ipn/ipnlocal, net/dns*, util/cloudenv: add AWS DNS support

And remove the GCP special-casing from ipn/ipnlocal; do it only in the
forwarder for *.internal.

Fixes #4980
Fixes #4981

Change-Id: I5c481e96d91f3d51d274a80fbd37c38f16dfa5cb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
2022-06-29 19:32:41 -07:00
committed by Brad Fitzpatrick
parent 88c2afd1e3
commit aa37aece9c
7 changed files with 103 additions and 82 deletions

View File

@@ -306,42 +306,6 @@ func TestDNSConfigForNetmap(t *testing.T) {
Routes: map[dnsname.FQDN][]*dnstype.Resolver{},
},
},
{
name: "google_cloud",
nm: &netmap.NetworkMap{
DNS: tailcfg.DNSConfig{},
},
cloud: cloudenv.GCP,
prefs: &ipn.Prefs{
CorpDNS: true,
},
want: &dns.Config{
Hosts: map[dnsname.FQDN][]netaddr.IP{},
Routes: map[dnsname.FQDN][]*dnstype.Resolver{
"internal.": []*dnstype.Resolver{{Addr: cloudenv.GoogleMetadataAndDNSIP}},
},
},
},
{
name: "google_cloud_with_exiting_internal",
nm: &netmap.NetworkMap{
DNS: tailcfg.DNSConfig{
Routes: map[string][]*dnstype.Resolver{
".internal": []*dnstype.Resolver{{Addr: "1.2.3.4"}},
},
},
},
cloud: cloudenv.GCP,
prefs: &ipn.Prefs{
CorpDNS: true,
},
want: &dns.Config{
Hosts: map[dnsname.FQDN][]netaddr.IP{},
Routes: map[dnsname.FQDN][]*dnstype.Resolver{
"internal.": []*dnstype.Resolver{{Addr: "1.2.3.4"}},
},
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
@@ -350,7 +314,7 @@ func TestDNSConfigForNetmap(t *testing.T) {
verOS = "linux"
}
var log tstest.MemLogger
got := dnsConfigForNetmap(tt.nm, tt.prefs, log.Logf, verOS, tt.cloud)
got := dnsConfigForNetmap(tt.nm, tt.prefs, log.Logf, verOS)
if !reflect.DeepEqual(got, tt.want) {
gotj, _ := json.MarshalIndent(got, "", "\t")
wantj, _ := json.MarshalIndent(tt.want, "", "\t")

View File

@@ -48,7 +48,6 @@ import (
"tailscale.com/types/persist"
"tailscale.com/types/preftype"
"tailscale.com/types/views"
"tailscale.com/util/cloudenv"
"tailscale.com/util/deephash"
"tailscale.com/util/dnsname"
"tailscale.com/util/multierr"
@@ -2222,7 +2221,7 @@ func (b *LocalBackend) authReconfig() {
}
rcfg := b.routerConfig(cfg, prefs, oneCGNATRoute)
dcfg := dnsConfigForNetmap(nm, prefs, b.logf, version.OS(), cloudenv.Get())
dcfg := dnsConfigForNetmap(nm, prefs, b.logf, version.OS())
err = b.e.Reconfig(cfg, rcfg, dcfg, nm.Debug)
if err == wgengine.ErrNoChanges {
@@ -2238,7 +2237,7 @@ func (b *LocalBackend) authReconfig() {
//
// The versionOS is a Tailscale-style version ("iOS", "macOS") and not
// a runtime.GOOS.
func dnsConfigForNetmap(nm *netmap.NetworkMap, prefs *ipn.Prefs, logf logger.Logf, versionOS string, cloud cloudenv.Cloud) *dns.Config {
func dnsConfigForNetmap(nm *netmap.NetworkMap, prefs *ipn.Prefs, logf logger.Logf, versionOS string) *dns.Config {
dcfg := &dns.Config{
Routes: map[dnsname.FQDN][]*dnstype.Resolver{},
Hosts: map[dnsname.FQDN][]netaddr.IP{},
@@ -2327,18 +2326,6 @@ func dnsConfigForNetmap(nm *netmap.NetworkMap, prefs *ipn.Prefs, logf logger.Log
}
}
// If we're running on Google Cloud Platform, add a DNS route for its
// *.internal DNS names to its metadata DNS IP, unless the tailnet already
// defines one. This is especially important on their standard VM images
// that don't included systemd-resolved, so we were effectively breaking
// their *.internal DNS names previously when the tailnet had explicit DNS
// servers set ("override local DNS" checked).
if cloud == cloudenv.GCP {
if _, ok := dcfg.Routes["internal."]; !ok {
dcfg.Routes["internal."] = []*dnstype.Resolver{{Addr: cloudenv.GoogleMetadataAndDNSIP}}
}
}
addDefault := func(resolvers []*dnstype.Resolver) {
for _, r := range resolvers {
dcfg.DefaultResolvers = append(dcfg.DefaultResolvers, r)