Added less hacky way of downloading jars

Makefile

@@ -2,52 +2,52 @@ include golang.mk
 .DEFAULT_GOAL := test # override default goal set in library makefile
 
 SHELL := /bin/bash
-JAR_DIR := jars
 PKG := github.com/Clever/amazon-kinesis-client-go
 PKGS := $(shell go list ./... | grep -v /vendor )
 .PHONY: download_jars run build
-
-URL_PREFIX := http://search.maven.org/remotecontent?filepath=
-
-# this list lifted from https://github.com/awslabs/amazon-kinesis-client-python/blob/fb49c6390c0593fbcf81d6c34c5245726c15b2f3/setup.py#L60
-JARS_TO_DOWNLOAD := $(addprefix $(JAR_DIR)/,com/amazonaws/amazon-kinesis-client/1.7.2/amazon-kinesis-client-1.7.2.jar \
-com/amazonaws/aws-java-sdk-dynamodb/1.11.14/aws-java-sdk-dynamodb-1.11.14.jar \
-com/amazonaws/aws-java-sdk-s3/1.11.14/aws-java-sdk-s3-1.11.14.jar \
-com/amazonaws/aws-java-sdk-kms/1.11.14/aws-java-sdk-kms-1.11.14.jar \
-com/amazonaws/aws-java-sdk-core/1.11.14/aws-java-sdk-core-1.11.14.jar \
-commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar \
-org/apache/httpcomponents/httpclient/4.5.2/httpclient-4.5.2.jar \
-org/apache/httpcomponents/httpcore/4.4.4/httpcore-4.4.4.jar \
-commons-codec/commons-codec/1.9/commons-codec-1.9.jar \
-com/fasterxml/jackson/core/jackson-databind/2.6.6/jackson-databind-2.6.6.jar \
-com/fasterxml/jackson/core/jackson-annotations/2.6.0/jackson-annotations-2.6.0.jar \
-com/fasterxml/jackson/core/jackson-core/2.6.6/jackson-core-2.6.6.jar \
-com/fasterxml/jackson/dataformat/jackson-dataformat-cbor/2.6.6/jackson-dataformat-cbor-2.6.6.jar \
-joda-time/joda-time/2.8.1/joda-time-2.8.1.jar \
-com/amazonaws/aws-java-sdk-kinesis/1.11.14/aws-java-sdk-kinesis-1.11.14.jar \
-com/amazonaws/aws-java-sdk-cloudwatch/1.11.14/aws-java-sdk-cloudwatch-1.11.14.jar \
-com/google/guava/guava/18.0/guava-18.0.jar \
-com/google/protobuf/protobuf-java/2.6.1/protobuf-java-2.6.1.jar \
-commons-lang/commons-lang/2.6/commons-lang-2.6.jar)
-
-EMPTY :=
-SPACE := $(EMPTY) $(EMPTY)
-JAVA_CLASS_PATH := $(subst $(SPACE),:,$(JARS_TO_DOWNLOAD))
+$(eval $(call golang-version-check,1.8))
 
 CONSUMER ?= consumer
+TMP_DIR := ./tmp-jars
+JAR_DIR := ./jars/
+KCL_VERSION := 1.7.6
 
-$(JARS_TO_DOWNLOAD):
-	mkdir -p `dirname $@`
-	curl -s -L -o $@ -O $(URL_PREFIX)`echo $@ | sed 's/$(JAR_DIR)\///g'`
+define POM_XML_FOR_GETTING_DEPENDENT_JARS
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.clever.kinesisconsumers</groupId>
+  <artifactId>$(CONSUMER)</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <dependencies>
+    <dependency>
+      <groupId>com.amazonaws</groupId>
+      <artifactId>amazon-kinesis-client</artifactId>
+      <version>$(KCL_VERSION)</version>
+    </dependency>
+  </dependencies>
+</project>
+endef
+export POM_XML_FOR_GETTING_DEPENDENT_JARS
+download_jars:
+	command -v mvn >/dev/null 2>&1 || { echo >&2 "Maven not installed. Install maven!"; exit 1; }
+	mkdir -p $(JAR_DIR) $(TMP_DIR)
+	echo $$POM_XML_FOR_GETTING_DEPENDENT_JARS > $(TMP_DIR)/pom.xml
+	cd $(TMP_DIR) && mvn dependency:copy-dependencies
+	mv $(TMP_DIR)/target/dependency/* $(JAR_DIR)/
+	# Download the STS jar file for supporting IAM Roles
+	ls $(JAR_DIR)/aws-java-sdk-core-*.jar | sed -e "s/.*-sdk-core-//g" | sed -e "s/\.jar//g" > /tmp/version.txt
+	curl -o $(JAR_DIR)/aws-java-sdk-sts-`cat /tmp/version.txt`.jar http://central.maven.org/maven2/com/amazonaws/aws-java-sdk-sts/`cat /tmp/version.txt`/aws-java-sdk-sts-`cat /tmp/version.txt`.jar
+	rm -r $(TMP_DIR)
 
-download_jars: $(JARS_TO_DOWNLOAD)
+all: test build
 
 build:
 	CGO_ENABLED=0 go build -installsuffix cgo -o build/$(CONSUMER) $(PKG)/cmd/$(CONSUMER)
 
 run: build download_jars
 	command -v java >/dev/null 2>&1 || { echo >&2 "Java not installed. Install java!"; exit 1; }
-	java -cp $(JAVA_CLASS_PATH) \
+	java -cp "$(JAR_DIR)/*" \
 	com.amazonaws.services.kinesis.multilang.MultiLangDaemon \
 	$(CONSUMER).properties