Make skipping logic more robust in hack/verify-godep*

Also add an environment variable, KUBE_VERIFY_GIT_BRANCH, used with this
logic.

hack/jenkins/gotest-dockerized.sh

@@ -21,9 +21,6 @@ set -o xtrace
 
 export REPO_DIR=${REPO_DIR:-$(pwd)}
 
-# Produce a JUnit-style XML test report for Jenkins.
-export KUBE_JUNIT_REPORT_DIR=${WORKSPACE}/_artifacts
-
 # Run the kubekins container, mapping in docker (so we can launch containers),
 # the repo directory, and the artifacts output directory.
 #
@@ -40,8 +37,9 @@ docker run --rm=true \
   -v /var/run/docker.sock:/var/run/docker.sock \
   -v "$(which docker)":/bin/docker \
   -v "${REPO_DIR}":/go/src/k8s.io/kubernetes \
-  -v "${KUBE_JUNIT_REPORT_DIR}":/workspace/artifacts \
+  -v "${WORKSPACE}/_artifacts":/workspace/artifacts \
   -v /etc/localtime:/etc/localtime:ro \
-  --env REPO_DIR="${REPO_DIR}" \
+  -e "KUBE_VERIFY_GIT_BRANCH=${KUBE_VERIFY_GIT_BRANCH:-}" \
+  -e "REPO_DIR=${REPO_DIR}" \
   -i gcr.io/google_containers/kubekins-test:0.7 \
   bash -c "cd kubernetes && ./hack/jenkins/test-dockerized.sh"

hack/jenkins/job-configs/kubernetes-jenkins/kubernetes-test-go.yaml

@@ -9,6 +9,7 @@
     builders:
         - shell: 'bash <(curl -fsS --retry 3 "https://raw.githubusercontent.com/kubernetes/kubernetes/master/hack/jenkins/upload-started.sh")'
         - shell: |
+            export KUBE_VERIFY_GIT_BRANCH='{branch}'
             timeout -k {kill-timeout}m {timeout}m ./hack/jenkins/gotest-dockerized.sh && rc=$? || rc=$?
             {report-rc}
     publishers:

hack/verify-godep-licenses.sh

@@ -20,9 +20,15 @@ set -o pipefail
 
 KUBE_ROOT="$(cd "$(dirname "${BASH_SOURCE}")/.." && pwd -P)"
 
-branch="${1:-master}"
+readonly branch="origin/${1:-${KUBE_VERIFY_GIT_BRANCH:-master}}"
+echo "Checking for Godeps changes against ${branch}"
+# make sure the branch is valid, otherwise the next check will pass erroneously.
+if ! git describe "${branch}" >/dev/null; then
+  exit 1
+fi
 # notice this uses ... to find the first shared ancestor
-if ! git diff origin/"${branch}"...HEAD | grep 'Godeps/' > /dev/null; then
+if ! git diff --name-only "${branch}...HEAD" | grep 'Godeps/' > /dev/null; then
+  echo "No Godeps changes detected."
   exit 0
 fi
 

hack/verify-godeps.sh

@@ -39,9 +39,15 @@ preload-dep() {
 KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
 source "${KUBE_ROOT}/hack/lib/init.sh"
 
-branch="${1:-master}"
+readonly branch="origin/${1:-${KUBE_VERIFY_GIT_BRANCH:-master}}"
+echo "Checking for Godeps changes against ${branch}"
+# make sure the branch is valid, otherwise the next check will pass erroneously.
+if ! git describe "${branch}" >/dev/null; then
+  exit 1
+fi
 # notice this uses ... to find the first shared ancestor
-if ! git diff origin/"${branch}"...HEAD | grep 'Godeps/' > /dev/null; then
+if ! git diff --name-only "${branch}...HEAD" | grep 'Godeps/' > /dev/null; then
+  echo "No Godeps changes detected."
   exit 0
 fi