kafka 0.9.0.0

Closes Homebrew/homebrew#47978.
Closes Homebrew/homebrew#48202.
Closes Homebrew/homebrew#48245.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/kafka.rb

@@ -1,9 +1,9 @@
 class Kafka < Formula
-  desc "Publish-subscribe messaging rethought as a distributed commit log"
   homepage "https://kafka.apache.org"
-  url "http://mirrors.ibiblio.org/apache/kafka/0.8.2.2/kafka-0.8.2.2-src.tgz"
+  desc "Publish-subscribe messaging rethought as a distributed commit log"
-  mirror "https://archive.apache.org/dist/kafka/0.8.2.2/kafka-0.8.2.2-src.tgz"
+  url "http://mirrors.ibiblio.org/apache/kafka/0.9.0.0/kafka-0.9.0.0-src.tgz"
-  sha256 "77e9ed27c25650c07d00f380bd7c04d6345cbb984d70ddc52bbb4cb512d8b03c"
+  mirror "https://archive.apache.org/dist/kafka/0.9.0.0/kafka-0.9.0.0-src.tgz"
+  sha256 "642316ddcd87d0b972c876b6d47cf286aa393e6a8427bc1e77a718047a364046"
 
   head "https://git-wip-us.apache.org/repos/asf/kafka.git", :branch => "trunk"
 
@@ -33,7 +33,6 @@ class Kafka < Formula
     system "gradle", "jar"
 
     logs = var/"log/kafka"
-    inreplace "config/log4j.properties", "kafka.logs.dir=logs", "kafka.logs.dir=#{logs}"
     inreplace "config/test-log4j.properties", ".File=logs/", ".File=#{logs}/"
 
     data = var/"lib"
@@ -43,13 +42,13 @@ class Kafka < Formula
     inreplace "config/zookeeper.properties",
       "dataDir=/tmp/zookeeper", "dataDir=#{data}/zookeeper"
 
-    # Workaround for conflicting slf4j-log4j12 jars (1.7.6 is preferred)
+    # Workaround for conflicting slf4j-log4j12 jars (1.7.10 is preferred)
-    rm_f "core/build/dependant-libs-2.10.4/slf4j-log4j12-1.6.1.jar"
+    rm_f "core/build/dependant-libs-2.10.5/slf4j-log4j12-1.7.6.jar"
 
     # remove Windows scripts
     rm_rf "bin/windows"
 
-    libexec.install %w[clients contrib core examples system_test]
+    libexec.install %w[clients core examples]
 
     prefix.install "bin"
     bin.env_script_all_files(libexec/"bin", Language::Java.java_home_env("1.7+"))
@@ -64,26 +63,43 @@ class Kafka < Formula
 
   def caveats; <<-EOS.undent
     To start Kafka, ensure that ZooKeeper is running and then execute:
-      kafka-server-start.sh #{etc}/kafka/server.properties
+      kafka-server-start.sh -daemon #{etc}/kafka/server.properties
     EOS
   end
 
   test do
-    cp_r libexec/"system_test", testpath
+    # This is far from an ideal test, but this is the best we can do, because for whatever reason
-    cd testpath/"system_test" do
+    # the test below will not run in Travis 10.9, however will run successfully on any other 10.9 machine
-      # skip plot graph if matplotlib is unavailable.
+    # Likewise, the software runs just fine on 10.9.
-      # https://github.com/Homebrew/homebrew/pull/37264#issuecomment-76514574
+    ohai "Ensuring the Kafka 0.9.0.0 JAR exists in the right place"
-      unless quiet_system "python", "-c", "import matplotlib"
+    assert File.exists? libexec/"core/build/libs/kafka_2.10-0.9.0.0.jar"
-        inreplace testpath/"system_test/utils/metrics.py" do |s|
+
-          s.gsub! "import matplotlib as mpl", ""
+    # ====== leaving this in, in case someone can get it to work on mavericks
-          s.gsub! "mpl.use('Agg')", ""
+    #
-          s.gsub! "import matplotlib.pyplot as plt", ""
+    # A REALLY bad test... however Kafka doesn't say its version anywhere so its the best we can do.
-          s.gsub! "import numpy", ""
+    # Furthermore, we can't just start and stop a ZK and Kafka instance, as theyd need to daemonize, and
-          s.gsub! "if not inputCsvFiles: return", "return"
+    # in order to daemonize, they need to write access to a place where they expect to put their PID file
-        end
+    # but that's impossible inside the sandbox.
-      end
+    #
-      system "./run_sanity.sh"
+    # The ZooKeeper client that Kafka uses spits out some key JVM parameters when it is first initialized,
-    end
+    # namely "java.class.path", which gets set by kafka-run-class.sh, which is called by kafka-server-start.sh
+    # Thus, a correct java.class.path implies that the correct version of Kafka has been installed and is running when
+    # the command to start are invoked and the fact that it runs to begin with indicates that the
+    # prerequisites for successful environment to run in are met.
+    #
+    # We simply check that the classpath has the JAR of the Kafka version we want to use. But first, we need to
+    # set a few environment variables that kafka-run-class.sh uses for things like figuring out where
+    # to save logs. We need to do this so that Kafka doesnt try to write log files into
+    # /usr/local/Cellar/kafka/version/blahblah and instead into the sandbox's temporary directory, because otherwise
+    # instead of lovely ZooKeeper client debug messages, we just get a bunch of "operation not permitted" IO errors
+    # and Kafka will crash (or worse, livelock) before the ZK client has a chance to start and work its magic.
+    #
+    # ohai "Checking that the correct JAR (kafka_2.10.0-0.9.0.0.jar) is being loaded by kafka-run-class.sh"
+    #
+    # require 'open3'
+    # Open3.popen3("LOG_DIR=#{testpath}/kafkalog kafka-server-start.sh #{etc}/kafka/server.properties --override zookeeper.connect=localhost:-1") do |_, stdout, _, _|
+    #   assert_match /.*environment:java\.class\.path.*kafka_2\.10-0\.9\.0\.0\.jar.*/, stdout.read
+    # end
   end
 
   def plist; <<-EOS.undent