)).Should(Equal("example.com"))
+
+			Eventually(fakeNginxRuntimeMgr.ReloadCallCount).Should(Equal(1))
 		})
 	})
 
@@ -180,6 +202,58 @@ var _ = Describe("EventLoop", func() {
 		})
 	})
 
+	Describe("Processing events common cases", func() {
+		AfterEach(func() {
+			cancel()
+
+			var err error
+			Eventually(errorCh).Should(Receive(&err))
+			Expect(err).To(BeNil())
+		})
+
+		It("should reload once in case of multiple changes", func() {
+			fakeChanges := []state.Change{
+				{
+					Op: state.Delete,
+					Host: state.Host{
+						Value: "one.example.com",
+					},
+				},
+				{
+					Op: state.Upsert,
+					Host: state.Host{
+						Value: "two.example.com",
+					},
+				},
+			}
+			fakeConf.DeleteHTTPRouteReturns(fakeChanges, nil)
+
+			fakeCfg := []byte("fake")
+			fakeGenerator.GenerateForHostReturns(fakeCfg, config.Warnings{})
+
+			nsname := types.NamespacedName{Namespace: "test", Name: "route"}
+
+			// the exact event doesn't matter. what matters is the generated changes return by DeleteHTTPRouteReturns
+			eventCh <- &events.DeleteEvent{
+				NamespacedName: nsname,
+				Type:           &v1alpha2.HTTPRoute{},
+			}
+
+			Eventually(fakeConf.DeleteHTTPRouteCallCount).Should(Equal(1))
+			Expect(fakeConf.DeleteHTTPRouteArgsForCall(0)).Should(Equal(nsname))
+
+			Eventually(fakeNginxFimeMgr.WriteServerConfigCallCount).Should(Equal(1))
+			host, cfg := fakeNginxFimeMgr.WriteServerConfigArgsForCall(0)
+			Expect(host).Should(Equal("two.example.com"))
+			Expect(cfg).Should(Equal(fakeCfg))
+
+			Eventually(fakeNginxFimeMgr.DeleteServerConfigCallCount).Should(Equal(1))
+			Expect(fakeNginxFimeMgr.DeleteServerConfigArgsForCall(0)).Should(Equal("one.example.com"))
+
+			Eventually(fakeNginxRuntimeMgr.ReloadCallCount).Should(Equal(1))
+		})
+	})
+
 	Describe("Edge cases", func() {
 		AfterEach(func() {
 			cancel()

internal/manager/manager.go

@@ -12,6 +12,8 @@ import (
 	hr "github.com/nginxinc/nginx-gateway-kubernetes/internal/implementations/httproute"
 	svc "github.com/nginxinc/nginx-gateway-kubernetes/internal/implementations/service"
 	ngxcfg "github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/config"
+	"github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/file"
+	ngxruntime "github.com/nginxinc/nginx-gateway-kubernetes/internal/nginx/runtime"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/state"
 	"github.com/nginxinc/nginx-gateway-kubernetes/internal/status"
 	nginxgwv1alpha1 "github.com/nginxinc/nginx-gateway-kubernetes/pkg/apis/gateway/v1alpha1"
@@ -78,7 +80,9 @@ func Start(cfg config.Config) error {
 	serviceStore := state.NewServiceStore()
 	reporter := status.NewUpdater(mgr.GetClient(), cfg.Logger)
 	configGenerator := ngxcfg.NewGeneratorImpl(serviceStore)
-	eventLoop := events.NewEventLoop(conf, serviceStore, configGenerator, eventCh, reporter, cfg.Logger)
+	nginxFileMgr := file.NewManagerImpl()
+	nginxRuntimeMgr := ngxruntime.NewManagerImpl()
+	eventLoop := events.NewEventLoop(conf, serviceStore, configGenerator, eventCh, reporter, cfg.Logger, nginxFileMgr, nginxRuntimeMgr)
 
 	err = mgr.Add(eventLoop)
 	if err != nil {