Add support for Split DNS (implements #179)

This commit is contained in:
Juan Font Alonso 2021-10-19 20:51:43 +02:00
parent 9e1253ada1
commit 18b00b5d8d
3 changed files with 51 additions and 16 deletions

4
app.go
View file

@ -113,7 +113,9 @@ func NewHeadscale(cfg Config) (*Headscale, error) {
if err != nil { if err != nil {
return nil, err return nil, err
} }
h.cfg.DNSConfig.Routes = make(map[string][]dnstype.Resolver) if h.cfg.DNSConfig.Routes == nil { // we might have routes already from Split DNS
h.cfg.DNSConfig.Routes = make(map[string][]dnstype.Resolver)
}
for _, d := range magicDNSDomains { for _, d := range magicDNSDomains {
h.cfg.DNSConfig.Routes[d.WithoutTrailingDot()] = nil h.cfg.DNSConfig.Routes[d.WithoutTrailingDot()] = nil
} }

View file

@ -104,6 +104,33 @@ func GetDNSConfig() (*tailcfg.DNSConfig, string) {
dnsConfig.Nameservers = nameservers dnsConfig.Nameservers = nameservers
dnsConfig.Resolvers = resolvers dnsConfig.Resolvers = resolvers
} }
if viper.IsSet("dns_config.restricted_nameservers") {
if len(dnsConfig.Nameservers) > 0 {
dnsConfig.Routes = make(map[string][]dnstype.Resolver)
restrictedDNS := viper.GetStringMapStringSlice("dns_config.restricted_nameservers")
for domain, resNameservers := range restrictedDNS {
resResolvers := make([]dnstype.Resolver, len(resNameservers))
for index, nameserverStr := range resNameservers {
nameserver, err := netaddr.ParseIP(nameserverStr)
if err != nil {
log.Error().
Str("func", "getDNSConfig").
Err(err).
Msgf("Could not parse restricted nameserver IP: %s", nameserverStr)
}
resResolvers[index] = dnstype.Resolver{
Addr: nameserver.String(),
}
}
dnsConfig.Routes[domain] = resResolvers
}
} else {
log.Warn().
Msg("Warning: dns_config.restricted_nameservers is set, but no nameservers are configured. Ignoring restricted_nameservers.")
}
}
if viper.IsSet("dns_config.domains") { if viper.IsSet("dns_config.domains") {
dnsConfig.Domains = viper.GetStringSlice("dns_config.domains") dnsConfig.Domains = viper.GetStringSlice("dns_config.domains")
} }

View file

@ -11,23 +11,29 @@ Long story short, you can define the DNS servers you want to use in your tailnet
## Configuration reference ## Configuration reference
The setup is done via the `config.json` file, under the `dns_config` key. The setup is done via the `config.yaml` file, under the `dns_config` key.
```json ```yaml
{ server_url: http://127.0.0.1:8001
"server_url": "http://127.0.0.1:8001", listen_addr: 0.0.0.0:8001
"listen_addr": "0.0.0.0:8001", private_key_path: private.key
"private_key_path": "private.key", dns_config:
//... nameservers:
"dns_config": { - 1.1.1.1
"nameservers": ["1.1.1.1", "8.8.8.8"], - 8.8.8.8
"domains": [], restricted_nameservers:
"magic_dns": true, foo.bar.com:
"base_domain": "example.com" - 1.1.1.1
} darp.headscale.net:
} - 1.1.1.1
- 8.8.8.8
domains: []
magic_dns: true
base_domain: example.com
``` ```
- `nameservers`: The list of DNS servers to use. - `nameservers`: The list of DNS servers to use.
- `domains`: Search domains to inject. - `domains`: Search domains to inject.
- `magic_dns`: Whether to use [MagicDNS](https://tailscale.com/kb/1081/magicdns/). Only works if there is at least a nameserver defined. - `magic_dns`: Whether to use [MagicDNS](https://tailscale.com/kb/1081/magicdns/). Only works if there is at least a nameserver defined.
- `base_domain`: Defines the base domain to create the hostnames for MagicDNS. `base_domain` must be a FQDNs, without the trailing dot. The FQDN of the hosts will be `hostname.namespace.base_domain` (e.g., _myhost.mynamespace.example.com_). - `base_domain`: Defines the base domain to create the hostnames for MagicDNS. `base_domain` must be a FQDNs, without the trailing dot. The FQDN of the hosts will be `hostname.namespace.base_domain` (e.g., _myhost.mynamespace.example.com_).
- `restricted_nameservers`: Also known as Split DNS (see https://tailscale.com/kb/1054/dns/), list of search domains and the DNS you want to use for them.