[ShareChat] Make targets for pushing the image to GCR + the correspon…

…ding README (#2)

Added Makefile and instruction / protocol in the README.

Makefile

@@ -0,0 +1,52 @@
+###############################################################################
+#  Licensed to the Apache Software Foundation (ASF) under one
+#  or more contributor license agreements.  See the NOTICE file
+#  distributed with this work for additional information
+#  regarding copyright ownership.  The ASF licenses this file
+#  to you 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.
+###############################################################################
+
+
+SHELL := /bin/bash
+.SHELLFLAGS := -Eeuoc pipefail
+.ONESHELL:
+
+include Sharechat-Utils.mk
+
+build-docker-latest: \
+  require-var.GITHUB_USER require-var.GITHUB_TOKEN
+	docker build \
+		--tag "flink-kubernetes-operator:latest" \
+		--file ./Dockerfile \
+		.
+
+gcloud-auth-configure-docker:
+	gcloud auth configure-docker --quiet
+
+generate-docker-tag:
+	# We compute docker tag as following: we take git tag if it matches the pattern release-sharechat-*
+    # if suh tag exists, we remove release- prefix and use the rest as the docker tag. If such tag
+    # doesn't exist, we take last git commit hash instead.
+	rm -rf tmp-docker-tag.log
+	(git describe --tag --exact-match --match "release-sharechat-*" 2> /dev/null || git rev-parse HEAD) \
+		| sed 's/^release-//' >> tmp-docker-tag.log
+
+push-docker-gcr.%: build-docker-latest gcloud-auth-configure-docker generate-docker-tag \
+  require-var.DOCKER_REPO_%
+	dockerTag=$$(cat tmp-docker-tag.log)
+	dockerImage=${DOCKER_REPO_$(*)}/flink-kubernetes-operator:$${dockerTag}
+	docker tag flink-kubernetes-operator:latest $${dockerImage}
+	docker push $${dockerImage}
+	echo "Pushed Flink Kubernetes Operator image $$dockerImage"
+
+push-docker-gcr-all: push-docker-gcr.MOJ push-docker-gcr.SC

README.md

@@ -47,3 +47,15 @@ You can learn more about how to contribute in the [Apache Flink website](https:/
 ## License
 
 The code in this repository is licensed under the [Apache Software License 2](LICENSE).
+
+## ShareChat's fork
+
+We maintain our own fork of [Flink Kubernetes Operator](https://github.com/apache/flink-kubernetes-operator) according to the following rules:
+- ShareChat's main branch is main-sharechat
+- When proposing changes, we create branch from main-sharechat and make pull request with the base = main-sharechat
+- All pull request must have [ShareChat] prefix in the title so it gets passed to the corresponding commit in the main-sharechat branch
+- When new release of upstream Flink Kubernetes Operator is released, we create branch with the name release-sharechat-xxx starting from the corresponding release-xxx of the upstream operator
+- Once branch is created, we cherry-pick all the commits marked as [ShareChat] from main-sharechat
+- After that, we tag the last commit in the release branch by release-sharechat-xxx tag
+
+After that, to push the image to GCR, [this](https://teamcity.staging.sharechat.com/buildConfiguration/AiOrgProjects_FlinkKubernetesOperator_PushFlinkKubernetesOperatorImage?mode=builds) TeamCity build config should be used. 

Sharechat-Utils.mk

@@ -0,0 +1,29 @@
+###############################################################################
+#  Licensed to the Apache Software Foundation (ASF) under one
+#  or more contributor license agreements.  See the NOTICE file
+#  distributed with this work for additional information
+#  regarding copyright ownership.  The ASF licenses this file
+#  to you 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.
+###############################################################################
+
+
+define check_var
+	if [ -z "$($(1))" ]; then \
+    	echo "Environment variable $(1) is not set"; \
+    	exit 1; \
+    fi
+endef
+
+require-var.%:
+	@ $(call check_var,$(*))
+