Implement SDK SetLabel and SetAnnotation functionality

This implements new functions in the SDK:

- SetLabel(key, value) - that lets you set a label on the backing `GameServer`
- SetAnnotation(key, value) - that lets you set an annotation on the backing
`GameServer`

All keys are prefixed with "stable.agones.dev/sdk-" to maintain isolation.

Closes #279

.dockerignore

@@ -0,0 +1,38 @@
+# Copyright 2018 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# project specific
+.*
+.idea
+*.zip
+/release
+bin
+/docs
+*.md
+*.amd64
+
+# Created by .ignore support plugin (hsz.mobi)
+### Go template
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, build with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out

.gitignore

@@ -16,6 +16,7 @@
 !.gitignore
 !.helmignore
 !.gitattributes
+!.dockerignore
 *.iml
 bin
 *.o

build/Makefile

@@ -47,7 +47,7 @@ GCP_CLUSTER_ZONE ?= us-west1-c
 MINIKUBE_PROFILE ?= agones
 
 # Game Server image to use while doing end-to-end tests
-GS_TEST_IMAGE ?= gcr.io/agones-images/udp-server:0.1
+GS_TEST_IMAGE ?= gcr.io/agones-images/udp-server:0.3
 
 # Directory that this Makefile is in.
 mkfile_path := $(abspath $(lastword $(MAKEFILE_LIST)))

docs/sdk_rest_api.md

@@ -62,6 +62,28 @@ Call when the GameServer session is over and it's time to shut down
 $ curl -d "{}" -H "Content-Type: application/json" -X POST http://localhost:59358/shutdown
 ```
 
+### Set Label
+
+Apply a Label with the prefix "stable.agones.dev/sdk-" to the backing `GameServer` metadata. 
+
+See the SDK [SetLabel](../sdks/README.md#setlabelkey-value) documentation for restrictions.
+
+#### Example
+
+```bash
+$ curl -d '{"key": "foo", "value": "bar"}' -H "Content-Type: application/json" -X PUT http://localhost:59358/metadata/label
+```
+
+### Set Annotation
+
+Apply a Annotation with the prefix "stable.agones.dev/sdk-" to the backing `GameServer` metadata
+
+#### Example
+
+```bash
+$ curl -d '{"key": "foo", "value": "bar"}' -H "Content-Type: application/json" -X PUT http://localhost:59358/metadata/annotation
+```
+
 ### GameServer
 
 Call when you want to retrieve the backing `GameServer` configuration details

examples/cpp-simple/server.cc

@@ -59,8 +59,22 @@ int main() {
     std::thread health (doHealth, sdk);
     std::thread watch (watchUpdates, sdk);
 
+    std::cout << "Setting a label" << std::endl;
+    grpc::Status status = sdk->SetLabel("test-label", "test-value");
+    if (!status.ok()) {
+        std::cout << "Could not run SetLabel(): "+ status.error_message() + ". Exiting!" << std::endl;
+        return -1;
+    }
+
+    std::cout << "Setting an annotation" << std::endl;
+    status = sdk->SetAnnotation("test-annotation", "test value");
+    if (!status.ok()) {
+        std::cout << "Could not run SetAnnotation(): "+ status.error_message() + ". Exiting!" << std::endl;
+        return -1;
+    }
+
     std::cout << "Marking server as ready..." << std::endl;
-    grpc::Status status = sdk->Ready();
+    status = sdk->Ready();
     if (!status.ok()) {
         std::cout << "Could not run Ready(): "+ status.error_message() + ". Exiting!" << std::endl;
         return -1;

