diff --git a/README.md b/README.md
index 86f98e77a..c882dab3a 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,18 @@ wrappers that are not open source.
go install tailscale.com/cmd/tailscale{,d}
```
+If you're packaging Tailscale for distribution, use `build_dist.sh`
+instead, to burn commit IDs and version info into the binaries:
+
+```
+./build_dist.sh tailscale.com/cmd/tailscale
+./build_dist.sh tailscale.com/cmd/tailscaled
+```
+
+If your distro has conventions that preclude the use of
+`build_dist.sh`, please do the equivalent of what it does in your
+distro's way, so that bug reports contain useful version information.
+
We only guarantee to support the latest Go release and any Go beta or
release candidate builds (currently Go 1.15) in module mode. It might
work in earlier Go versions or in GOPATH mode, but we're making no
diff --git a/build_dist.sh b/build_dist.sh
new file mode 100755
index 000000000..3818a6207
--- /dev/null
+++ b/build_dist.sh
@@ -0,0 +1,22 @@
+#!/usr/bin/env sh
+#
+# Runs `go build` with flags configured for binary distribution. All
+# it does differently from `go build` is burn git commit and version
+# information into the binaries, so that we can track down user
+# issues.
+#
+# If you're packaging Tailscale for a distro, please consider using
+# this script, or executing equivalent commands in your
+# distro-specific build system.
+
+set -euo pipefail
+
+describe=$(git describe --long --abbrev=9)
+# --abbrev=200 is an arbitrary large number to capture the entire git
+# hash without trying to compact it.
+commit=$(git describe --dirty --exclude "*" --always --abbrev=200)
+
+long=$(./version/mkversion.sh long "$describe" "")
+short=$(./version/mkversion.sh short "$describe" "")
+
+exec go build -tags xversion -ldflags "-X tailscale.com/version.Long=${long} -X tailscale.com/version.Short=${short} -X tailscale.com/version.GitCommit=${commit}" "$@"
diff --git a/cmd/derper/derper.go b/cmd/derper/derper.go
index fda0333a6..9fafe210c 100644
--- a/cmd/derper/derper.go
+++ b/cmd/derper/derper.go
@@ -233,7 +233,7 @@ func debugHandler(s *derp.Server) http.Handler {
f("Hostname: %v\n", html.EscapeString(*hostname))
f("Uptime: %v\n", tsweb.Uptime())
f("Mesh Key: %v\n", s.HasMeshKey())
- f("Version: %v\n", html.EscapeString(version.LONG))
+ f("Version: %v\n", html.EscapeString(version.Long))
f(`/debug/vars (Go)
/debug/varz (Prometheus)
diff --git a/cmd/tailscale/cli/version.go b/cmd/tailscale/cli/version.go
index f34671486..a6bbb6912 100644
--- a/cmd/tailscale/cli/version.go
+++ b/cmd/tailscale/cli/version.go
@@ -36,10 +36,11 @@ func runVersion(ctx context.Context, args []string) error {
log.Fatalf("too many non-flag arguments: %q", args)
}
if !versionArgs.daemon {
- fmt.Println(version.LONG)
+ fmt.Println(version.String())
return nil
}
- fmt.Printf("Client: %s\n", version.LONG)
+
+ fmt.Printf("Client: %s\n", version.String())
c, bc, ctx, cancel := connect(ctx)
defer cancel()
diff --git a/cmd/tailscaled/depaware.txt b/cmd/tailscaled/depaware.txt
index ee054bfdc..2c719afb4 100644
