Makefile/scripts: check and use GOBIN environment variable first

'go get/install' will install binaries into GOBIN when it's set which is not
always same with GOPATH/bin

Fix below error:
$ hack/testExamplesAgainstKustomize.sh HEAD
Installing kustomize HEAD
On linux, and not on remote CI.  Running expensive tests.
make: Nothing to be done for '/home/lizj/gosrc/bin/helm'.
Removing kustomize HEAD
rm: cannot remove '/home/lizj/gosrc/bin/kustomize': No such file or directory

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>

Makefile

@@ -3,8 +3,11 @@
 #
 # Makefile for kustomize CLI and API.
 
-MYGOBIN := $(shell go env GOPATH)/bin
 SHELL := /usr/bin/env bash
+MYGOBIN = $(shell go env GOBIN)
+ifeq ($(MYGOBIN),)
+MYGOBIN = $(shell go env GOPATH)/bin
+endif
 export PATH := $(MYGOBIN):$(PATH)
 MODULES := '"cmd/config" "api/" "kustomize/" "kyaml/"'
 

hack/testExamplesAgainstKustomize.sh

@@ -14,9 +14,11 @@ version=$1
 
 echo "Installing kustomize ${version}"
 
+MYGOBIN=$(go env GOBIN)
+MYGOBIN="${MYGOBIN:-$(go env GOPATH)/bin}"
 # Always rebuild, never assume the installed verion is
 # the right one to test.
-rm -f $(go env GOPATH)/bin/kustomize
+rm -f $MYGOBIN/kustomize
 if [ "$version" == "HEAD" ]; then
   (cd kustomize; go install .)
 else
@@ -35,7 +37,7 @@ if onLinuxAndNotOnRemoteCI; then
   echo "On linux, and not on remote CI.  Running expensive tests."
 
   # Requires helm.
-  make $(go env GOPATH)/bin/helm
+  make $MYGOBIN/helm
   mdrip --mode test --label helmtest examples/chart.md
 fi
 
@@ -43,6 +45,6 @@ fi
 # rely on whatever this script just did.  Tests should
 # be order independent.
 echo "Removing kustomize ${version}"
-rm $(go env GOPATH)/bin/kustomize
+rm $MYGOBIN/kustomize
 
 echo "Example tests passed against ${version}."

hack/testUnitKustomizePlugins.sh

@@ -14,6 +14,9 @@ set -o pipefail
 
 rcAccumulator=0
 
+MYGOBIN=$(go env GOBIN)
+MYGOBIN="${MYGOBIN:-$(go env GOPATH)/bin}"
+
 # All hack scripts should run from top level.
 . hack/shellHelpers.sh
 
@@ -49,10 +52,10 @@ function scanDir {
 
 if onLinuxAndNotOnRemoteCI; then
   # Some of these tests have special deps.
-  make $(go env GOPATH)/bin/helmV2
-  make $(go env GOPATH)/bin/helmV3
-  make $(go env GOPATH)/bin/helm
-  make $(go env GOPATH)/bin/kubeval
+  make $MYGOBIN/helmV2
+  make $MYGOBIN/helmV3
+  make $MYGOBIN/helm
+  make $MYGOBIN/kubeval
 fi
 
 for goMod in $(find ./plugin -name 'go.mod' -not -path "./plugin/untested/*"); do