add bindAddress configuration option (#320)

* add bindAddress configuration option

* clarify that bindAddress can be a hostname

cmd/gotosocial/generalflags.go

@@ -62,6 +62,12 @@ func generalFlags(flagNames, envNames config.Flags, defaults config.Defaults) []
 			Value:   defaults.Protocol,
 			EnvVars: []string{envNames.Protocol},
 		},
+		&cli.StringFlag{
+			Name:    flagNames.BindAddress,
+			Usage:   "Bind address to use for the GoToSocial server (eg., 0.0.0.0, 172.138.0.9, [::], localhost). For ipv6, enclose the address in square brackets, eg [2a02:1807:1430:500:13f5:5efb:3f3a:1191]. Default binds to all interfaces.",
+			Value:   defaults.BindAddress,
+			EnvVars: []string{envNames.BindAddress},
+		},
 		&cli.IntFlag{
 			Name:    flagNames.Port,
 			Usage:   "Port to use for GoToSocial. Change this to 443 if you're running the binary directly on the host machine.",

docs/configuration/general.md

@@ -1,6 +1,6 @@
 # General
 
-The top-level configuration for GoToSocial, including basic things like host and transport protocol.
+The top-level configuration for GoToSocial, including basic things like host, port, bind address and transport protocol.
 
 The only things you *really* need to set here are `host`, which should be the hostname where your instance is reachable, and probably `port`.
 
@@ -48,6 +48,15 @@ accountDomain: ""
 # Default: "https"
 protocol: "https"
 
+# String. Address to bind the GoToSocial server to.
+# This can be an IPv4 address or an IPv6 address (surrounded in square brackets), or a hostname.
+# Default value will bind to all interfaces.
+# You probably won't need to change this unless you're setting GoToSocial up in some fancy way or
+# you have specific networking requirements.
+# Examples: ["0.0.0.0", "172.128.0.16", "localhost", "[::]", "[2a02:1807:1430:500:13f5:5efb:3f3a:1191]"]
+# Default: "0.0.0.0"
+bindAddress: "0.0.0.0"
+
 # Int. Listen port for the GoToSocial webserver + API. If you're running behind a reverse proxy and/or in a docker,
 # container, just set this to whatever you like (or leave the default), and make sure it's forwarded properly.
 # If you are running with built-in letsencrypt enabled, and running GoToSocial directly on a host machine, you will

example/config.yaml

@@ -55,6 +55,15 @@ accountDomain: ""
 # Default: "https"
 protocol: "https"
 
+# String. Address to bind the GoToSocial server to.
+# This can be an IPv4 address or an IPv6 address (surrounded in square brackets), or a hostname.
+# Default value will bind to all interfaces.
+# You probably won't need to change this unless you're setting GoToSocial up in some fancy way or
+# you have specific networking requirements.
+# Examples: ["0.0.0.0", "172.128.0.16", "localhost", "[::]", "[2a02:1807:1430:500:13f5:5efb:3f3a:1191]"]
+# Default: "0.0.0.0"
+bindAddress: "0.0.0.0"
+
 # Int. Listen port for the GoToSocial webserver + API. If you're running behind a reverse proxy and/or in a docker,
 # container, just set this to whatever you like (or leave the default), and make sure it's forwarded properly.
 # If you are running with built-in letsencrypt enabled, and running GoToSocial directly on a host machine, you will

internal/config/config.go

@@ -53,6 +53,7 @@ type Config struct {
 	Host              string             `yaml:"host"`
 	AccountDomain     string             `yaml:"accountDomain"`
 	Protocol          string             `yaml:"protocol"`
+	BindAddress       string             `yaml:"bindAddress"`
 	Port              int                `yaml:"port"`
 	TrustedProxies    []string           `yaml:"trustedProxies"`
 	DBConfig          *DBConfig          `yaml:"db"`
@@ -159,6 +160,10 @@ func (c *Config) ParseCLIFlags(f KeyedFlags, version string) error {
 		return errors.New("protocol was not set")
 	}
 
