Dockerfile, Error handling, comments, docker-compose (#2)

Makefile

@@ -1,14 +1,37 @@
-build:
-	go build -o bin/main src/*.go
+# Variables
+BINARY := bin/main
+SOURCES := $(wildcard src/*.go)
 
-build-linux:
-	GOOS=linux go build -o bin/main src/*.go
+# Build for the current platform
+build: $(BINARY)
 
-build-windows:
-	GOOS=windows go build -o bin/main src/*.go
+$(BINARY): $(SOURCES)
+	go build -o $(BINARY) $(SOURCES)
 
-run:
-	go run src/*.go
+# Build for Linux
+build-linux: GOOS := linux
+build-linux: EXTENSION := 
+build-linux: build-cross
 
-flush-cache:
-	go run src/*.go --flush-cache
+# Build for Windows
+build-windows: GOOS := windows
+build-windows: EXTENSION := .exe
+build-windows: build-cross
+
+# Cross-compile for a specific platform (used by build-linux and build-windows)
+build-cross: export GOOS := $(GOOS)
+build-cross: BINARY := $(BINARY)$(EXTENSION)
+build-cross: $(BINARY)
+
+# Run the application
+run: build
+	./$(BINARY)
+
+# Flush cache
+flush-cache: build
+	./$(BINARY) --flush-cache
+
+# Clean up generated files
+.PHONY: clean
+clean:
+	rm -f $(BINARY) $(BINARY).exe

config.example.yml

@@ -1,8 +1,8 @@
-environment: production
-host: 127.0.0.1
+environment: development
+host: 0.0.0.0
 port: 3001
-redis: redis://username:password@127.0.0.1:6379/0
+redis: ${REDIS_URL} # Use an environment variable to define the Redis URL
 cache:
   java_status_duration: 1m
   bedrock_status_duration: 1m
-  icon_duration: 15m
+  icon_duration: 24h

docker-compose.yml

@@ -0,0 +1,36 @@
+version: "3.9"
+
+services:
+  ping-server:
+    build: .
+    image: ping-server
+    ports:
+      - "3001:3001"
+    depends_on:
+      - redis
+    networks:
+      - app_network
+    environment:
+      REDIS_URL: "redis://redis:6379" # Define the Redis URL using the hostname of the Redis service
+    volumes:
+      - type: bind
+        source: ./config.example.yml
+        target: /app/config.yml
+        read_only: true
+
+  redis:
+    image: "redis:latest"
+    command: ["redis-server", "--appendonly", "yes"]
+    ports:
+      - "6379:6379"
+    networks:
+      - app_network
+    volumes:
+      - redis_data:/data
+
+networks:
+  app_network:
+    driver: bridge
+
+volumes:
+  redis_data:

dockerfile

@@ -0,0 +1,40 @@
+# Build stage
+FROM golang:1.18 AS build
+
+WORKDIR /app
+
+# Install required dependencies
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy the source code
+COPY . .
+
+# Build the executable with CGO disabled
+RUN CGO_ENABLED=0 go build -o bin/main src/*.go
+RUN mv config.example.yml ./bin/config.yml
+
+
+#######################
+# Test stage
+FROM build as test
+RUN go test -v ./... 
+
+
+#######################
+# Runtime stage
+
+FROM gcr.io/distroless/base
+
+# Set the working directory
+WORKDIR /app
+
+# Copy the binary from the build stage
+COPY --from=build /app/bin/main  /app/main
+COPY --from=build /app/bin/config.yml  /app/config.yml
+
+# Expose the port the app runs on (replace with your desired port)
+EXPOSE 3001
+
+# Run the app
+CMD ["./main"]

src/config.go

@@ -1,18 +1,22 @@
 package main
 
 import (
+	"errors"
 	"os"
+	"strconv"
 	"time"
 
 	"gopkg.in/yaml.v3"
 )
 
