initial commit - basic websocket server and db init

.gitignore

@@ -0,0 +1,3 @@
+felt
+mongodb/data/*
+mongodb/.env

LICENSE

@@ -0,0 +1,22 @@
+MIT License
+
+Copyright (c) 2018 Anmol Sethi <hi@nhooyr.io>
+Copyright (c) 2022 Derek Stevens <nilix@nilfm.cc>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

gametable/server.go

@@ -0,0 +1,145 @@
+package gametable
+
+import (
+  "context"
+  "nhooyr.io/websocket"
+  "golang.org/x/time/rate"
+  "io/ioutil"
+  "time"
+  "sync"
+  "net/http"
+  "log"
+  "errors"
+)
+
+type Subscriber struct {
+  msgs chan []byte
+  closeSlow func()
+}
+
+type GameTableServer struct {
+  subscribeMessageBuffer int
+  publishLimiter *rate.Limiter
+  logf func(f string, v ...interface{})
+  serveMux http.ServeMux
+  subscribersLock sync.Mutex
+  subscribers map[*Subscriber]struct{}
+}
+
+func New() *GameTableServer {
+  srvr := &GameTableServer {
+    subscribeMessageBuffer: 16,
+    logf: log.Printf,
+    subscribers: make(map[*Subscriber]struct{}),
+    publishLimiter: rate.NewLimiter(rate.Every(time.Millisecond*100), 8),
+  }
+  srvr.serveMux.Handle("/", http.FileServer(http.Dir("./static")))
+  srvr.serveMux.HandleFunc("/subscribe", srvr.subscribeHandler)
+  srvr.serveMux.HandleFunc("/publish", srvr.publishHandler)
+  
+  return srvr
+}
+
+func (self *GameTableServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+  self.serveMux.ServeHTTP(w, r)
+}
+
+func (self *GameTableServer) subscribeHandler(w http.ResponseWriter, r *http.Request) {
+	c, err := websocket.Accept(w, r, nil)
+	if err != nil {
+		self.logf("%v", err)
+		return
+	}
+	defer c.Close(websocket.StatusInternalError, "")
+
+	err = self.subscribe(r.Context(), c)
+	if errors.Is(err, context.Canceled) {
+		return
+	}
+	if websocket.CloseStatus(err) == websocket.StatusNormalClosure ||
+		websocket.CloseStatus(err) == websocket.StatusGoingAway {
+		return
+	}
+	if err != nil {
+		self.logf("%v", err)
+		return
+	}
+}
+
+func (self *GameTableServer) subscribe(ctx context.Context, c *websocket.Conn) error {
+	ctx = c.CloseRead(ctx)
+
+	s := &Subscriber{
+		msgs: make(chan []byte, self.subscribeMessageBuffer),
+		closeSlow: func() {
+			c.Close(websocket.StatusPolicyViolation, "connection too slow to keep up with messages")
+		},
+	}
+	self.addSubscriber(s)
+	defer self.deleteSubscriber(s)
+
+	for {
+		select {
+		case msg := <-s.msgs:
+			err := writeTimeout(ctx, time.Second*5, c, msg)
+			if err != nil {
+				return err
+			}
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+func (self *GameTableServer) publishHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "POST" {
+		http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
+		return
+	}
+	body := http.MaxBytesReader(w, r.Body, 8192)
+	msg, err := ioutil.ReadAll(body)
+	if err != nil {
+		http.Error(w, http.StatusText(http.StatusRequestEntityTooLarge), http.StatusRequestEntityTooLarge)
+		return
+	}
+
+	self.publish(msg)
+
+	w.WriteHeader(http.StatusAccepted)
+}
+
+func (self *GameTableServer) publish(msg []byte) {
+	self.subscribersLock.Lock()
+	defer self.subscribersLock.Unlock()
+
+  // decode message and store in DB
+
+	self.publishLimiter.Wait(context.Background())
+
+	for s := range self.subscribers {
+		select {
+		case s.msgs <- msg:
+		default:
+			go s.closeSlow()
+		}
+	}
+}
+
+func (self *GameTableServer) addSubscriber(s *Subscriber) {
+	self.subscribersLock.Lock()
+	self.subscribers[s] = struct{}{}
+	self.subscribersLock.Unlock()
+}
+
+func (self *GameTableServer) deleteSubscriber(s *Subscriber) {
+	self.subscribersLock.Lock()
+	delete(self.subscribers, s)
+	self.subscribersLock.Unlock()
+}
+
+func writeTimeout(ctx context.Context, timeout time.Duration, c *websocket.Conn, msg []byte) error {
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+
+	return c.Write(ctx, websocket.MessageText, msg)
+}