+	if c.BindAddress == "" || f.IsSet(fn.BindAddress) {
+		c.BindAddress = f.String(fn.BindAddress)
+	}
+
 	if c.Port == 0 || f.IsSet(fn.Port) {
 		c.Port = f.Int(fn.Port)
 	}
@@ -374,6 +379,7 @@ type Flags struct {
 	Host            string
 	AccountDomain   string
 	Protocol        string
+	BindAddress     string
 	Port            string
 	TrustedProxies  string
 
@@ -438,6 +444,7 @@ type Defaults struct {
 	Host            string
 	AccountDomain   string
 	Protocol        string
+	BindAddress     string
 	Port            int
 	TrustedProxies  []string
 	SoftwareVersion string
@@ -505,6 +512,7 @@ func GetFlagNames() Flags {
 		Host:            "host",
 		AccountDomain:   "account-domain",
 		Protocol:        "protocol",
+		BindAddress:     "bind-address",
 		Port:            "port",
 		TrustedProxies:  "trusted-proxies",
 
@@ -572,6 +580,7 @@ func GetEnvNames() Flags {
 		Host:            "GTS_HOST",
 		AccountDomain:   "GTS_ACCOUNT_DOMAIN",
 		Protocol:        "GTS_PROTOCOL",
+		BindAddress:     "GTS_BIND_ADDRESS",
 		Port:            "GTS_PORT",
 		TrustedProxies:  "GTS_TRUSTED_PROXIES",
 

internal/config/default.go

@@ -11,6 +11,7 @@ func TestDefault() *Config {
 		Host:            defaults.Host,
 		AccountDomain:   defaults.AccountDomain,
 		Protocol:        defaults.Protocol,
+		BindAddress:     defaults.BindAddress,
 		Port:            defaults.Port,
 		TrustedProxies:  defaults.TrustedProxies,
 		SoftwareVersion: defaults.SoftwareVersion,
@@ -85,6 +86,7 @@ func Default() *Config {
 		ApplicationName: defaults.ApplicationName,
 		Host:            defaults.Host,
 		Protocol:        defaults.Protocol,
+		BindAddress:     defaults.BindAddress,
 		Port:            defaults.Port,
 		TrustedProxies:  defaults.TrustedProxies,
 		SoftwareVersion: defaults.SoftwareVersion,
@@ -161,6 +163,7 @@ func GetDefaults() Defaults {
 		Host:            "",
 		AccountDomain:   "",
 		Protocol:        "https",
+		BindAddress:     "0.0.0.0",
 		Port:            8080,
 		TrustedProxies:  []string{"127.0.0.1/32"}, // localhost
 
@@ -227,6 +230,7 @@ func GetTestDefaults() Defaults {
 		Host:            "localhost:8080",
 		AccountDomain:   "localhost:8080",
 		Protocol:        "http",
+		BindAddress:     "127.0.0.1",
 		Port:            8080,
 		TrustedProxies:  []string{"127.0.0.1/32"},
 

internal/router/router.go

@@ -72,7 +72,8 @@ func (r *router) Start() {
 	if r.config.LetsEncryptConfig.Enabled {
 		// serve the http handler on the selected letsencrypt port, for receiving letsencrypt requests and solving their devious riddles
 		go func() {
-			if err := http.ListenAndServe(fmt.Sprintf(":%d", r.config.LetsEncryptConfig.Port), r.certManager.HTTPHandler(http.HandlerFunc(httpsRedirect))); err != nil && err != http.ErrServerClosed {
+			listen := fmt.Sprintf("%s:%d", r.config.BindAddress, r.config.LetsEncryptConfig.Port)
+			if err := http.ListenAndServe(listen, r.certManager.HTTPHandler(http.HandlerFunc(httpsRedirect))); err != nil && err != http.ErrServerClosed {
 				logrus.Fatalf("listen: %s", err)
 			}
 		}()
@@ -138,8 +139,9 @@ func New(ctx context.Context, cfg *config.Config, db db.DB) (Router, error) {
 	}
 
 	// create the http server here, passing the gin engine as handler
+	listen := fmt.Sprintf("%s:%d", cfg.BindAddress, cfg.Port)
 	s := &http.Server{
-		Addr:              fmt.Sprintf(":%d", cfg.Port),
+		Addr:              listen,
 		Handler:           engine,
 		ReadTimeout:       readTimeout,
 		WriteTimeout:      writeTimeout,