Facility for cross-building RocksJava using Docker

Summary:
As an alternative to Vagrant, we can now also use Docker to cross-build RocksDB. The advantages are:

1. The Docker images are fixed; they include all the latest updates and build tools.
2. The Vagrant image, required scripts that ran for every build that would update CentOS and install the buildtools. This lead to slow repeatable builds, we don't need to do this with Docker as they are already in the provided images.

The Docker images I have used have their Docker build files here: https://github.com/evolvedbinary/docker-rocksjava and the images themselves are available from Docker hub: https://hub.docker.com/r/evolvedbinary/rocksjava/

I have added the following targets to the `Makefile`:
1. `rocksdbjavastaticreleasedocker` this uses Docker to perform the cross-builds. It is basically the Docker version of the existing Vagrant `rocksdbjavastaticrelease` target.
2. `rocksdbjavastaticpublishdocker` delegates to `rocksdbjavastaticreleasedocker` and then `rocksdbjavastaticpublishcentral` to upload the artiacts to Maven Central. Equivalent to the existing Vagrant target: `rocksdbjavastaticpublish`
Closes https://github.com/facebook/rocksdb/pull/2278

Differential Revision: D5048206

Pulled By: yiwu-arbug

fbshipit-source-id: 78fa96ef9d966fe09638ed01de282cd4e31961a9

Makefile

@@ -1576,8 +1576,25 @@ rocksdbjavastaticrelease: rocksdbjavastatic
 	cd java/target;jar -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
 	cd java/target/classes;jar -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
 
+rocksdbjavastaticreleasedocker: rocksdbjavastatic
+	DOCKER_LINUX_X64_CONTAINER=`docker ps -aqf name=rocksdb_linux_x64-be`; \
+	if [ -z "$$DOCKER_LINUX_X64_CONTAINER" ]; then \
+		docker container create --attach stdin --attach stdout --attach stderr --volume `pwd`:/rocksdb-host --name rocksdb_linux_x64-be evolvedbinary/rocksjava:centos5_x64-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh; \
+	fi
+	docker start -a rocksdb_linux_x64-be
+	DOCKER_LINUX_X86_CONTAINER=`docker ps -aqf name=rocksdb_linux_x86-be`; \
+	if [ -z "$$DOCKER_LINUX_X86_CONTAINER" ]; then \
+		docker container create --attach stdin --attach stdout --attach stderr --volume `pwd`:/rocksdb-host --name rocksdb_linux_x86-be evolvedbinary/rocksjava:centos5_x86-be /rocksdb-host/java/crossbuild/docker-build-linux-centos.sh; \
+	fi
+	docker start -a rocksdb_linux_x86-be
+	cd java;jar -cf target/$(ROCKSDB_JAR_ALL) HISTORY*.md
+	cd java/target;jar -uf $(ROCKSDB_JAR_ALL) librocksdbjni-*.so librocksdbjni-*.jnilib
+	cd java/target/classes;jar -uf ../$(ROCKSDB_JAR_ALL) org/rocksdb/*.class org/rocksdb/util/*.class
+
 rocksdbjavastaticpublish: rocksdbjavastaticrelease rocksdbjavastaticpublishcentral
 
+rocksdbjavastaticpublishdocker: rocksdbjavastaticreleasedocker rocksdbjavastaticpublishcentral
+
 rocksdbjavastaticpublishcentral:
 	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/rocksjni.pom -Dfile=java/target/rocksdbjni-$(ROCKSDB_MAJOR).$(ROCKSDB_MINOR).$(ROCKSDB_PATCH)-javadoc.jar -Dclassifier=javadoc
 	mvn gpg:sign-and-deploy-file -Durl=https://oss.sonatype.org/service/local/staging/deploy/maven2/ -DrepositoryId=sonatype-nexus-staging -DpomFile=java/rocksjni.pom -Dfile=java/target/rocksdbjni-$(ROCKSDB_MAJOR).$(ROCKSDB_MINOR).$(ROCKSDB_PATCH)-sources.jar -Dclassifier=sources

java/crossbuild/docker-build-linux-centos.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+set -e
+
+rm -rf /rocksdb-local
+cp -r /rocksdb-host /rocksdb-local
+cd /rocksdb-local
+scl enable devtoolset-2 'make jclean clean'
+scl enable devtoolset-2 'PORTABLE=1 make rocksdbjavastatic'
+cp java/target/librocksdbjni-linux*.so java/target/rocksdbjni-*-linux*.jar /rocksdb-host/java/target
+