--- a/cmd/tailscaled/depaware.txt
+++ b/cmd/tailscaled/depaware.txt
@@ -84,7 +84,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
tailscale.com/types/structs from tailscale.com/control/controlclient+
tailscale.com/util/lineread from tailscale.com/control/controlclient+
tailscale.com/util/pidowner from tailscale.com/ipn/ipnserver
- tailscale.com/version from tailscale.com/control/controlclient+
+ tailscale.com/version from tailscale.com/cmd/tailscaled+
tailscale.com/version/distro from tailscale.com/control/controlclient+
tailscale.com/wgengine from tailscale.com/cmd/tailscaled+
tailscale.com/wgengine/filter from tailscale.com/control/controlclient+
diff --git a/cmd/tailscaled/tailscaled.go b/cmd/tailscaled/tailscaled.go
index e09f59c90..47e02d27e 100644
--- a/cmd/tailscaled/tailscaled.go
+++ b/cmd/tailscaled/tailscaled.go
@@ -12,6 +12,7 @@ package main // import "tailscale.com/cmd/tailscaled"
import (
"context"
"flag"
+ "fmt"
"log"
"net/http"
"net/http/pprof"
@@ -29,6 +30,7 @@ import (
"tailscale.com/paths"
"tailscale.com/types/flagtype"
"tailscale.com/types/logger"
+ "tailscale.com/version"
"tailscale.com/wgengine"
"tailscale.com/wgengine/magicsock"
"tailscale.com/wgengine/router"
@@ -73,6 +75,7 @@ func main() {
debug.SetGCPercent(10)
}
+ printVersion := false
flag.BoolVar(&args.cleanup, "cleanup", false, "clean up system state and exit")
flag.BoolVar(&args.fake, "fake", false, "use userspace fake tunnel+routing instead of kernel TUN interface")
flag.StringVar(&args.debug, "debug", "", "listen address ([ip]:port) of optional debug server")
@@ -80,6 +83,7 @@ func main() {
flag.Var(flagtype.PortValue(&args.port, magicsock.DefaultPort), "port", "UDP port to listen on for WireGuard and peer-to-peer traffic; 0 means automatically select")
flag.StringVar(&args.statepath, "state", paths.DefaultTailscaledStateFile(), "path of state file")
flag.StringVar(&args.socketpath, "socket", paths.DefaultTailscaledSocket(), "path of the service unix socket")
+ flag.BoolVar(&printVersion, "version", false, "print version information and exit")
err := fixconsole.FixConsoleIfNeeded()
if err != nil {
@@ -91,6 +95,11 @@ func main() {
log.Fatalf("tailscaled does not take non-flag arguments: %q", flag.Args())
}
+ if printVersion {
+ fmt.Println(version.String())
+ os.Exit(0)
+ }
+
if args.statepath == "" {
log.Fatalf("--state is required")
}
diff --git a/control/controlclient/direct.go b/control/controlclient/direct.go
index e5f2c3de7..97d45d2d2 100644
--- a/control/controlclient/direct.go
+++ b/control/controlclient/direct.go
@@ -206,7 +206,7 @@ func NewHostinfo() *tailcfg.Hostinfo {
osv = osVersion()
}
return &tailcfg.Hostinfo{
- IPNVersion: version.LONG,
+ IPNVersion: version.Long,
Hostname: hostname,
OS: version.OS(),
OSVersion: osv,
diff --git a/derp/derp_server.go b/derp/derp_server.go
index d0ed16b17..104dc11bf 100644
--- a/derp/derp_server.go
+++ b/derp/derp_server.go
@@ -1291,7 +1291,7 @@ func (s *Server) ExpVar() expvar.Var {
m.Set("multiforwarder_deleted", &s.multiForwarderDeleted)
