feat: Auto config reload on file update (#235)

.web/docs/.vitepress/config.ts

@@ -111,28 +111,37 @@ export default defineConfig({
                             link: '/developers/',
                         },
                         {
-                            text: 'Configurations',
-                            link: '/guide/config/',
+                            text: 'Lite Mode',
+                            link: '/guide/lite'
                         },
                         {
                             text: 'Security & DDoS Protection',
                             link: '/guide/security'
                         },
                         {
-                            text: 'Lite Mode',
-                            link: '/guide/lite'
+                            text: 'Compatibility',
+                            link: '/guide/compatibility'
                         },
+                    ]
+                },
+                {
+                    text: 'Configuration',
+                    items: [
                         {
                             text: 'Enabling Connect',
                             link: '/guide/connect'
                         },
                         {
-                            text: 'Builtin Commands',
-                            link: '/guide/builtin-commands'
+                            text: 'Complete Configuration',
+                            link: '/guide/config/',
                         },
                         {
-                            text: 'Compatibility',
-                            link: '/guide/compatibility'
+                            text: 'Auto Reload',
+                            link: '/guide/config/reload',
+                        },
+                        {
+                            text: 'Builtin Commands',
+                            link: '/guide/builtin-commands'
                         },
                         {
                             text: 'Rate Limiting',
@@ -164,6 +173,10 @@ export default defineConfig({
                         },
                     ]
                 },
+                {
+                    text: 'Back to Guides',
+                    link: '/guide/',
+                },
             ],
             // '/config/': [
             //     {

.web/docs/guide/config/reload.md

@@ -0,0 +1,41 @@
+# Auto Config Reload
+
+_Gate watches your file for updates._
+
+---
+
+Gate supports automatic config reloading without restarting the proxy by watching your config file for changes
+without disconnecting players.
+
+This is useful for example when you want to change **any setting in the config** like servers, the motd or
+switch to Lite mode while staying live.
+
+::: tip
+Generally all settings can be changed without disconnecting players,
+however some session-related properties like `online-mode` will only apply to newly connected
+players that joined after the config update and does not kick players that are already connected with another
+online-mode.
+:::
+
+## How it works
+
+Gate watches your config file for changes and reloads it automatically when it detects a change.
+This is seen as a safe operation, as the config is validated before it is applied.
+If it is invalid, the reload is aborted and the proxy continues to run with the last valid config.
+
+## Switching to Lite mode and Connect
+
+If you want to switch to [Lite mode](/guide/lite) or [Connect](/guide/connect), you can do so without restarting the
+proxy.
+This is useful if you want to test it out or if you want to switch to Lite mode temporarily for maintenance
+or migration purposes.
+
+## How to enable it
+
+This feature is always enabled by default, given that you have a config file.
+
+## How to disable it
+
+This can not be disabled.
+If you feel like you need to disable it, please [open an issue](
+https://github.com/minekube/gate/issues/new?title=Disable%20auto%20config%20reload&body=I%20want%20to%20disable%20auto%20config%20reload%20because%20...).

.web/docs/guide/connect.md

@@ -1,8 +1,9 @@
 # Enabling Connect Integration
 
-Gate has a builtin integration with [Connect](https://connect.minekube.com/) to list your proxy on the Connect network.
+Gate has a builtin integration with [Connect](https://connect.minekube.com/) to list your proxy on
+the [Connect network](https://connect.minekube.com/guide/#the-connect-network).
 
-Great side effect is that it exposes your locally running Gate proxy to the Internet
+Great side effect is that it also exposes your locally running Gate proxy to the Internet
 and allows players to connect to it from anywhere using the free provided domain
 `<my-server-name>.play.minekube.net`.
 

cmd/gate/root.go

@@ -1,24 +1,19 @@
 package gate
 
 import (
-	"bytes"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"math"
 	"os"
-	"path"
 	"strings"
 
 	"github.com/go-logr/logr"
 	"github.com/go-logr/zapr"
 	"github.com/spf13/viper"
 	"github.com/urfave/cli/v2"
 	"go.minekube.com/gate/pkg/gate"
-	"go.minekube.com/gate/pkg/gate/config"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
-	"gopkg.in/yaml.v3"
 )
 
 // Execute runs App() and calls os.Exit when finished.
@@ -76,7 +71,12 @@ Visit the website https://gate.minekube.com/ for more information.`
 		// Load config
 		cfg, err := gate.LoadConfig(v)
 		if err != nil {
-			return cli.Exit(err, 1)
+			// A config file is only required to exist when explicit config flag was specified.
+			// Otherwise, we just use the default config.
+			if !(errors.As(err, &viper.ConfigFileNotFoundError{}) || os.IsNotExist(err)) || c.IsSet("config") {
+				err = fmt.Errorf("error reading config file %q: %w", v.ConfigFileUsed(), err)
+				return cli.Exit(err, 2)
+			}
 		}
 
 		// Flags overwrite config
@@ -98,7 +98,10 @@ Visit the website https://gate.minekube.com/ for more information.`
 		log.Info("using config file", "config", v.ConfigFileUsed())
 
