Include a pre-built protoc in `pulsar-build` docker image (#743)

build/docker/Dockerfile

@@ -19,6 +19,10 @@
 
 FROM ubuntu:16.04
 
+# prepare the directory for pulsar related files
+RUN mkdir /pulsar
+ADD protobuf.patch /pulsar
+
 RUN apt-get update
 RUN apt-get install -y maven tig g++ cmake libssl-dev libcurl4-openssl-dev \
                 liblog4cxx-dev libprotobuf-dev libboost-all-dev  libgtest-dev \
@@ -51,3 +55,12 @@ RUN wget https://github.com/pseudomuto/protoc-gen-doc/releases/download/v1.0.0-a
     tar xvfz protoc-gen-doc-1.0.0-alpha.linux-amd64.go1.8.1.tar.gz && \
     cp protoc-gen-doc-1.0.0-alpha.linux-amd64.go1.8.1/protoc-gen-doc /usr/local/bin && \
     rm protoc-gen-doc-1.0.0-alpha.linux-amd64.go1.8.1.tar.gz
+
+# Build the patched protoc
+RUN git clone https://github.com/google/protobuf.git /pulsar/protobuf && \
+    cd /pulsar/protobuf && \
+    git checkout v2.4.1 && \
+    patch -p1 < /pulsar/protobuf.patch && \
+    autoreconf --install && \
+    ./configure && \
+    make

protobuf/README.md

@@ -11,15 +11,9 @@ The pre-generated Java code is at `pulsar-common/src/main/java/org/apache/pulsar
 
 We are currently using a modified version of the Google Protocol Buffer code generator, to generate code that can serialize/deserialize messages with no memory allocations (caching already instantiated objects) and also to be able to directly use Netty pooled ByteBuf with direct memory.
 
-To re-generate the `PulsarApi.java` code you need to apply a patch to the protobuf generator. Patch is found in `protobuf.patch`.
+To re-generate the `PulsarApi.java` code you need to apply a patch to the protobuf generator. Patch is found in `build/docker/protobuf.patch`.
 
-### For C++ Client:
-
-The pre-generated C++ code is at `pulsar-client-cpp/lib/PulsarApi.pb.cc` and `pulsar-client-cpp/lib/PulsarApi.pb.h`.
-
-You don't need to manually generate C++ code. The C++ code is automatically generated by `cmake`.
-
-### Commands for creating the pre-generated Java code
+#### Commands for creating the pre-generated Java code
 
 ```shell
 export PULSAR_HOME=<Path where you cloned the pulsar repo>
@@ -31,7 +25,7 @@ cd ${HOME}/protobuf
 git checkout v2.4.1
 
 ### Apply patch
-patch -p1 < ${PULSAR_HOME}/protobuf/protobuf.patch
+patch -p1 < ${PULSAR_HOME}/build/docker/protobuf.patch
 
 ### Compile protobuf
 autoreconf --install
@@ -43,3 +37,16 @@ cd ${PULSAR_HOME}/pulsar-common/
 export PROTOC=${HOME}/protobuf/src/protoc 
 ./generate_protobuf.sh
 ```
+
+Or you can use the pre-built protoc included in `pulsar-build` docker image to generate java protobuf files.
+
+```
+cd ${PULSAR_HOME}/pulsar-common/
+./generate_protobuf_docker.sh
+```
+
+### For C++ Client:
+
+The pre-generated C++ code is at `pulsar-client-cpp/lib/PulsarApi.pb.cc` and `pulsar-client-cpp/lib/PulsarApi.pb.h`.
+
+You don't need to manually generate C++ code. The C++ code is automatically generated by `cmake`.

pulsar-common/generate_protobuf_docker.sh

+#!/bin/bash
+#
+# 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.
+#
+
+# Fail script in case of errors
+set -e
+
+ROOT_DIR=$(git rev-parse --show-toplevel)
+COMMON_DIR=$ROOT_DIR/pulsar-common
+cd $COMMON_DIR
+
+BUILD_IMAGE_NAME="${BUILD_IMAGE_NAME:-apachepulsar/pulsar-build}"
+BUILD_IMAGE_VERSION="${BUILD_IMAGE_VERSION:-ubuntu-16.04}"
+
+IMAGE="$BUILD_IMAGE_NAME:$BUILD_IMAGE_VERSION"
+
+echo $IMAGE
+
+docker run -i \
+    -v ${COMMON_DIR}:${COMMON_DIR} $IMAGE \
+    bash -c "cd ${COMMON_DIR}; /pulsar/protobuf/src/protoc --java_out=src/main/java src/main/proto/PulsarApi.proto"