m.Set("packet_forwarder_delete_other_value", &s.removePktForwardOther)
var expvarVersion expvar.String
- expvarVersion.Set(version.LONG)
+ expvarVersion.Set(version.Long)
m.Set("version", &expvarVersion)
return m
}
diff --git a/ipn/ipnserver/server.go b/ipn/ipnserver/server.go
index 4e00e6a01..86a96008c 100644
--- a/ipn/ipnserver/server.go
+++ b/ipn/ipnserver/server.go
@@ -473,7 +473,7 @@ func Run(ctx context.Context, logf logger.Logf, logid string, getEngine func() (
if opts.AutostartStateKey != "" {
server.bs.GotCommand(&ipn.Command{
- Version: version.LONG,
+ Version: version.Long,
Start: &ipn.StartArgs{
Opts: ipn.Options{
StateKey: opts.AutostartStateKey,
diff --git a/ipn/local.go b/ipn/local.go
index b8c9d6da3..e3c261903 100644
--- a/ipn/local.go
+++ b/ipn/local.go
@@ -671,7 +671,7 @@ func (b *LocalBackend) send(n Notify) {
b.mu.Unlock()
if notify != nil {
- n.Version = version.LONG
+ n.Version = version.Long
notify(n)
} else {
b.logf("nil notify callback; dropping %+v", n)
@@ -945,7 +945,7 @@ func (b *LocalBackend) parseWgStatus(s *wgengine.Status) (ret EngineStatus) {
// [GRINDER STATS LINE] - please don't remove (used for log parsing)
b.keyLogf("peer keys: %s", strings.Join(peerKeys, " "))
// [GRINDER STATS LINE] - please don't remove (used for log parsing)
- b.logf("v%v peers: %v", version.LONG, strings.Join(peerStats, " "))
+ b.logf("v%v peers: %v", version.Long, strings.Join(peerStats, " "))
}
return ret
}
diff --git a/ipn/message.go b/ipn/message.go
index 4e672e4fc..77bb9deaa 100644
--- a/ipn/message.go
+++ b/ipn/message.go
@@ -80,7 +80,7 @@ func NewBackendServer(logf logger.Logf, b Backend, sendNotifyMsg func(b []byte))
}
func (bs *BackendServer) send(n Notify) {
- n.Version = version.LONG
+ n.Version = version.Long
b, err := json.Marshal(n)
if err != nil {
log.Fatalf("Failed json.Marshal(notify): %v\n%#v", err, n)
@@ -106,14 +106,14 @@ func (bs *BackendServer) GotCommandMsg(b []byte) error {
}
func (bs *BackendServer) GotFakeCommand(cmd *Command) error {
- cmd.Version = version.LONG
+ cmd.Version = version.Long
return bs.GotCommand(cmd)
}
func (bs *BackendServer) GotCommand(cmd *Command) error {
- if cmd.Version != version.LONG && !cmd.AllowVersionSkew {
+ if cmd.Version != version.Long && !cmd.AllowVersionSkew {
vs := fmt.Sprintf("GotCommand: Version mismatch! frontend=%#v backend=%#v",
- cmd.Version, version.LONG)
+ cmd.Version, version.Long)
bs.logf("%s", vs)
// ignore the command, but send a message back to the
// caller so it can realize the version mismatch too.
@@ -197,9 +197,9 @@ func (bc *BackendClient) GotNotifyMsg(b []byte) {
if err := json.Unmarshal(b, &n); err != nil {
log.Fatalf("BackendClient.Notify: cannot decode message (length=%d)\n%#v", len(b), string(b))
}
- if n.Version != version.LONG && !bc.AllowVersionSkew {
+ if n.Version != version.Long && !bc.AllowVersionSkew {
vs := fmt.Sprintf("GotNotify: Version mismatch! frontend=%#v backend=%#v",
- version.LONG, n.Version)
+ version.Long, n.Version)
bc.logf("%s", vs)
// delete anything in the notification except the version,
// to prevent incorrect operation.