+// CacheConfig contains cache-related settings.
 type CacheConfig struct {
 	JavaStatusDuration    time.Duration `yaml:"java_status_duration" json:"java_status_duration"`
 	BedrockStatusDuration time.Duration `yaml:"bedrock_status_duration" json:"bedrock_status_duration"`
 	IconDuration          time.Duration `yaml:"icon_duration" json:"icon_duration"`
 }
 
+// Config represents the application configuration.
 type Config struct {
 	Environment string      `yaml:"environment"`
 	Host        string      `yaml:"host"`
@@ -21,12 +25,40 @@ type Config struct {
 	Cache       CacheConfig `yaml:"cache"`
 }
 
+// ReadFile reads the configuration from the given file and overrides values using environment variables.
 func (c *Config) ReadFile(file string) error {
 	data, err := os.ReadFile(file)
-
 	if err != nil {
 		return err
 	}
 
-	return yaml.Unmarshal(data, c)
+	if err := yaml.Unmarshal(data, c); err != nil {
+		return err
+	}
+
+	return c.overrideWithEnvVars()
+}
+
+// overrideWithEnvVars overrides configuration values using environment variables.
+func (c *Config) overrideWithEnvVars() error {
+	if env := os.Getenv("ENVIRONMENT"); env != "" {
+		c.Environment = env
+	}
+
+	if host := os.Getenv("HOST"); host != "" {
+		c.Host = host
+	}
+
+	if port := os.Getenv("PORT"); port != "" {
+		portInt, err := strconv.Atoi(port)
+		if err != nil {
+			return errors.New("invalid port value in environment variable")
+		}
+		c.Port = uint16(portInt)
+	}
+	if redisURL := os.Getenv("REDIS_URL"); redisURL != "" {
+		c.Redis = &redisURL
+	}
+
+	return nil
 }

src/main.go

@@ -15,8 +15,7 @@ var (
 	app *fiber.App = fiber.New(fiber.Config{
 		DisableStartupMessage: true,
 		ErrorHandler: func(ctx *fiber.Ctx, err error) error {
-			log.Println(ctx.Request().URI(), err)
-
+			log.Printf("Error: %v - URI: %v\n", err, ctx.Request().URI())
 			return ctx.SendStatus(http.StatusInternalServerError)
 		},
 	})
@@ -25,24 +24,26 @@ var (
 )
 
 func init() {
+	// Read config file
 	if err := config.ReadFile("config.yml"); err != nil {
-		log.Fatal(err)
+		log.Fatalf("Failed to read config file: %v", err)
 	}
 
+	// Get the blocked server list
 	if err := GetBlockedServerList(); err != nil {
-		log.Fatal(err)
+		log.Fatalf("Failed to retrieve EULA blocked servers: %v", err)
 	}
-
 	log.Println("Successfully retrieved EULA blocked servers")
 
+	// Connect to Redis if the config is set
 	if config.Redis != nil {
 		if err := r.Connect(); err != nil {
-			log.Fatal(err)
+			log.Fatalf("Failed to connect to Redis: %v", err)
 		}
-
 		log.Println("Successfully connected to Redis")
 	}
 
+	// Set up middleware
 	app.Use(recover.New(recover.Config{
 		EnableStackTrace: true,
 	}))
@@ -65,5 +66,7 @@ func main() {
 	defer r.Close()
 
 	log.Printf("Listening on %s:%d\n", config.Host, config.Port)
-	log.Fatal(app.Listen(fmt.Sprintf("%s:%d", config.Host, config.Port)))
+	if err := app.Listen(fmt.Sprintf("%s:%d", config.Host, config.Port)); err != nil {
+		log.Fatalf("Failed to start server: %v", err)
+	}
 }

src/redis.go

@@ -2,38 +2,45 @@ package main
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"github.com/go-redis/redis/v8"
 )
 
+const defaultTimeout = 5 * time.Second
+
+// Redis is a wrapper around the Redis client.
 type Redis struct {
 	Client *redis.Client
 }
 
