From 9a9d11bb75010f43d771bf0449d462bc153760ce Mon Sep 17 00:00:00 2001
From: David McMahon <djmm@google.com>
Date: Wed, 8 Nov 2017 15:37:49 -0800
Subject: [PATCH] Capture git export-subst strings in version.sh for 'git
 archive' use.

Eliminate the need to update pkg/version/base.go on release branch tagging.
---
 hack/lib/.gitattributes                          |  1 +
 hack/lib/version.sh                              | 13 +++++++++++++
 pkg/version/base.go                              |  8 ++++++--
 staging/src/k8s.io/client-go/pkg/version/base.go |  8 ++++++--
 4 files changed, 26 insertions(+), 4 deletions(-)
 create mode 100644 hack/lib/.gitattributes

diff --git a/hack/lib/.gitattributes b/hack/lib/.gitattributes
new file mode 100644
index 000000000000..1f211b5ce608
--- /dev/null
+++ b/hack/lib/.gitattributes
@@ -0,0 +1 @@
+version.sh export-subst
diff --git a/hack/lib/version.sh b/hack/lib/version.sh
index 7a1d676e5a72..3dab71052af4 100644
--- a/hack/lib/version.sh
+++ b/hack/lib/version.sh
@@ -36,6 +36,19 @@ kube::version::get_version_vars() {
     return
   fi
 
+  # If the kubernetes source was exported through git archive, then
+  # we likely don't have a git tree, but these magic values may be filled in.
+  if [[ '$Format:%%$' == "%" ]]; then
+    KUBE_GIT_COMMIT='$Format:%H$'
+    KUBE_GIT_TREE_STATE="git archive"
+    # When a 'git archive' is exported, the '$Format:%D$' below will look
+    # something like 'HEAD -> release-1.8, tag: v1.8.3' where then 'tag: '
+    # can be extracted from it.
+    if [[ '$Format:%D$' =~ tag:\ (v[^ ]+) ]]; then
+     KUBE_GIT_VERSION="${BASH_REMATCH[1]}"
+    fi
+  fi
+
   local git=(git --work-tree "${KUBE_ROOT}")
 
   if [[ -n ${KUBE_GIT_COMMIT-} ]] || KUBE_GIT_COMMIT=$("${git[@]}" rev-parse "HEAD^{commit}" 2>/dev/null); then
diff --git a/pkg/version/base.go b/pkg/version/base.go
index 6239d53ff850..730e79f03d14 100644
--- a/pkg/version/base.go
+++ b/pkg/version/base.go
@@ -51,9 +51,13 @@ var (
 	// semantic version is a git hash, but the version itself is no
 	// longer the direct output of "git describe", but a slight
 	// translation to be semver compliant.
+
+	// NOTE: The $Format strings are replaced during 'git archive' thanks to the
+	// companion .gitattributes file containing 'export-subst' in this same
+	// directory.  See also https://git-scm.com/docs/gitattributes
 	gitVersion   = "v0.0.0-master+$Format:%h$"
-	gitCommit    = "$Format:%H$"    // sha1 from git, output of $(git rev-parse HEAD)
-	gitTreeState = "not a git tree" // state of git tree, either "clean" or "dirty"
+	gitCommit    = "$Format:%H$" // sha1 from git, output of $(git rev-parse HEAD)
+	gitTreeState = ""            // state of git tree, either "clean" or "dirty"
 
 	buildDate = "1970-01-01T00:00:00Z" // build date in ISO8601 format, output of $(date -u +'%Y-%m-%dT%H:%M:%SZ')
 )
diff --git a/staging/src/k8s.io/client-go/pkg/version/base.go b/staging/src/k8s.io/client-go/pkg/version/base.go
index c377705fe8f1..7ab0ed3a7c64 100644
--- a/staging/src/k8s.io/client-go/pkg/version/base.go
+++ b/staging/src/k8s.io/client-go/pkg/version/base.go
@@ -51,9 +51,13 @@ var (
 	// semantic version is a git hash, but the version itself is no
 	// longer the direct output of "git describe", but a slight
 	// translation to be semver compliant.
+
+	// NOTE: The $Format strings are replaced during 'git archive' thanks to the
+	// companion .gitattributes file containing 'export-subst' in this same
+	// directory.  See also https://git-scm.com/docs/gitattributes
 	gitVersion   string = "v0.0.0-master+$Format:%h$"
-	gitCommit    string = "$Format:%H$"    // sha1 from git, output of $(git rev-parse HEAD)
-	gitTreeState string = "not a git tree" // state of git tree, either "clean" or "dirty"
+	gitCommit    string = "$Format:%H$" // sha1 from git, output of $(git rev-parse HEAD)
+	gitTreeState string = ""            // state of git tree, either "clean" or "dirty"
 
 	buildDate string = "1970-01-01T00:00:00Z" // build date in ISO8601 format, output of $(date -u +'%Y-%m-%dT%H:%M:%SZ')
 )