package types import ( "errors" "fmt" "io/fs" "net/netip" "net/url" "os" "strings" "time" "github.com/coreos/go-oidc/v3/oidc" "github.com/juanfont/headscale/hscontrol/util" "github.com/prometheus/common/model" "github.com/rs/zerolog" "github.com/rs/zerolog/log" "github.com/spf13/viper" "go4.org/netipx" "tailscale.com/net/tsaddr" "tailscale.com/tailcfg" "tailscale.com/types/dnstype" ) const ( defaultOIDCExpiryTime = 180 * 24 * time.Hour // 180 Days maxDuration time.Duration = 1<<63 - 1 ) var errOidcMutuallyExclusive = errors.New( "oidc_client_secret and oidc_client_secret_path are mutually exclusive", ) type IPAllocationStrategy string const ( IPAllocationStrategySequential IPAllocationStrategy = "sequential" IPAllocationStrategyRandom IPAllocationStrategy = "random" ) // Config contains the initial Headscale configuration. type Config struct { ServerURL string Addr string MetricsAddr string GRPCAddr string GRPCAllowInsecure bool EphemeralNodeInactivityTimeout time.Duration NodeUpdateCheckInterval time.Duration PrefixV4 *netip.Prefix PrefixV6 *netip.Prefix IPAllocation IPAllocationStrategy NoisePrivateKeyPath string BaseDomain string Log LogConfig DisableUpdateCheck bool Database DatabaseConfig DERP DERPConfig TLS TLSConfig ACMEURL string ACMEEmail string DNSConfig *tailcfg.DNSConfig UnixSocket string UnixSocketPermission fs.FileMode OIDC OIDCConfig LogTail LogTailConfig RandomizeClientPort bool CLI CLIConfig ACL ACLConfig Tuning Tuning } type SqliteConfig struct { Path string } type PostgresConfig struct { Host string Port int Name string User string Pass string Ssl string MaxOpenConnections int MaxIdleConnections int ConnMaxIdleTimeSecs int } type DatabaseConfig struct { // Type sets the database type, either "sqlite3" or "postgres" Type string Debug bool Sqlite SqliteConfig Postgres PostgresConfig } type TLSConfig struct { CertPath string KeyPath string LetsEncrypt LetsEncryptConfig } type LetsEncryptConfig struct { Listen string Hostname string CacheDir string ChallengeType string } type OIDCConfig struct { OnlyStartIfOIDCIsAvailable bool Issuer string ClientID string ClientSecret string Scope []string ExtraParams map[string]string AllowedDomains []string AllowedUsers []string AllowedGroups []string StripEmaildomain bool Expiry time.Duration UseExpiryFromToken bool } type DERPConfig struct { ServerEnabled bool AutomaticallyAddEmbeddedDerpRegion bool ServerRegionID int ServerRegionCode string ServerRegionName string ServerPrivateKeyPath string STUNAddr string URLs []url.URL Paths []string AutoUpdate bool UpdateFrequency time.Duration IPv4 string IPv6 string } type LogTailConfig struct { Enabled bool } type CLIConfig struct { Address string APIKey string Timeout time.Duration Insecure bool } type ACLConfig struct { PolicyPath string } type LogConfig struct { Format string Level zerolog.Level } type Tuning struct { BatchChangeDelay time.Duration NodeMapSessionBufferedChanSize int } func LoadConfig(path string, isFile bool) error { if isFile { viper.SetConfigFile(path) } else { viper.SetConfigName("config") if path == "" { viper.AddConfigPath("/etc/headscale/") viper.AddConfigPath("$HOME/.headscale") viper.AddConfigPath(".") } else { // For testing