examples/simple-udp/main.go

@@ -16,16 +16,17 @@
 package main
 
 import (
+	"encoding/json"
 	"flag"
 	"log"
 	"net"
 	"os"
 	"strings"
 	"time"
 
-	"agones.dev/agones/sdks/go"
-	"encoding/json"
 	coresdk "agones.dev/agones/pkg/sdk"
+	"agones.dev/agones/sdks/go"
+	"strconv"
 )
 
 // main starts a UDP server that received 1024 byte sized packets at at time
@@ -67,23 +68,12 @@ func main() {
 func readWriteLoop(conn net.PacketConn, stop chan struct{}, s *sdk.SDK) {
 	b := make([]byte, 1024)
 	for {
-		n, sender, err := conn.ReadFrom(b)
-		if err != nil {
-			log.Fatalf("Could not read from udp stream: %v", err)
-		}
-
-		txt := strings.TrimSpace(string(b[:n]))
-		log.Printf("Received packet from %v: %v", sender.String(), txt)
+		sender, txt := readPacket(conn, b)
 		switch txt {
+
 		// shuts down the gameserver
 		case "EXIT":
-			log.Printf("Received EXIT command. Exiting.")
-			// This tells Agones to shutdown this Game Server
-			shutdownErr := s.Shutdown()
-			if shutdownErr != nil {
-				log.Printf("Could not shutdown")
-			}
-			os.Exit(0)
+			exit(s)
 
 		// turns off the health pings
 		case "UNHEALTHY":
@@ -94,14 +84,46 @@ func readWriteLoop(conn net.PacketConn, stop chan struct{}, s *sdk.SDK) {
 
 		case "WATCH":
 			watchGameServerEvents(s)
-		}
 
-		// echo it back
-		ack := "ACK: " + txt + "\n"
-		if _, err = conn.WriteTo([]byte(ack), sender); err != nil {
-			log.Fatalf("Could not write to udp stream: %v", err)
+		case "LABEL":
+			setLabel(s)
+
+		case "ANNOTATION":
+			setAnnotation(s)
 		}
+
+		ack(conn, sender, txt)
+	}
+}
+
+// readPacket reads a string from the connection
+func readPacket(conn net.PacketConn, b []byte) (net.Addr, string) {
+	n, sender, err := conn.ReadFrom(b)
+	if err != nil {
+		log.Fatalf("Could not read from udp stream: %v", err)
 	}
+	txt := strings.TrimSpace(string(b[:n]))
+	log.Printf("Received packet from %v: %v", sender.String(), txt)
+	return sender, txt
+}
+
+// ack echoes it back, with an ACK
+func ack(conn net.PacketConn, sender net.Addr, txt string) {
+	ack := "ACK: " + txt + "\n"
+	if _, err := conn.WriteTo([]byte(ack), sender); err != nil {
+		log.Fatalf("Could not write to udp stream: %v", err)
+	}
+}
+
+// exit shutdowns the server
+func exit(s *sdk.SDK) {
+	log.Printf("Received EXIT command. Exiting.")
+	// This tells Agones to shutdown this Game Server
+	shutdownErr := s.Shutdown()
+	if shutdownErr != nil {
+		log.Printf("Could not shutdown")
+	}
+	os.Exit(0)
 }
 
 // writes the GameServer name to the connection UDP stream
@@ -138,6 +160,25 @@ func watchGameServerEvents(s *sdk.SDK) {
 	}
 }
 
+// setAnnotation sets a given annotation
+func setAnnotation(s *sdk.SDK) {
+	log.Print("Setting annotation")
+	err := s.SetAnnotation("timestamp", time.Now().UTC().String())
+	if err != nil {
+		log.Fatalf("could not set annotation: %v", err)
+	}
+}
+
+// setLabel sets a given label
+func setLabel(s *sdk.SDK) {
+	log.Print("Setting label")
+	// label values can only be alpha, - and .
+	err := s.SetLabel("timestamp", strconv.FormatInt(time.Now().Unix(), 10))
+	if err != nil {
+		log.Fatalf("could not set label: %v", err)
+	}
+}
+
 // doHealth sends the regular Health Pings