@@ -214,7 +214,7 @@ func (bc *BackendClient) GotNotifyMsg(b []byte) {
}
func (bc *BackendClient) send(cmd Command) {
- cmd.Version = version.LONG
+ cmd.Version = version.Long
b, err := json.Marshal(cmd)
if err != nil {
log.Fatalf("Failed json.Marshal(cmd): %v\n%#v\n", err, cmd)
diff --git a/logpolicy/logpolicy.go b/logpolicy/logpolicy.go
index f57b6447d..632cdc1ca 100644
--- a/logpolicy/logpolicy.go
+++ b/logpolicy/logpolicy.go
@@ -395,7 +395,7 @@ func New(collection string) *Policy {
log.SetOutput(lw)
log.Printf("Program starting: v%v, Go %v: %#v",
- version.LONG,
+ version.Long,
strings.TrimPrefix(runtime.Version(), "go"),
os.Args)
log.Printf("LogID: %v", newc.PublicID)
diff --git a/version/.gitignore b/version/.gitignore
index 47d66053b..60df6e2d6 100644
--- a/version/.gitignore
+++ b/version/.gitignore
@@ -1,6 +1,8 @@
describe.txt
long.txt
short.txt
+gitcommit.txt
+extragitcommit.txt
version.h
version.xcconfig
ver.go
diff --git a/version/describe.txt.do b/version/describe.txt.do
index 0df15345f..0bdf6651a 100644
--- a/version/describe.txt.do
+++ b/version/describe.txt.do
@@ -1,4 +1,4 @@
-describe=$(cd ../.. && git describe --long --abbrev=9)
+describe=$(git describe --long --abbrev=9)
echo "$describe" >$3
redo-always
redo-stamp <$3
diff --git a/version/extragitcommit.txt.do b/version/extragitcommit.txt.do
new file mode 100644
index 000000000..d494fd04f
--- /dev/null
+++ b/version/extragitcommit.txt.do
@@ -0,0 +1,6 @@
+# --abbrev=200 is an arbitrary large number to capture the entire git
+# hash without trying to compact it.
+commit=$(cd ../.. && git describe --dirty --exclude "*" --always --abbrev=200)
+echo "$commit" >$3
+redo-always
+redo-stamp <$3
diff --git a/version/gitcommit.txt.do b/version/gitcommit.txt.do
new file mode 100644
index 000000000..f943fa8bf
--- /dev/null
+++ b/version/gitcommit.txt.do
@@ -0,0 +1,6 @@
+# --abbrev=200 is an arbitrary large number to capture the entire git
+# hash without trying to compact it.
+commit=$(git describe --dirty --exclude "*" --always --abbrev=200)
+echo "$commit" >$3
+redo-always
+redo-stamp <$3
diff --git a/version/long.txt.do b/version/long.txt.do
index f88bcf7ff..96bd18377 100644
--- a/version/long.txt.do
+++ b/version/long.txt.do
@@ -1,4 +1,5 @@
-redo-ifchange mkversion.sh describe.txt
+redo-ifchange mkversion.sh describe.txt extragitcommit.txt
read -r describe $3
diff --git a/version/mkversion.sh b/version/mkversion.sh
index 41c214850..a5768c040 100755
--- a/version/mkversion.sh
+++ b/version/mkversion.sh
@@ -4,6 +4,7 @@ set -eu
mode=$1
describe=$2
+other=$3
# Git describe output overall looks like
# MAJOR.MINOR.PATCH-NUMCOMMITS-GITHASH. Depending on the tag being
@@ -55,6 +56,25 @@ case "$suffix" in
;;
esac
+# The git hash is of the form "gCOMMITHASH". We want to replace the
+# 'g' with a 't', for "tailscale", to convey that it's specifically
+# the commit hash of the tailscale repo.
+if [ -n "$githash" ]; then
+ # POSIX shell doesn't understand ${foo:1:9} syntax, gaaah.
+ githash="$(echo $githash | cut -c2-10)"
+ githash="t${githash}"
+fi
+
+# "other" is a second git commit hash for another repository used to
+# build the Tailscale code. In practice it's either the commit hash in
+# the Android repository, or the commit hash of Tailscale's
+# proprietary repository (which pins a bunch things like build scripts
+# used and Go toolchain version).
+if [ -n "$other" ]; then
+ other="$(echo $other | cut -c1-9)"
+ other="-o${other}"
+fi
+
# Validate that the version data makes sense. Rules:
# - Odd number minors are unstable. Patch must be 0, and gets
# replaced by changecount.
@@ -82,15 +102,23 @@ else
# pbulic, but it's useful to be able to build it for
# debugging. Just force the version to 0.0.0, so that we're
# forced to rely on the git commit hash.
- major=0
- minor=0
- patch=0
+ major="0"
+ minor="0"
+ patch="0"
fi
fi
+if [ "$minor" -eq 1 ]; then
+ # Hack for 1.1: add 1000 to the patch number, so that builds that
+ # use the OSS change count order after the builds that used the
+ # proprietary repo's changecount. Otherwise, the version numbers
+ # would go backwards and things would be unhappy.
