Skip to content

Commit 2086714

Browse files
kylecarbskylecarbs
committed
feat: Add local configuration option for DERP mapping
This allows entirely airgapped geodistributed deployments of Coder!
1 parent f5bbbdf commit 2086714

File tree

3 files changed

+42
-5
lines changed

3 files changed

+42
-5
lines changed

‎cli/server.go

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -81,6 +81,7 @@ func Server(newAPI func(*coderd.Options) *coderd.API) *cobra.Command {
8181
derpServerRegionName string
8282
derpServerSTUNAddrs []string
8383
derpConfigURL string
84+
derpConfigPath string
8485
promEnabled bool
8586
promAddress string
8687
pprofEnabled bool
@@ -345,7 +346,7 @@ func Server(newAPI func(*coderd.Options) *coderd.API) *cobra.Command {
345346
if !derpServerEnabled {
346347
defaultRegion = nil
347348
}
348-
derpMap, err := tailnet.NewDERPMap(ctx, defaultRegion, derpServerSTUNAddrs, derpConfigURL)
349+
derpMap, err := tailnet.NewDERPMap(ctx, defaultRegion, derpServerSTUNAddrs, derpConfigURL, derpConfigPath)
349350
if err != nil {
350351
return xerrors.Errorf("create derp map: %w", err)
351352
}
@@ -753,6 +754,8 @@ func Server(newAPI func(*coderd.Options) *coderd.API) *cobra.Command {
753754
cliflag.StringVarP(root.Flags(), &address, "address", "a", "CODER_ADDRESS", "127.0.0.1:3000", "The address to serve the API and dashboard.")
754755
cliflag.StringVarP(root.Flags(), &derpConfigURL, "derp-config-url", "", "CODER_DERP_CONFIG_URL", "",
755756
"Specifies a URL to periodically fetch a DERP map. See: https://tailscale.com/kb/1118/custom-derp-servers/")
757+
cliflag.StringVarP(root.Flags(), &derpConfigPath, "derp-config-path", "", "CODER_DERP_CONFIG_PATH", "",
758+
"Specifies a path to read a DERP map from. See: https://tailscale.com/kb/1118/custom-derp-servers/")
756759
cliflag.BoolVarP(root.Flags(), &derpServerEnabled, "derp-server-enable", "", "CODER_DERP_SERVER_ENABLE", true, "Specifies whether to enable or disable the embedded DERP server.")
757760
cliflag.IntVarP(root.Flags(), &derpServerRegionID, "derp-server-region-id", "", "CODER_DERP_SERVER_REGION_ID", 999, "Specifies the region ID to use for the embedded DERP server.")
758761
cliflag.StringVarP(root.Flags(), &derpServerRegionCode, "derp-server-region-code", "", "CODER_DERP_SERVER_REGION_CODE", "coder", "Specifies the region code that is displayed in the Coder UI for the embedded DERP server.")
@@ -763,6 +766,7 @@ func Server(newAPI func(*coderd.Options) *coderd.API) *cobra.Command {
763766

764767
// Mark hidden while this feature is in testing!
765768
_ = root.Flags().MarkHidden("derp-config-url")
769+
_ = root.Flags().MarkHidden("derp-config-path")
766770
_ = root.Flags().MarkHidden("derp-server-enable")
767771
_ = root.Flags().MarkHidden("derp-server-region-id")
768772
_ = root.Flags().MarkHidden("derp-server-region-code")

‎tailnet/derpmap.go

Lines changed: 15 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -6,6 +6,7 @@ import (
66
"fmt"
77
"net"
88
"net/http"
9+
"os"
910
"strconv"
1011