viper.AddConfigPath(path) } } viper.SetEnvPrefix("headscale") viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_")) viper.AutomaticEnv() viper.SetDefault("tls_letsencrypt_cache_dir", "/var/www/.cache") viper.SetDefault("tls_letsencrypt_challenge_type", HTTP01ChallengeType) viper.SetDefault("log.level", "info") viper.SetDefault("log.format", TextLogFormat) viper.SetDefault("dns_config", nil) viper.SetDefault("dns_config.override_local_dns", true) viper.SetDefault("derp.server.enabled", false) viper.SetDefault("derp.server.stun.enabled", true) viper.SetDefault("derp.server.automatically_add_embedded_derp_region", true) viper.SetDefault("unix_socket", "/var/run/headscale/headscale.sock") viper.SetDefault("unix_socket_permission", "0o770") viper.SetDefault("grpc_listen_addr", ":50443") viper.SetDefault("grpc_allow_insecure", false) viper.SetDefault("cli.timeout", "5s") viper.SetDefault("cli.insecure", false) viper.SetDefault("database.postgres.ssl", false) viper.SetDefault("database.postgres.max_open_conns", 10) viper.SetDefault("database.postgres.max_idle_conns", 10) viper.SetDefault("database.postgres.conn_max_idle_time_secs", 3600) viper.SetDefault("oidc.scope", []string{oidc.ScopeOpenID, "profile", "email"}) viper.SetDefault("oidc.strip_email_domain", true) viper.SetDefault("oidc.only_start_if_oidc_is_available", true) viper.SetDefault("oidc.expiry", "180d") viper.SetDefault("oidc.use_expiry_from_token", false) viper.SetDefault("logtail.enabled", false) viper.SetDefault("randomize_client_port", false) viper.SetDefault("ephemeral_node_inactivity_timeout", "120s") viper.SetDefault("node_update_check_interval", "10s") viper.SetDefault("tuning.batch_change_delay", "800ms") viper.SetDefault("tuning.node_mapsession_buffered_chan_size", 30) viper.SetDefault("prefixes.allocation", IPAllocationStrategySequential) if IsCLIConfigured() { return nil } if err := viper.ReadInConfig(); err != nil { log.Warn().Err(err).Msg("Failed to read configuration from disk") return fmt.Errorf("fatal error reading config file: %w", err) } // Collect any validation errors and return them all at once var errorText string if (viper.GetString("tls_letsencrypt_hostname") != "") && ((viper.GetString("tls_cert_path") != "") || (viper.GetString("tls_key_path") != "")) { errorText += "Fatal config error: set either tls_letsencrypt_hostname or tls_cert_path/tls_key_path, not both\n" } if !viper.IsSet("noise") || viper.GetString("noise.private_key_path") == "" { errorText += "Fatal config error: headscale now requires a new `noise.private_key_path` field in the config file for the Tailscale v2 protocol\n" } if (viper.GetString("tls_letsencrypt_hostname") != "") && (viper.GetString("tls_letsencrypt_challenge_type") == TLSALPN01ChallengeType) && (!strings.HasSuffix(viper.GetString("listen_addr"), ":443")) { // this is only a warning because there could be something sitting in front of headscale that redirects the traffic (e.g. an iptables rule) log.Warn(). Msg("Warning: when using tls_letsencrypt_hostname with TLS-ALPN-01 as challenge type, headscale must be reachable on port 443, i.e. listen_addr should probably end in :443") } if (viper.GetString("tls_letsencrypt_challenge_type") != HTTP01ChallengeType) && (viper.GetString("tls_letsencrypt_challenge_type") != TLSALPN01ChallengeType) { errorText += "Fatal config error: the only supported values for tls_letsencrypt_challenge_type are HTTP-01 and TLS-ALPN-01\n" } if !strings.HasPrefix(viper.GetString("server_url"), "http://") && !strings.HasPrefix(viper.GetString("server_url"), "https://") { errorText += "Fatal config error: server_url must start with https:// or http://\n" } // Minimum inactivity time out is keepalive timeout (60s) plus a few seconds // to avoid races minInactivityTimeout, _ := time.ParseDuration("65s") if viper.GetDuration("ephemeral_node_inactivity_timeout") <= minInactivityTimeout { errorText += fmt.Sprintf( "Fatal config error: ephemeral_node_inactivity_timeout (%s) is set too low, must be more than %s", viper.GetString("ephemeral_node_inactivity_timeout"), minInactivityTimeout, ) } maxNodeUpdateCheckInterval, _ := time.ParseDuration("60s") if viper.GetDuration("node_update_check_interval") > maxNodeUpdateCheckInterval { errorText += fmt.Sprintf( "Fatal config error: node_update_check_interval (%s) is set too high, must be less than %s", viper.GetString("node_update_check_interval"), maxNodeUpdateCheckInterval, ) } if errorText != "" { // nolint return errors.New(strings.TrimSuffix(errorText, "\n")) } else { return nil } } func GetTLSConfig() TLSConfig { return TLSConfig{ LetsEncrypt: LetsEncryptConfig{ Hostname: viper.GetString("tls_letsencrypt_hostname"), Listen: viper.GetString("tls_letsencrypt_listen"), CacheDir: util.AbsolutePathFromConfigPath( viper.GetString("tls_letsencrypt_cache_dir"), ), ChallengeType: viper.GetString("tls_letsencrypt_challenge_type"), }, CertPath: util.AbsolutePathFromConfigPath( viper.GetString("tls_cert_path"), ), KeyPath: util.AbsolutePathFromConfigPath( viper.GetString("tls_key_path"), ), } } func GetDERPConfig() DERPConfig { serverEnabled := viper.GetBool("derp.server.enabled") serverRegionID := viper.GetInt("derp.server.region_id") serverRegionCode := viper.GetString("derp.server.region_code") serverRegionName := viper.GetString("derp.server.region_name") stunAddr := viper.GetString("derp.server.stun_listen_addr") privateKeyPath := util.AbsolutePathFromConfigPath( viper.GetString("derp.server.private_key_path"), ) ipv4 := viper.GetString("derp.server.ipv4") ipv6 := viper.GetString("derp.server.ipv6") automaticallyAddEmbeddedDerpRegion := viper.GetBool( "derp.server.automatically_add_embedded_derp_region", ) if serverEnabled && stunAddr == "" { log.Fatal(). Msg("derp.server.stun_listen_addr must be set if derp.server.enabled is true") } urlStrs := viper.GetStringSlice("derp.urls") urls := make([]url.URL, len(urlStrs)) for index, urlStr := range urlStrs { urlAddr, err := url.Parse(urlStr) if err != nil { log.Error(). Str("url", urlStr). Err(err). Msg("Failed to parse url, ignoring...") } urls[index] = *urlAddr } paths := viper.GetStringSlice("derp.paths") if serverEnabled && !automaticallyAddEmbeddedDerpRegion && len(paths) == 0 { log.Fatal(). Msg("Disabling derp.server.automatically_add_embedded_derp_region requires to configure the derp server in derp.paths") } autoUpdate := viper.GetBool("derp.auto_update_enabled") updateFrequency := viper.GetDuration("derp.update_frequency") return DERPConfig{ ServerEnabled: serverEnabled, ServerRegionID: serverRegionID, ServerRegionCode: serverRegionCode, ServerRegionName: serverRegionName, ServerPrivateKeyPath: privateKeyPath, STUNAddr: stunAddr, URLs: urls, Paths: paths, AutoUpdate: autoUpdate, UpdateFrequency: updateFrequency, IPv4: ipv4, IPv6: ipv6, AutomaticallyAddEmbeddedDerpRegion: automaticallyAddEmbeddedDerpRegion, } } func