go.mod

@@ -0,0 +1,9 @@
+module nilfm.cc/git/felt
+
+go 1.19
+
+require (
+	github.com/klauspost/compress v1.10.3 // indirect
+	golang.org/x/time v0.1.0 // indirect
+	nhooyr.io/websocket v1.8.7 // indirect
+)

go.sum

@@ -0,0 +1,41 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
+github.com/gin-gonic/gin v1.6.3/go.mod h1:75u5sXoLsGZoRN5Sgbi1eraJ4GU3++wFwWzhwvtwp4M=
+github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
+github.com/go-playground/locales v0.13.0/go.mod h1:taPMhCMXrRLJO55olJkUXHZBHCxTMfnGwq/HNwmWNS8=
+github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
+github.com/go-playground/validator/v10 v10.2.0/go.mod h1:uOYAAleCW8F/7oMFd6aG0GOhaH6EGOAJShg8Id5JGkI=
+github.com/gobwas/httphead v0.0.0-20180130184737-2c6c146eadee/go.mod h1:L0fX3K22YWvt/FAX9NnzrNzcI4wNYi9Yku4O0LKYflo=
+github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
+github.com/gobwas/ws v1.0.2/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
+github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
+github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
+github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
+github.com/klauspost/compress v1.10.3 h1:OP96hzwJVBIHYU52pVTI6CczrxPvrGfgqF9N5eTO0Q8=
+github.com/klauspost/compress v1.10.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
+github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
+github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Kysco4FUpU=
+github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
+github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/ugorji/go v1.1.7/go.mod h1:kZn38zHttfInRq0xu/PH0az30d+z6vm202qpg1oXVMw=
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+golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+golang.org/x/time v0.1.0 h1:xYY+Bajn2a7VBmTM5GikTmnK8ZuX8YgnQCqZpbBNtmA=
+golang.org/x/time v0.1.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+nhooyr.io/websocket v1.8.7 h1:usjR2uOr/zjjkVMy0lW+PPohFok7PCow5sDjLgX4P4g=
+nhooyr.io/websocket v1.8.7/go.mod h1:B70DZP8IakI65RVQ51MsWP/8jndNma26DVA/nFSCgW0=

main.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+  "context"
+  "nilfm.cc/git/felt/gametable"
+  "net"
+  "net/http"
+  "os"
+  "os/signal"
+  "time"
+  "log"
+)
+
+func main() {
+	err := run()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run() error {
+	l, err := net.Listen("tcp", os.Args[1])
+	if err != nil {
+		return err
+	}
+	
+	gt := gametable.New()
+	s := &http.Server{
+	 Handler: gt,
+	 ReadTimeout: time.Second * 10,
+	 WriteTimeout: time.Second * 10,
+	}
+	
+	errc := make(chan error, 1)
+	go func() {
+		errc <- s.Serve(l)
+	}()
+
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, os.Interrupt)
+	select {
+	case err := <-errc:
+		log.Printf("failed to serve: %v", err)
+	case sig := <-sigs:
+		log.Printf("terminating: %v", sig)
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
+	defer cancel()
+
+	return s.Shutdown(ctx)
+}

models/models.go

@@ -0,0 +1,25 @@
+package models
+
+import (
+  "time"
+)
+
+type TableKey struct {
+  name: string
+  passcode: string
+}
+
+type DiceRoll struct {
+  faces: uint8
+  roll: uint8[]
+  player: string
+  note: string
+  timestamp: time.Time
+}
+
+type Token struct {
+  id: string
+  spriteUri: string
+  x: int
+  y: int
+}

mongodb/.env.example

@@ -0,0 +1,5 @@
+MONGO_INITDB_ROOT_USERNAME=root
+MONGO_INITDB_ROOT_PASSWORD=not_the_real_password
+MONGO_INITDB_DATABASE=admin
+dbUser=felt_api
+dbPwd=not_the_real_password_either