1112
"golang.org/x/xerrors"
@@ -14,7 +15,10 @@ import (
1415

1516
// NewDERPMap constructs a DERPMap from a set of STUN addresses and optionally a remote
1617
// URL to fetch a mapping from e.g. https://controlplane.tailscale.com/derpmap/default.
17-
func NewDERPMap(ctx context.Context, region *tailcfg.DERPRegion, stunAddrs []string, remoteURL string) (*tailcfg.DERPMap, error) {
18+
func NewDERPMap(ctx context.Context, region *tailcfg.DERPRegion, stunAddrs []string, remoteURL, localPath string) (*tailcfg.DERPMap, error) {
19+
if remoteURL != "" && localPath != "" {
20+
return nil, xerrors.New("a remote URL or local path must be specified, not both")
21+
}
1822
if region != nil {
1923
for index, stunAddr := range stunAddrs {
2024
host, rawPort, err := net.SplitHostPort(stunAddr)
@@ -53,6 +57,16 @@ func NewDERPMap(ctx context.Context, region *tailcfg.DERPRegion, stunAddrs []str
5357
return nil, xerrors.Errorf("fetch derpmap: %w", err)
5458
}
5559
}
60+
if localPath != "" {
61+
content, err := os.ReadFile(localPath)
62+
if err != nil {
63+
return nil, xerrors.Errorf("read derpmap from %q: %w", localPath, err)
64+
}
65+
err = json.Unmarshal(content, &derpMap)
66+
if err != nil {
67+
return nil, xerrors.Errorf("unmarshal derpmap: %w", err)
68+
}
69+
}
5670
if region != nil {
5771
_, conflicts := derpMap.Regions[region.RegionID]
5872
if conflicts {

‎tailnet/derpmap_test.go

Lines changed: 22 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -5,6 +5,8 @@ import (
55
"encoding/json"
66
"net/http"
77
"net/http/httptest"
8+
"os"
9+
"path/filepath"
810
"testing"
911

1012
"github.com/stretchr/testify/require"
@@ -20,7 +22,7 @@ func TestNewDERPMap(t *testing.T) {
2022
derpMap, err := tailnet.NewDERPMap(context.Background(), &tailcfg.DERPRegion{
2123
RegionID: 1,
2224
Nodes: []*tailcfg.DERPNode{{}},
23-
}, []string{"stun.google.com:2345"}, "")
25+
}, []string{"stun.google.com:2345"}, "", "")
2426
require.NoError(t, err)
2527
require.Len(t, derpMap.Regions[1].Nodes, 2)
2628
})
@@ -37,7 +39,7 @@ func TestNewDERPMap(t *testing.T) {
3739
t.Cleanup(server.Close)
3840
derpMap, err := tailnet.NewDERPMap(context.Background(), &tailcfg.DERPRegion{
3941
RegionID: 2,
40-
}, []string{}, server.URL)
42+
}, []string{}, server.URL, "")
4143
require.NoError(t, err)
4244
require.Len(t, derpMap.Regions, 2)
4345
})
@@ -54,7 +56,24 @@ func TestNewDERPMap(t *testing.T) {
5456
t.Cleanup(server.Close)
5557
_, err := tailnet.NewDERPMap(context.Background(), &tailcfg.DERPRegion{
5658
RegionID: 1,
57-
}, []string{}, server.URL)
59+
}, []string{}, server.URL, "")
5860
require.Error(t, err)
5961
})
62+
t.Run("LocalPath", func(t *testing.T) {
63+
t.Parallel()
64+
localPath := filepath.Join(t.TempDir(), "derp.json")
65+
content, err := json.Marshal(&tailcfg.DERPMap{
66+
Regions: map[int]*tailcfg.DERPRegion{
67+
1: {},
68+
},
69+
})
70+
require.NoError(t, err)
71+
err = os.WriteFile(localPath, content, 0600)
72+
require.NoError(t, err)
73+
derpMap, err := tailnet.NewDERPMap(context.Background(), &tailcfg.DERPRegion{
74+
RegionID: 2,
75+
}, []string{}, "", localPath)
76+
require.NoError(t, err)
77+
require.Len(t, derpMap.Regions, 2)
78+
})
6079
}

0 commit comments

Comments
 (0)