 func doHealth(sdk *sdk.SDK, stop <-chan struct{}) {
 	tick := time.Tick(2 * time.Second)

pkg/gameservers/localsdk.go

@@ -17,6 +17,7 @@ package gameservers
 import (
 	"io"
 	"time"
+	"sync"
 
 	"agones.dev/agones/pkg/sdk"
 	"github.com/pkg/errors"
@@ -50,14 +51,30 @@ var (
 // is being run for local development, and doesn't connect to the
 // Kubernetes cluster
 type LocalSDKServer struct {
-	watchPeriod time.Duration
+	watchPeriod     time.Duration
+	update          chan struct{}
+	updateObservers sync.Map
 }
 
 // NewLocalSDKServer returns the default LocalSDKServer
 func NewLocalSDKServer() *LocalSDKServer {
-	return &LocalSDKServer{
-		watchPeriod: 5 * time.Second,
+	l := &LocalSDKServer{
+		watchPeriod:     5 * time.Second,
+		update:          make(chan struct{}),
+		updateObservers: sync.Map{},
 	}
+
+	go func() {
+		for value := range l.update {
+			logrus.Info("gameserver update received")
+			l.updateObservers.Range(func(observer, _ interface{}) bool {
+				observer.(chan struct{}) <- value
+				return true
+			})
+		}
+	}()
+
+	return l
 }
 
 // Ready logs that the Ready request has been received
@@ -87,6 +104,22 @@ func (l *LocalSDKServer) Health(stream sdk.SDK_HealthServer) error {
 	}
 }
 
+// SetLabel applies a Label to the backing GameServer metadata
+func (l *LocalSDKServer) SetLabel(_ context.Context, kv *sdk.KeyValue) (*sdk.Empty, error) {
+	logrus.WithField("values", kv).Info("Setting label")
+	fixture.ObjectMeta.Labels[metadataPrefix+kv.Key] = kv.Value
+	l.update <- struct{}{}
+	return &sdk.Empty{}, nil
+}
+
+// SetAnnotation applies a Annotation to the backing GameServer metadata
+func (l *LocalSDKServer) SetAnnotation(_ context.Context, kv *sdk.KeyValue) (*sdk.Empty, error) {
+	logrus.WithField("values", kv).Info("Setting annotation")
+	fixture.ObjectMeta.Annotations[metadataPrefix+kv.Key] = kv.Value
+	l.update <- struct{}{}
+	return &sdk.Empty{}, nil
+}
+
 // GetGameServer returns a dummy game server.
 func (l *LocalSDKServer) GetGameServer(context.Context, *sdk.Empty) (*sdk.GameServer, error) {
 	logrus.Info("getting GameServer details")
@@ -96,17 +129,32 @@ func (l *LocalSDKServer) GetGameServer(context.Context, *sdk.Empty) (*sdk.GameSe
 // WatchGameServer will return a dummy GameServer (with no changes), 3 times, every 5 seconds
 func (l *LocalSDKServer) WatchGameServer(_ *sdk.Empty, stream sdk.SDK_WatchGameServerServer) error {
 	logrus.Info("connected to watch GameServer...")
-	times := 3
+	observer := make(chan struct{})
+
+	defer func() {
+		l.updateObservers.Delete(observer)
+		close(observer)
+	}()
+
+	l.updateObservers.Store(observer, true)
+
+	// on connect, send 3 events, as advertised
+	go func() {
+		times := 3
 
-	for i := 0; i < times; i++ {
-		logrus.Info("Sending watched GameServer!")
+		for i := 0; i < times; i++ {
+			logrus.Info("Sending watched GameServer!")
+			l.update <- struct{}{}
+			time.Sleep(l.watchPeriod)
+		}
+	}()
+
+	for range observer {
 		err := stream.Send(fixture)
 		if err != nil {
 			logrus.WithError(err).Error("error sending gameserver")
 			return err
 		}
-
-		time.Sleep(l.watchPeriod)
 	}
 
 	return nil