2024-04-17 20:20:44 +02:00

773 lines
22 KiB
Go

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
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("tuning.batch_change_delay", "800ms")
viper.SetDefault("tuning.node_mapsession_buffered_chan_size", 30)
viper.SetDefault("prefixes.allocation", string(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,
)
}
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",
),
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") != ""
}