GetLogTailConfig() LogTailConfig { enabled := viper.GetBool("logtail.enabled") return LogTailConfig{ Enabled: enabled, } } func GetACLConfig() ACLConfig { policyPath := viper.GetString("acl_policy_path") return ACLConfig{ PolicyPath: policyPath, } } func GetLogConfig() LogConfig { logLevelStr := viper.GetString("log.level") logLevel, err := zerolog.ParseLevel(logLevelStr) if err != nil { logLevel = zerolog.DebugLevel } logFormatOpt := viper.GetString("log.format") var logFormat string switch logFormatOpt { case "json": logFormat = JSONLogFormat case "text": logFormat = TextLogFormat case "": logFormat = TextLogFormat default: log.Error(). Str("func", "GetLogConfig"). Msgf("Could not parse log format: %s. Valid choices are 'json' or 'text'", logFormatOpt) } return LogConfig{ Format: logFormat, Level: logLevel, } } func GetDatabaseConfig() DatabaseConfig { debug := viper.GetBool("database.debug") type_ := viper.GetString("database.type") switch type_ { case DatabaseSqlite, DatabasePostgres: break case "sqlite": type_ = "sqlite3" default: log.Fatal(). Msgf("invalid database type %q, must be sqlite, sqlite3 or postgres", type_) } return DatabaseConfig{ Type: type_, Debug: debug, Sqlite: SqliteConfig{ Path: util.AbsolutePathFromConfigPath( viper.GetString("database.sqlite.path"), ), }, Postgres: PostgresConfig{ Host: viper.GetString("database.postgres.host"), Port: viper.GetInt("database.postgres.port"), Name: viper.GetString("database.postgres.name"), User: viper.GetString("database.postgres.user"), Pass: viper.GetString("database.postgres.pass"), Ssl: viper.GetString("database.postgres.ssl"), MaxOpenConnections: viper.GetInt("database.postgres.max_open_conns"), MaxIdleConnections: viper.GetInt("database.postgres.max_idle_conns"), ConnMaxIdleTimeSecs: viper.GetInt( "database.postgres.conn_max_idle_time_secs", ), }, } } func GetDNSConfig() (*tailcfg.DNSConfig, string) { if viper.IsSet("dns_config") { dnsConfig := &tailcfg.DNSConfig{} overrideLocalDNS := viper.GetBool("dns_config.override_local_dns") if viper.IsSet("dns_config.nameservers") { nameserversStr := viper.GetStringSlice("dns_config.nameservers") nameservers := []netip.Addr{} resolvers := []*dnstype.Resolver{} for _, nameserverStr := range nameserversStr { // Search for explicit DNS-over-HTTPS resolvers if strings.HasPrefix(nameserverStr, "https://") { resolvers = append(resolvers, &dnstype.Resolver{ Addr: nameserverStr, }) // This nameserver can not be parsed as an IP address continue } // Parse nameserver as a regular IP nameserver, err := netip.ParseAddr(nameserverStr) if err != nil { log.Error(). Str("func", "getDNSConfig"). Err(err). Msgf("Could not parse nameserver IP: %s", nameserverStr) } nameservers = append(nameservers, nameserver) resolvers = append(resolvers, &dnstype.Resolver{ Addr: nameserver.String(), }) } dnsConfig.Nameservers = nameservers if overrideLocalDNS { dnsConfig.Resolvers = resolvers } else { dnsConfig.FallbackResolvers = resolvers } } if viper.IsSet("dns_config.restricted_nameservers") { dnsConfig.Routes = make(map[string][]*dnstype.Resolver) domains := []string{} restrictedDNS := viper.GetStringMapStringSlice( "dns_config.restricted_nameservers", ) for domain, restrictedNameservers := range restrictedDNS { restrictedResolvers := make( []*dnstype.Resolver, len(restrictedNameservers), ) for index, nameserverStr := range restrictedNameservers { nameserver, err := netip.ParseAddr(nameserverStr) if err != nil { log.Error(). Str("func", "getDNSConfig"). Err(err). Msgf("Could not parse restricted nameserver IP: %s", nameserverStr) } restrictedResolvers[index] = &dnstype.Resolver{ Addr: nameserver.String(), } } dnsConfig.Routes[domain] = restrictedResolvers domains = append(domains, domain) } dnsConfig.Domains = domains } if viper.IsSet("dns_config.domains") { domains := viper.GetStringSlice("dns_config.domains") if len(dnsConfig.Resolvers) > 0 { dnsConfig.Domains = domains } else if domains != nil { log.Warn(). Msg("Warning: dns_config.domains is set, but no nameservers are configured. Ignoring domains.") } } if viper.IsSet("dns_config.extra_records") { var extraRecords []tailcfg.DNSRecord err := viper.UnmarshalKey("dns_config.extra_records", &extraRecords) if err != nil { log.Error(). Str("func", "getDNSConfig"). Err(err). Msgf("Could not parse dns_config.extra_records") } dnsConfig.ExtraRecords = extraRecords } if viper.IsSet("dns_config.magic_dns") { dnsConfig.Proxied = viper.GetBool("dns_config.magic_dns") } var baseDomain string if viper.IsSet("dns_config.base_domain") { baseDomain = viper.GetString("dns_config.base_domain") } else { baseDomain = "headscale.net" // does not really matter when MagicDNS is not enabled } log.Trace().Interface("dns_config", dnsConfig).Msg("DNS configuration loaded") return dnsConfig, baseDomain } return nil, "" } func PrefixV4() (*netip.Prefix, error) { prefixV4Str := viper.GetString("prefixes.v4") if prefixV4Str == "" { return nil, nil } prefixV4, err := netip.ParsePrefix(prefixV4Str) if err != nil { return nil, fmt.Errorf("parsing IPv4 prefix from config: %w", err) } builder := netipx.IPSetBuilder{} builder.AddPrefix(tsaddr.CGNATRange()) builder.AddPrefix(tsaddr.TailscaleULARange()) ipSet, _ := builder.IPSet() if !ipSet.ContainsPrefix(prefixV4) { log.Warn(). Msgf("Prefix %s is not in the %s range. This is an unsupported configuration.", prefixV4Str, tsaddr.CGNATRange()) } return &prefixV4, nil } func PrefixV6() (*netip.Prefix, error) { prefixV6Str := viper.GetString("prefixes.v6") if prefixV6Str == "" { return nil, nil } prefixV6, err := netip.ParsePrefix(prefixV6Str) if err != nil { return nil, fmt.Errorf("parsing IPv6 prefix from config: %w", err) } builder := netipx.IPSetBuilder{} builder.AddPrefix(tsaddr.CGNATRange()) builder.AddPrefix(tsaddr.TailscaleULARange()) ipSet, _ := builder.IPSet() if !ipSet.ContainsPrefix(prefixV6) { log.Warn(). Msgf("Prefix %s is not in the %s range. This is an unsupported configuration.", prefixV6Str, tsaddr.TailscaleULARange()) } return &prefixV6, nil } func GetHeadscaleConfig() (*Config, error) { if IsCLIConfigured() { return &Config{ CLI: CLIConfig{ Address: viper.GetString("cli.address"), APIKey: viper.GetString("cli.api_key"), Timeout: viper.GetDuration("cli.timeout"), Insecure: viper.GetBool("cli.insecure"), }, }, nil } prefix4, err := PrefixV4() if err != nil { return nil, err } prefix6, err := PrefixV6() if err != nil { return nil, err } allocStr := viper.GetString("prefixes.allocation") var alloc IPAllocationStrategy switch allocStr { case string(IPAllocationStrategySequential): alloc = IPAllocationStrategySequential case string(IPAllocationStrategyRandom): alloc = IPAllocationStrategyRandom default: log.Fatal().Msgf("config