From 660c290bbfb84992e0a7a260caf49780010879a4 Mon Sep 17 00:00:00 2001
From: Jordan Liggitt <liggitt@google.com>
Date: Tue, 23 Jun 2020 16:10:26 -0400
Subject: [PATCH] go1.14: set -mod=mod while rebuilding/linting vendor and
 building licenses, preserve explicit imports in modules.txt

---
 hack/lint-dependencies.sh      |  4 ++--
 hack/update-vendor-licenses.sh |  2 ++
 hack/update-vendor.sh          | 16 ++++++++++++----
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/hack/lint-dependencies.sh b/hack/lint-dependencies.sh
index ca8047ebd08..f607f904b60 100755
--- a/hack/lint-dependencies.sh
+++ b/hack/lint-dependencies.sh
@@ -27,8 +27,8 @@ source "${KUBE_ROOT}/hack/lib/init.sh"
 
 # Explicitly opt into go modules, even though we're inside a GOPATH directory
 export GO111MODULE=on
-# Explicitly clear GOFLAGS, since GOFLAGS=-mod=vendor breaks dependency resolution while rebuilding vendor
-export GOFLAGS=
+# Explicitly set GOFLAGS to ignore vendor, since GOFLAGS=-mod=vendor breaks dependency resolution while rebuilding vendor
+export GOFLAGS=-mod=mod
 # Detect problematic GOPROXY settings that prevent lookup of dependencies
 if [[ "${GOPROXY:-}" == "off" ]]; then
   kube::log::error "Cannot run with \$GOPROXY=off"
diff --git a/hack/update-vendor-licenses.sh b/hack/update-vendor-licenses.sh
index 45567512380..50f40ae6878 100755
--- a/hack/update-vendor-licenses.sh
+++ b/hack/update-vendor-licenses.sh
@@ -134,7 +134,9 @@ process_content () {
 # MAIN
 #############################################################################
 
+# use modules, and use module info rather than the vendor dir for computing dependencies
 export GO111MODULE=on
+export GOFLAGS=-mod=mod
 
 # Check bash version
 if (( BASH_VERSINFO[0] < 4 )); then
diff --git a/hack/update-vendor.sh b/hack/update-vendor.sh
index ae04558109c..ef2c0c47de3 100755
--- a/hack/update-vendor.sh
+++ b/hack/update-vendor.sh
@@ -23,8 +23,8 @@ source "${KUBE_ROOT}/hack/lib/init.sh"
 
 # Explicitly opt into go modules, even though we're inside a GOPATH directory
 export GO111MODULE=on
-# Explicitly clear GOFLAGS, since GOFLAGS=-mod=vendor breaks dependency resolution while rebuilding vendor
-export GOFLAGS=
+# Explicitly set GOFLAGS to ignore vendor, since GOFLAGS=-mod=vendor breaks dependency resolution while rebuilding vendor
+export GOFLAGS=-mod=mod
 # Ensure sort order doesn't depend on locale
 export LANG=C
 export LC_ALL=C
@@ -327,8 +327,16 @@ go mod vendor >>"${LOG_FILE}" 2>&1
 
 # sort recorded packages for a given vendored dependency in modules.txt.
 # `go mod vendor` outputs in imported order, which means slight go changes (or different platforms) can result in a differently ordered modules.txt.
-# scan                 | prefix comment lines with the module name       | sort field 1  | strip leading text on comment lines
-awk '{if($1=="#") print $2 " " $0; else print}' < vendor/modules.txt | sort -k1,1 -s | sed 's/.*#/#/' > "${TMP_DIR}/modules.txt.tmp"
+# 1. prefix '#' lines with the module name and capture the module name
+# 2. prefix '##' with the most recently captured module name
+# 3. output other lines as-is
+# sort lines
+# strip anything before '#'
+awk '{
+  if($1=="#")       { current_module=$2; print $2 " " $0;      }
+  else if($1=="##") { print current_module " " $0; }
+  else              { print }
+}' < vendor/modules.txt | sort -k1,1 -s | sed 's/[^#]*#/#/' > "${TMP_DIR}/modules.txt.tmp"
 mv "${TMP_DIR}/modules.txt.tmp" vendor/modules.txt
 
 # create a symlink in vendor directory pointing to the staging components.