 		// Start Gate
-		if err = gate.Start(c.Context, gate.WithConfig(*cfg)); err != nil {
+		if err = gate.Start(c.Context,
+			gate.WithConfig(*cfg),
+			gate.WithAutoConfigReload(v.ConfigFileUsed()),
+		); err != nil {
 			return cli.Exit(fmt.Errorf("error running Gate: %w", err), 1)
 		}
 		return nil
@@ -118,62 +121,9 @@ func initViper(c *cli.Context, configFile string) (*viper.Viper, error) {
 	v.SetEnvPrefix("GATE")
 	v.AutomaticEnv() // read in environment variables that match
 	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
-	// Read in config.
-	cfgCopy := func() config.Config { return config.DefaultConfig }()
-	if err := FixedReadInConfig(v, configFile, &cfgCopy); err != nil {
-		// A config file is only required to exist when explicit config flag was specified.
-		if !(errors.As(err, &viper.ConfigFileNotFoundError{}) || os.IsNotExist(err)) || c.IsSet("config") {
-			return nil, fmt.Errorf("error reading config file %q: %w", v.ConfigFileUsed(), err)
-		}
-	}
 	return v, nil
 }
 
-// FixedReadInConfig is a workaround for https://github.com/minekube/gate/issues/218#issuecomment-1632800775
-func FixedReadInConfig[T any](v *viper.Viper, configFile string, defaultConfig *T) error {
-	if defaultConfig == nil {
-		return v.ReadInConfig()
-	}
-
-	if configFile == "" {
-		// Try to find config file using Viper's config finder logic
-		if err := v.ReadInConfig(); err != nil {
-			return err
-		}
-		configFile = v.ConfigFileUsed()
-		if configFile == "" {
-			return nil // no config file found
-		}
-	}
-
-	var (
-		unmarshal func([]byte, any) error
-		marshal   func(any) ([]byte, error)
-	)
-	switch path.Ext(configFile) {
-	case ".yaml", ".yml":
-		unmarshal = yaml.Unmarshal
-		marshal = yaml.Marshal
-	case ".json":
-		unmarshal = json.Unmarshal
-		marshal = json.Marshal
-	default:
-		return fmt.Errorf("unsupported config file format %q", configFile)
-	}
-	b, err := os.ReadFile(configFile)
-	if err != nil {
-		return fmt.Errorf("error reading config file %q: %w", configFile, err)
-	}
-	if err = unmarshal(b, defaultConfig); err != nil {
-		return fmt.Errorf("error unmarshaling config file %q to %T: %w", configFile, defaultConfig, err)
-	}
-	if b, err = marshal(defaultConfig); err != nil {
-		return fmt.Errorf("error marshaling config file %q: %w", configFile, err)
-	}
-
-	return v.ReadConfig(bytes.NewReader(b))
-}
-
 // newLogger returns a new zap logger with a modified production
 // or development default config to ensure human readability.
 func newLogger(debug bool, v int) (l logr.Logger, err error) {

config-lite.yml

@@ -62,4 +62,4 @@ config:
           version:
             name: §eTry example.com
             protocol: -1
-          favicon: server-icon.png
+          #favicon: server-icon.png

config.yml

@@ -170,7 +170,7 @@ config:
           version:
             name: §eTry example.com
             protocol: -1
-          favicon: server-icon.png
+          #favicon: server-icon.png
 
 # Configuration for Connect, a network that organizes all Minecraft servers/proxies
 # and makes them universally accessible for all players.

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/google/uuid v1.3.0
 	github.com/gookit/color v1.5.4
 	github.com/jellydator/ttlcache/v3 v3.0.1
+	github.com/knadh/koanf/providers/file v0.1.0
 	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646
 	github.com/pires/go-proxyproto v0.7.0
 	github.com/robinbraemer/event v0.0.1
@@ -26,7 +27,6 @@ require (
 	go.minekube.com/common v0.0.5
 	go.minekube.com/connect v0.5.3
 	go.uber.org/atomic v1.11.0
-	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.25.0
 	golang.org/x/sync v0.3.0
 	golang.org/x/text v0.12.0
@@ -64,6 +64,7 @@ require (
 	github.com/subosito/gotenv v1.4.2 // indirect
 	github.com/xo/terminfo v0.0.0-20210125001918-ca9a967f8778 // indirect
 	github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/image v0.9.0 // indirect
 	golang.org/x/sys v0.10.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230726155614-23370e0ffb3e // indirect

go.sum

@@ -223,6 +223,8 @@ github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+o
 github.com/klauspost/compress v1.10.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/klauspost/compress v1.16.7 h1:2mk3MPGNzKyxErAw8YaohYh69+pa4sIQSC0fPGCFR9I=
 github.com/klauspost/compress v1.16.7/go.mod h1:ntbaceVETuRiXiv4DpjP66DpAtAGkEQskQzEyD//IeE=
+github.com/knadh/koanf/providers/file v0.1.0 h1:fs6U7nrV58d3CFAFh8VTde8TM262ObYf3ODrc//Lp+c=
+github.com/knadh/koanf/providers/file v0.1.0/go.mod h1:rjJ/nHQl64iYCtAW2QQnF0eSmDEX/YZ/eNFj5yR6BvA=
 github.com/kr/fs v0.1.0/go.mod h1:FFnZGqtBN9Gxj7eW1uZ42v5BccTP0vu6NEaFoC2HwRg=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=