+ patch=$((patch + 1000))
+fi
+
case "$1" in
long)
- echo "${major}.${minor}.${patch}-${githash}"
+ echo "${major}.${minor}.${patch}-${githash}${other}"
;;
short)
echo "${major}.${minor}.${patch}"
diff --git a/version/mkversion_test.go b/version/mkversion_test.go
index c670b4989..00560bbf1 100644
--- a/version/mkversion_test.go
+++ b/version/mkversion_test.go
@@ -16,9 +16,9 @@ func xcode(short, long string) string {
return fmt.Sprintf("VERSION_NAME = %s\nVERSION_ID = %s", short, long)
}
-func mkversion(t *testing.T, mode, in string) (string, bool) {
+func mkversion(t *testing.T, mode, describe, other string) (string, bool) {
t.Helper()
- bs, err := exec.Command("./mkversion.sh", mode, in).CombinedOutput()
+ bs, err := exec.Command("./mkversion.sh", mode, describe, other).CombinedOutput()
if err != nil {
t.Logf("mkversion.sh output: %s", string(bs))
return "", false
@@ -31,49 +31,50 @@ func TestMkversion(t *testing.T) {
t.Skip("skip test on Windows, because there is no shell to execute mkversion.sh.")
}
tests := []struct {
- in string
- ok bool
- long string
- short string
- xcode string
+ describe string
+ other string
+ ok bool
+ long string
+ short string
+ xcode string
}{
- {"v0.98-abcdef", true, "0.98.0-abcdef", "0.98.0", xcode("0.98.0", "100.98.0")},
- {"v0.98.1-abcdef", true, "0.98.1-abcdef", "0.98.1", xcode("0.98.1", "100.98.1")},
- {"v1.1.0-37-abcdef", true, "1.1.37-abcdef", "1.1.37", xcode("1.1.37", "101.1.37")},
- {"v1.2.9-abcdef", true, "1.2.9-abcdef", "1.2.9", xcode("1.2.9", "101.2.9")},
- {"v1.2.9-0-abcdef", true, "1.2.9-abcdef", "1.2.9", xcode("1.2.9", "101.2.9")},
- {"v1.15.0-129-abcdef", true, "1.15.129-abcdef", "1.15.129", xcode("1.15.129", "101.15.129")},
+ {"v0.98-gabcdef", "", true, "0.98.0-tabcdef", "0.98.0", xcode("0.98.0", "100.98.0")},
+ {"v0.98.1-gabcdef", "", true, "0.98.1-tabcdef", "0.98.1", xcode("0.98.1", "100.98.1")},
+ {"v1.1.0-37-gabcdef", "", true, "1.1.1037-tabcdef", "1.1.1037", xcode("1.1.1037", "101.1.1037")},
+ {"v1.2.9-gabcdef", "", true, "1.2.9-tabcdef", "1.2.9", xcode("1.2.9", "101.2.9")},
+ {"v1.2.9-0-gabcdef", "", true, "1.2.9-tabcdef", "1.2.9", xcode("1.2.9", "101.2.9")},
+ {"v1.15.0-129-gabcdef", "", true, "1.15.129-tabcdef", "1.15.129", xcode("1.15.129", "101.15.129")},
- {"v0.98-123-abcdef", true, "0.0.0-abcdef", "0.0.0", xcode("0.0.0", "100.0.0")},
- {"v1.0.0-37-abcdef", true, "0.0.0-abcdef", "0.0.0", xcode("0.0.0", "100.0.0")},
-
- {"v0.99.5-0-abcdef", false, "", "", ""}, // unstable, patch not allowed
- {"v0.99.5-123-abcdef", false, "", "", ""}, // unstable, patch not allowed
- {"v1-abcdef", false, "", "", ""}, // bad semver
- {"v1.0", false, "", "", ""}, // missing suffix
+ {"v0.98-123-gabcdef", "", true, "0.0.0-tabcdef", "0.0.0", xcode("0.0.0", "100.0.0")},
+ {"v1.0.0-37-gabcdef", "", true, "0.0.0-tabcdef", "0.0.0", xcode("0.0.0", "100.0.0")},
+ {"v1.1.0-129-gabcdef", "0123456789abcdef0123456789abcdef", true, "1.1.1129-tabcdef-o012345678", "1.1.1129", xcode("1.1.1129", "101.1.1129")},