+// Connect establishes a connection to the Redis server using the configuration.
 func (r *Redis) Connect() error {
-	opts, err := redis.ParseURL(*config.Redis)
+	if config.Redis == nil {
+		return errors.New("missing Redis configuration")
+	}
 
+	opts, err := redis.ParseURL(*config.Redis)
 	if err != nil {
 		return err
 	}
 
 	r.Client = redis.NewClient(opts)
 
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
 	defer cancel()
 
 	return r.Client.Ping(ctx).Err()
 }
 
+// Get retrieves the value and TTL for a given key.
 func (r *Redis) Get(key string) ([]byte, time.Duration, error) {
 	if r.Client == nil {
 		return nil, 0, nil
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
 	defer cancel()
 
 	p := r.Client.Pipeline()
@@ -54,30 +61,31 @@ func (r *Redis) Get(key string) ([]byte, time.Duration, error) {
 	return data, ttl.Val(), err
 }
 
+// Set sets the value and TTL for a given key.
 func (r *Redis) Set(key string, value interface{}, ttl time.Duration) error {
 	if r.Client == nil {
 		return nil
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
 	defer cancel()
 
 	return r.Client.Set(ctx, key, value, ttl).Err()
 }
 
+// Increment increments the integer value of a key by 1.
 func (r *Redis) Increment(key string) error {
 	if r.Client == nil {
 		return nil
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
-
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTimeout)
 	defer cancel()
 
 	return r.Client.Incr(ctx, key).Err()
 }
 
+// Close closes the Redis client connection.
 func (r *Redis) Close() error {
 	if r.Client == nil {
 		return nil

src/routes.go

@@ -18,20 +18,24 @@ func init() {
 	app.Use(NotFoundHandler)
 }
 
+// StatisticsResponse is the structure for the response of the statistics route.
 type StatisticsResponse struct {
 	Cache CacheConfig `json:"cache"`
 }
 
+// PingHandler responds with a 200 OK status for simple health checks.
 func PingHandler(ctx *fiber.Ctx) error {
 	return ctx.SendStatus(http.StatusOK)
 }
 
+// StatisticsHandler returns the cache configuration in the response.
 func StatisticsHandler(ctx *fiber.Ctx) error {
 	return ctx.JSON(StatisticsResponse{
 		Cache: config.Cache,
 	})
 }
 
+// JavaStatusHandler returns the status of the Java edition Minecraft server specified in the address parameter.
 func JavaStatusHandler(ctx *fiber.Ctx) error {
 	host, port, err := ParseAddress(ctx.Params("address"), 25565)
 
@@ -58,6 +62,7 @@ func JavaStatusHandler(ctx *fiber.Ctx) error {
 	return ctx.JSON(response)
 }
 
+// BedrockStatusHandler returns the status of the Bedrock edition Minecraft server specified in the address parameter.
 func BedrockStatusHandler(ctx *fiber.Ctx) error {
 	host, port, err := ParseAddress(ctx.Params("address"), 19132)
 
@@ -84,6 +89,7 @@ func BedrockStatusHandler(ctx *fiber.Ctx) error {
 	return ctx.JSON(response)
 }
 
+// IconHandler returns the server icon for the specified Java edition Minecraft server.
 func IconHandler(ctx *fiber.Ctx) error {
 	host, port, err := ParseAddress(ctx.Params("address"), 25565)
 
@@ -106,10 +112,12 @@ func IconHandler(ctx *fiber.Ctx) error {
 	return ctx.Type("png").Send(icon)
 }
 
+// DefaultIconHandler returns the default server icon.
 func DefaultIconHandler(ctx *fiber.Ctx) error {
 	return ctx.Type("png").Send(defaultIcon)
 }
 
