From 4a663468e6981d8fbda834458c38b1792d542b2d Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Thu, 19 Sep 2024 12:40:00 -0700
Subject: [PATCH] [tailscale] runtime/debug: embed Tailscale toolchain git rev

This is another take on #49 (which we stopped using?), and less
intrusive, and also always on.

This puts puts the the Tailscale Go toolchain's git rev in
the binary, accessible as runtime/debug.TailscaleGitRev.

Caller code will have to access it guarded by the "tailscale_go" build
tag.

Updates #49

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
 .github/workflows/build.yml | 2 ++
 api/go1.99999.txt           | 2 ++
 src/runtime/debug/mod.go    | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4972a145ee388b..4689fe93dcab86 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -41,6 +41,8 @@ jobs:
       uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
       with:
         ref: ${{ inputs.ref || github.ref }}
+    - name: set runtime/debug.TailscaleGitRev
+      run: sed -i "s/TAILSCALE_GIT_REV_TO_BE_REPLACED_AT_BUILD_TIME/${{ github.sha }}/" src/runtime/debug/tailscale-git-rev.txt
     - name: build
       run: cd src && ./make.bash
       env:
diff --git a/api/go1.99999.txt b/api/go1.99999.txt
index dd6ab70a2079fd..b05358550eabd2 100644
--- a/api/go1.99999.txt
+++ b/api/go1.99999.txt
@@ -9,3 +9,5 @@ pkg net, type SockTrace struct, DidWrite func(int) #58
 pkg net, type SockTrace struct, WillCloseTCPConn func(syscall.RawConn) #58
 pkg net, type SockTrace struct, WillOverwrite func(*SockTrace) #58
 pkg net/http, func SetRoundTripEnforcer(func(*Request) error) #55
+pkg runtime/debug, const TailscaleGitRev = "TAILSCALE_GIT_REV_TO_BE_REPLACED_AT_BUILD_TIME" #104
+pkg runtime/debug, const TailscaleGitRev ideal-string #104
diff --git a/src/runtime/debug/mod.go b/src/runtime/debug/mod.go
index a4705605b859a1..7e170391f9e71c 100644
--- a/src/runtime/debug/mod.go
+++ b/src/runtime/debug/mod.go
@@ -11,6 +11,8 @@ import (
 	"strings"
 )
 
+const TailscaleGitRev = `TAILSCALE_GIT_REV_TO_BE_REPLACED_AT_BUILD_TIME`
+
 // exported from runtime.
 func modinfo() string