Add scripts to release from travis-ci

.travis/common.sh

@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+
+# Copyright 2017 The Kubernetes Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+if ! [ -z $DEBUG ]; then
+  set -x
+fi
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+# Check if jq binary is installed
+if ! [ -x "$(command -v jq)" ]; then
+  echo "Installing jq..."
+  sudo apt-get install -y jq
+fi
+
+if ! [ "$TRAVIS_REPO_SLUG" == "kubernetes/ingress-nginx" ];
+then
+  echo "Only builds from kubernetes/ingress-nginx repository is allowed.";
+  exit 0;
+fi
+
+# variables QUAY_USERNAME and QUAY_PASSWORD are required to push docker images
+if [ "$QUAY_USERNAME" == "" ];
+then
+  echo "Environment variable QUAY_USERNAME is missing.";
+  exit 0;
+fi
+
+if [ "$QUAY_PASSWORD" == "" ];
+then
+  echo "Environment variable QUAY_PASSWORD is missing.";
+  exit 0;
+fi
+
+SKIP_MESSAGE="Publication of docker image to quay.io registry skipped."
+
+if ! [ "$TRAVIS_EVENT_TYPE" == "api" ];
+then
+  echo "Only builds triggered from travis-ci API is allowed. $SKIP_MESSAGE";
+  exit 0;
+fi
+
+if ! [ "$TRAVIS_PULL_REQUEST" == "false" ];
+then
+  echo "This is a pull request. $SKIP_MESSAGE";
+  exit 0;
+fi
+
+if ! [ "$TRAVIS_PULL_REQUEST_BRANCH" == "master" ];
+then
+  echo "Only images build from master branch are allowed. $SKIP_MESSAGE";
+  exit 0;
+fi
+
+function docker_tag_exists() {
+    TAG=${2//\"/}
+    IMAGES=$(curl -s -H "Authorization: Bearer ${QUAY_PASSWORD}" https://quay.io/api/v1/repository/$1/image/ | jq '.images | sort_by(.sort_index) | .[] .tags | select(.[] !=null) | .[0]' | sed s/\"//g)
+    if echo "$IMAGES" | grep -q "$TAG" ; then
+        return 0
+    fi
+
+    return 1
+}