+// NotFoundHandler handles requests to routes that do not exist and returns a 404 Not Found status.
 func NotFoundHandler(ctx *fiber.Ctx) error {
 	return ctx.SendStatus(http.StatusNotFound)
 }

src/util.go

@@ -15,19 +15,20 @@ import (
 
 var (
 	//go:embed icon.png
-	defaultIcon     []byte
-	blockedServers  *MutexArray[string] = nil
-	ipAddressRegExp *regexp.Regexp      = regexp.MustCompile(`^\d{1,3}(\.\d{1,3}){3}$`)
+	defaultIcon    []byte
+	blockedServers *MutexArray = nil
+	ipAddressRegex *regexp.Regexp = regexp.MustCompile(`^\d{1,3}(\.\d{1,3}){3}$`)
 )
 
-type MutexArray[K comparable] struct {
-	List  []K
+// MutexArray is a thread-safe array for storing and checking values.
+type MutexArray struct {
+	List  []interface{}
 	Mutex *sync.Mutex
 }
 
-func (m *MutexArray[K]) Has(value K) bool {
+// Has checks if the given value is present in the array.
+func (m *MutexArray) Has(value interface{}) bool {
 	m.Mutex.Lock()
-
 	defer m.Mutex.Unlock()
 
 	for _, v := range m.List {
@@ -39,9 +40,11 @@ func (m *MutexArray[K]) Has(value K) bool {
 	return false
 }
 
+
+
+// GetBlockedServerList fetches the list of blocked servers from Mojang's session server.
 func GetBlockedServerList() error {
 	resp, err := http.Get("https://sessionserver.mojang.com/blockedservers")
-
 	if err != nil {
 		return err
 	}
@@ -53,42 +56,43 @@ func GetBlockedServerList() error {
 	defer resp.Body.Close()
 
 	body, err := io.ReadAll(resp.Body)
-
 	if err != nil {
 		return err
 	}
 
-	blockedServers = &MutexArray[string]{
-		List:  strings.Split(string(body), "\n"),
+	// Convert []string to []interface{}
+	strSlice := strings.Split(string(body), "\n")
+	interfaceSlice := make([]interface{}, len(strSlice))
+	for i, v := range strSlice {
+		interfaceSlice[i] = v
+	}
+
+	blockedServers = &MutexArray{
+		List:  interfaceSlice,
 		Mutex: &sync.Mutex{},
 	}
 
 	return nil
 }
 
+
+
+// IsBlockedAddress checks if the given address is in the blocked servers list.
 func IsBlockedAddress(address string) bool {
 	split := strings.Split(strings.ToLower(address), ".")
-	isIPAddress := ipAddressRegExp.MatchString(address)
+	isIPAddress := ipAddressRegex.MatchString(address)
 
 	for k := range split {
-		newAddress := ""
+		var newAddress string
 
 		switch k {
 		case 0:
-			{
-				newAddress = strings.Join(split, ".")
-
-				break
-			}
+			newAddress = strings.Join(split, ".")
 		default:
-			{
-				if isIPAddress {
-					newAddress = fmt.Sprintf("%s.*", strings.Join(split[0:len(split)-k], "."))
-				} else {
-					newAddress = fmt.Sprintf("*.%s", strings.Join(split[k:], "."))
-				}
-
-				break
+			if isIPAddress {
+				newAddress = fmt.Sprintf("%s.*", strings.Join(split[0:len(split)-k], "."))
+			} else {
+				newAddress = fmt.Sprintf("*.%s", strings.Join(split[k:], "."))
 			}
 		}
 
@@ -103,6 +107,7 @@ func IsBlockedAddress(address string) bool {
 	return false
 }
 
+// ParseAddress extracts the hostname and port from the given address string, and returns the default port if none is provided.
 func ParseAddress(address string, defaultPort uint16) (string, uint16, error) {
 	result := strings.SplitN(address, ":", 2)
 
@@ -115,7 +120,6 @@ func ParseAddress(address string, defaultPort uint16) (string, uint16, error) {
 	}
 
 	port, err := strconv.ParseUint(result[1], 10, 16)
-
 	if err != nil {
 		return "", 0, err
 	}