+ {"v0.99.5-0-gabcdef", "", false, "", "", ""}, // unstable, patch not allowed
+ {"v0.99.5-123-gabcdef", "", false, "", "", ""}, // unstable, patch not allowed
+ {"v1-gabcdef", "", false, "", "", ""}, // bad semver
+ {"v1.0", "", false, "", "", ""}, // missing suffix
}
for _, test := range tests {
- gotlong, longOK := mkversion(t, "long", test.in)
+ gotlong, longOK := mkversion(t, "long", test.describe, test.other)
if longOK != test.ok {
- t.Errorf("mkversion.sh long %q ok=%v, want %v", test.in, longOK, test.ok)
+ t.Errorf("mkversion.sh long %q ok=%v, want %v", test.describe, longOK, test.ok)
}
- gotshort, shortOK := mkversion(t, "short", test.in)
+ gotshort, shortOK := mkversion(t, "short", test.describe, test.other)
if shortOK != test.ok {
- t.Errorf("mkversion.sh short %q ok=%v, want %v", test.in, shortOK, test.ok)
+ t.Errorf("mkversion.sh short %q ok=%v, want %v", test.describe, shortOK, test.ok)
}
- gotxcode, xcodeOK := mkversion(t, "xcode", test.in)
+ gotxcode, xcodeOK := mkversion(t, "xcode", test.describe, test.other)
if xcodeOK != test.ok {
- t.Errorf("mkversion.sh xcode %q ok=%v, want %v", test.in, xcodeOK, test.ok)
+ t.Errorf("mkversion.sh xcode %q ok=%v, want %v", test.describe, xcodeOK, test.ok)
}
if longOK && gotlong != test.long {
- t.Errorf("mkversion.sh long %q: got %q, want %q", test.in, gotlong, test.long)
+ t.Errorf("mkversion.sh long %q: got %q, want %q", test.describe, gotlong, test.long)
}
if shortOK && gotshort != test.short {
- t.Errorf("mkversion.sh short %q: got %q, want %q", test.in, gotshort, test.short)
+ t.Errorf("mkversion.sh short %q: got %q, want %q", test.describe, gotshort, test.short)
}
if xcodeOK && gotxcode != test.xcode {
- t.Errorf("mkversion.sh xcode %q: got %q, want %q", test.in, gotxcode, test.xcode)
+ t.Errorf("mkversion.sh xcode %q: got %q, want %q", test.describe, gotxcode, test.xcode)
}
}
}
diff --git a/version/print.go b/version/print.go
new file mode 100644
index 000000000..800f8f128
--- /dev/null
+++ b/version/print.go
@@ -0,0 +1,25 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package version
+
+import (
+ "fmt"
+ "runtime"
+ "strings"
+)
+
+func String() string {
+ var ret strings.Builder
+ ret.WriteString(Short)
+ ret.WriteByte('\n')
+ if GitCommit != "" {
+ fmt.Fprintf(&ret, " tailscale commit: %s\n", GitCommit)
+ }
+ if ExtraGitCommit != "" {
+ fmt.Fprintf(&ret, " other commit: %s\n", ExtraGitCommit)
+ }
+ fmt.Fprintf(&ret, " go version: %s\n", runtime.Version())
+ return strings.TrimSpace(ret.String())
+}
diff --git a/version/short.txt.do b/version/short.txt.do
index 8a189f638..ca9426b60 100644
--- a/version/short.txt.do
+++ b/version/short.txt.do
@@ -1,4 +1,5 @@
-redo-ifchange mkversion.sh describe.txt
+redo-ifchange mkversion.sh describe.txt extragitcommit.txt
read -r describe $3
diff --git a/version/ver.go.do b/version/ver.go.do
index f7a8e1f6d..28a1bab79 100644
--- a/version/ver.go.do
+++ b/version/ver.go.do
@@ -1,8 +1,12 @@