pkg/edition/java/config/config.go

@@ -4,6 +4,10 @@ import (
 	"fmt"
 
 	liteconfig "go.minekube.com/gate/pkg/edition/java/lite/config"
+	"go.minekube.com/gate/pkg/edition/java/proto/version"
+	"go.minekube.com/gate/pkg/util/componentutil"
+	"go.minekube.com/gate/pkg/util/configutil"
+	"go.minekube.com/gate/pkg/util/favicon"
 	"go.minekube.com/gate/pkg/util/validation"
 )
 
@@ -18,7 +22,7 @@ var DefaultConfig = Config{
 	},
 	Status: Status{
 		ShowMaxPlayers: 1000,
-		Motd:           "§bA Gate Proxy\n§bVisit ➞ §fgit.luolix.top/minekube/gate",
+		Motd:           defaultMotd(),
 		// Contains Gate's icon
 		Favicon:         "data:image/png;base64,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",
 		LogPingRequests: false,
@@ -61,11 +65,18 @@ var DefaultConfig = Config{
 	RequireBuiltinCommandPermissions:    false,
 	AnnounceProxyCommands:               true,
 	Debug:                               false,
-	ShutdownReason:                      "§cGate proxy is shutting down...\nPlease reconnect in a moment!",
+	ShutdownReason:                      defaultShutdownReason(),
 	ForceKeyAuthentication:              true,
 	Lite:                                liteconfig.DefaultConfig,
 }
 
+func defaultMotd() *configutil.TextComponent {
+	return text("§bA Gate Proxy\n§bVisit ➞ §fgit.luolix.top/minekube/gate")
+}
+func defaultShutdownReason() *configutil.TextComponent {
+	return text("§cGate proxy is shutting down...\nPlease reconnect in a moment!")
+}
+
 // Config is the configuration of the proxy.
 type Config struct { // TODO use https://github.com/projectdiscovery/yamldoc-go for generating output yaml and markdown for the docs
 	Bind string `yaml:"bind"` // The address to listen for connections.
@@ -101,19 +112,19 @@ type Config struct { // TODO use https://github.com/projectdiscovery/yamldoc-go
 	AnnounceProxyCommands            bool `yaml:"announceProxyCommands"`
 	ForceKeyAuthentication           bool `yaml:"forceKeyAuthentication"` // Added in 1.19
 
-	Debug          bool   `yaml:"debug"`
-	ShutdownReason string `yaml:"shutdownReason"`
+	Debug          bool                      `yaml:"debug"`
+	ShutdownReason *configutil.TextComponent `yaml:"shutdownReason"`
 
 	Lite liteconfig.Config `yaml:"lite"`
 }
 
 type (
 	ForcedHosts map[string][]string // virtualhost:server names
 	Status      struct {
-		ShowMaxPlayers  int    `yaml:"showMaxPlayers"`
-		Motd            string `yaml:"motd"`
-		Favicon         string `yaml:"favicon"`
-		LogPingRequests bool   `yaml:"logPingRequests"`
+		ShowMaxPlayers  int                       `yaml:"showMaxPlayers"`
+		Motd            *configutil.TextComponent `yaml:"motd"`
+		Favicon         favicon.Favicon           `yaml:"favicon"`
+		LogPingRequests bool                      `yaml:"logPingRequests"`
 	}
 	Query struct {
 		Enabled     bool `yaml:"enabled"`
@@ -136,7 +147,7 @@ type (
 	}
 	QuotaSettings struct {
 		Enabled    bool    `yaml:"enabled"`    // If false, there is no such limiting.
-		OPS        float32 `yaml:"OPS"`        // Allowed operations/events per second, per IP block
+		OPS        float32 `yaml:"ops"`        // Allowed operations/events per second, per IP block
 		Burst      int     `yaml:"burst"`      // The maximum events per second, per block; the size of the token bucket
 		MaxEntries int     `yaml:"maxEntries"` // Maximum number of IP blocks to keep track of in cache
 	}
@@ -243,3 +254,15 @@ func (c *Config) Validate() (warns []error, errs []error) {
 
 	return
 }
+
+func text(s string) *configutil.TextComponent {
+	return (*configutil.TextComponent)(must(componentutil.ParseTextComponent(
+		version.MinimumVersion.Protocol, s)))
+}
+
+func must[T any](t T, err error) T {
+	if err != nil {
+		panic(err)
+	}
+	return t
+}

pkg/edition/java/config/config_test.go

@@ -0,0 +1,12 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_texts(t *testing.T) {
+	require.NotNil(t, defaultMotd())
+	require.NotNil(t, defaultShutdownReason())
+}