mongodb/Dockerfile

@@ -0,0 +1,3 @@
+FROM mongo:6.0.2
+
+COPY ./db_init.sh /docker-entrypoint-initdb.d/

mongodb/adapter.go

@@ -0,0 +1,76 @@
+package dbengine
+
+import (
+  "context"
+  "time"
+  "go.mongodb.org/mongo-driver/bson"
+  "go.mongodb.org/mongo-driver/mongo"
+  "go.mongodb.org/mongo-driver/mongo/options"
+  "nilfm.cc/git/felt/models"
+)
+
+interface DbAdapter {
+  Init(mongoUri: string): error
+  
+  CreateTable(table: models.TableKey): error
+  DestroyTable(table: models.TableKey): error
+  
+  InsertDiceRoll(table: models.TableKey, diceRoll: models.DiceRoll): error
+  GetDiceRolls(table: models.TableKey): models.DiceRoll[], error
+  
+  SetMapImageUrl(table: models.TableKey, url: string): error
+  GetMapImageUrl(table: models.TableKey): string, error
+  
+  AddToken(table: models.TableKey, token: models.Token): error
+  RemoveToken(table: models.TableKey, tokenId: string): error
+  ModifyToken(table: models.TableKey, token: models.Token): error
+  GetTokens(table: models.TableKey): models.Token[], error
+}
+
+type DbEngine struct {
+  client: mongo.Client
+}
+
+func (self *DbEngine) Init(mongoUri: string) error {
+  client, err := mongo.NewClient(options.Client().ApplyURI(mongoUri))
+  if err != nil {
+    return err
+  }
+  self.client = client
+  ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
+  
+  err = client.Connect(ctx)
+  if err != nil {
+    return err
+  }
+  defer client.Disconnect(ctx)
+  
+  db := client.Database("felt")
+  
+  err = self.ensureCollections(db)
+  return err
+}
+
+func (self *DbEngine) ensureCollections(db: mongo.Database) error {
+  tables := db.Collection("tables")
+  if tables == nil {
+    createCmd := bson.D{
+      {"create", "tables"},
+      {"clusteredIndex", {
+        {"key", {"name"}},
+        {"unique", true},
+        {"name", "idx_tables_unique_names"}     
+      }}
+    }
+    
+    var createResult bson.M
+    err := db.RunCommand(
+      context.WithTimeout(context.Background(), 10*time.Second),
+      createCmd).Decode(&createResult)
+    
+    if err != nil {
+      return err
+    }
+  }
+  return nil
+}

mongodb/db_init.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+set -e
+
+# dbUser is the userName used from applicatoin code to interact with databases and dbPwd is the password for this user.
+# MONGO_INITDB_ROOT_USERNAME & MONGO_INITDB_ROOT_PASSWORD is the config for db admin.
+# admin user is expected to be already created when this script executes. We use it here to authenticate as admin to create
+# dbUser and databases.
+
+echo ">>>>>>> trying to create database and users"
+if [ -n "${MONGO_INITDB_ROOT_USERNAME:-}" ] && [ -n "${MONGO_INITDB_ROOT_PASSWORD:-}" ] && [ -n "${dbUser:-}" ] && [ -n "${dbPwd:-}" ]; then
+mongosh -u $MONGO_INITDB_ROOT_USERNAME -p $MONGO_INITDB_ROOT_PASSWORD<<EOF
+
+// create DB
+db=db.getSiblingDB('felt');
+use felt;
+
+if (db.system.users.find({user:'$dbUser'}).count()) {
+  return;
+} 
+
+// Create user account the API uses to connect to db
+db.createUser({
+  user:  '$dbUser',
+  pwd: '$dbPwd',
+  roles: [{
+    role: 'readWrite',
+    db: 'felt'
+  }]
+});
+
+// Insert default config options
+db.config.insertOne({
+  _immutable: true
+});
+
+EOF
+else
+    echo "MONGO_INITDB_ROOT_USERNAME,MONGO_INITDB_ROOT_PASSWORD,dbUser and dbPwd must be provided. Some of these are missing, hence exiting database and user creation"
+    exit 403
+fi

mongodb/run.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+if [ "$1" = "build" ]; then
+  docker build -t felt_db ./
+fi
+
+if [ ! -e .env ]; then
+  cp .env.example .env
+fi
+
+docker run -it --rm --env-file .env -p 27017:27017 -v felt_data:/data/db felt_db