error, prefixes.allocation is set to %s, which is not a valid strategy, allowed options: %s, %s", allocStr, IPAllocationStrategySequential, IPAllocationStrategyRandom) } dnsConfig, baseDomain := GetDNSConfig() derpConfig := GetDERPConfig() logConfig := GetLogTailConfig() randomizeClientPort := viper.GetBool("randomize_client_port") oidcClientSecret := viper.GetString("oidc.client_secret") oidcClientSecretPath := viper.GetString("oidc.client_secret_path") if oidcClientSecretPath != "" && oidcClientSecret != "" { return nil, errOidcMutuallyExclusive } if oidcClientSecretPath != "" { secretBytes, err := os.ReadFile(os.ExpandEnv(oidcClientSecretPath)) if err != nil { return nil, err } oidcClientSecret = strings.TrimSpace(string(secretBytes)) } return &Config{ ServerURL: viper.GetString("server_url"), Addr: viper.GetString("listen_addr"), MetricsAddr: viper.GetString("metrics_listen_addr"), GRPCAddr: viper.GetString("grpc_listen_addr"), GRPCAllowInsecure: viper.GetBool("grpc_allow_insecure"), DisableUpdateCheck: viper.GetBool("disable_check_updates"), PrefixV4: prefix4, PrefixV6: prefix6, IPAllocation: IPAllocationStrategy(alloc), NoisePrivateKeyPath: util.AbsolutePathFromConfigPath( viper.GetString("noise.private_key_path"), ), BaseDomain: baseDomain, DERP: derpConfig, EphemeralNodeInactivityTimeout: viper.GetDuration( "ephemeral_node_inactivity_timeout", ), NodeUpdateCheckInterval: viper.GetDuration( "node_update_check_interval", ), Database: GetDatabaseConfig(), TLS: GetTLSConfig(), DNSConfig: dnsConfig, ACMEEmail: viper.GetString("acme_email"), ACMEURL: viper.GetString("acme_url"), UnixSocket: viper.GetString("unix_socket"), UnixSocketPermission: util.GetFileMode("unix_socket_permission"), OIDC: OIDCConfig{ OnlyStartIfOIDCIsAvailable: viper.GetBool( "oidc.only_start_if_oidc_is_available", ), Issuer: viper.GetString("oidc.issuer"), ClientID: viper.GetString("oidc.client_id"), ClientSecret: oidcClientSecret, Scope: viper.GetStringSlice("oidc.scope"), ExtraParams: viper.GetStringMapString("oidc.extra_params"), AllowedDomains: viper.GetStringSlice("oidc.allowed_domains"), AllowedUsers: viper.GetStringSlice("oidc.allowed_users"), AllowedGroups: viper.GetStringSlice("oidc.allowed_groups"), StripEmaildomain: viper.GetBool("oidc.strip_email_domain"), Expiry: func() time.Duration { // if set to 0, we assume no expiry if value := viper.GetString("oidc.expiry"); value == "0" { return maxDuration } else { expiry, err := model.ParseDuration(value) if err != nil { log.Warn().Msg("failed to parse oidc.expiry, defaulting back to 180 days") return defaultOIDCExpiryTime } return time.Duration(expiry) } }(), UseExpiryFromToken: viper.GetBool("oidc.use_expiry_from_token"), }, LogTail: logConfig, RandomizeClientPort: randomizeClientPort, ACL: GetACLConfig(), CLI: CLIConfig{ Address: viper.GetString("cli.address"), APIKey: viper.GetString("cli.api_key"), Timeout: viper.GetDuration("cli.timeout"), Insecure: viper.GetBool("cli.insecure"), }, Log: GetLogConfig(), // TODO(kradalby): Document these settings when more stable Tuning: Tuning{ BatchChangeDelay: viper.GetDuration("tuning.batch_change_delay"), NodeMapSessionBufferedChanSize: viper.GetInt("tuning.node_mapsession_buffered_chan_size"), }, }, nil } func IsCLIConfigured() bool { return viper.GetString("cli.address") != "" && viper.GetString("cli.api_key") != "" }