-redo-ifchange long.txt short.txt ver.go.in
+redo-ifchange long.txt short.txt gitcommit.txt extragitcommit.txt ver.go.in
read -r LONGVER $3
diff --git a/version/ver.go.in b/version/ver.go.in
index 7d8c308a5..dc5cbcecf 100644
--- a/version/ver.go.in
+++ b/version/ver.go.in
@@ -6,5 +6,9 @@
package version
-const LONG = "{LONGVER}"
-const SHORT = "{SHORTVER}"
+const Long = "{LONGVER}"
+const Short = "{SHORTVER}"
+const LONG = Long
+const SHORT = Short
+const GitCommit = "{GITCOMMIT}"
+const ExtraGitCommit = "{EXTRAGITCOMMIT}"
diff --git a/version/version.go b/version/version.go
index 734358023..fef7a326d 100644
--- a/version/version.go
+++ b/version/version.go
@@ -7,5 +7,35 @@
// Package version provides the version that the binary was built at.
package version
-const LONG = "date.20200921"
-const SHORT = LONG
+// Long is a full version number for this build, of the form
+// "x.y.z-commithash", or "date.yyyymmdd" if no actual version was
+// provided.
+const Long = "date.20200921"
+
+// Short is a short version number for this build, of the form
+// "x.y.z", or "date.yyyymmdd" if no actual version was provided.
+const Short = Long
+
+// LONG is a deprecated alias for Long. Don't use it.
+const LONG = Long
+
+// SHORT is a deprecated alias for Short. Don't use it.
+const SHORT = Short
+
+// GitCommit, if non-empty, is the git commit of the
+// github.com/tailscale/tailscale repository at which Tailscale was
+// built. Its format is the one returned by `git describe --always
+// --exclude "*" --dirty --abbrev=200`.
+const GitCommit = ""
+
+// ExtraGitCommit, if non-empty, is the git commit of a "supplemental"
+// repository at which Tailscale was built. Its format is the same as
+// GitRevision.
+//
+// ExtraGitRevision is used to track the source revision when the main
+// Tailscale repository is integrated into and built from another
+// repository (for example, Tailscale's proprietary code, or the
+// Android OSS repository). Together, GitRevision and ExtraGitRevision
+// exactly describe what repositories and commits were used in a
+// build.
+const ExtraGitCommit = ""
diff --git a/version/version.xcconfig.do b/version/version.xcconfig.do
index cda65b06a..2cdf533e7 100644
--- a/version/version.xcconfig.do
+++ b/version/version.xcconfig.do
@@ -1,4 +1,5 @@
-redo-ifchange mkversion.sh describe.txt
+redo-ifchange mkversion.sh describe.txt extragitcommit.txt
read -r describe $3
diff --git a/version/xversion.go b/version/xversion.go
index 50e2b30b8..05b66dc20 100644
--- a/version/xversion.go
+++ b/version/xversion.go
@@ -6,6 +6,12 @@
package version
-// Replaced at build time with the Go linker flag -X.
-var LONG string = ""
-var SHORT string = ""
+// Replaced at build time with the Go linker flag -X. See
+// ../build_dist.sh for example usage, and version.go for field
+// documentation.
+var Long string = ""
+var Short string = ""
+var LONG = Long
+var SHORT = Short
+var GitCommit = ""
+var ExtraGitCommit = ""