50171283-externalise-jre-configuration to master

[Completes #50171283]

Author: nebhale

Gemfile.lock

@@ -2,9 +2,9 @@ GEM
   remote: https://rubygems.org/
   specs:
     diff-lcs (1.2.4)
-    multi_json (1.7.3)
+    multi_json (1.7.4)
     rake (10.0.4)
-    redcarpet (2.2.2)
+    redcarpet (2.3.0)
     rspec (2.13.0)
       rspec-core (~> 2.13.0)
       rspec-expectations (~> 2.13.0)

README.md

@@ -7,34 +7,76 @@
 
 [cf]: http://www.cloudfoundry.com
 
-
-# Configuration
-The buildpack allows you to configure the both the vendor and version of the Java runtime your application should use.  To configure these, you can either put a `system.properties` file into your pushed artifact, or specify environment variables for your application.  By default the **OpenJDK 7** Java runtime is chosen.
+# Buildpack Users
+The buildpack allows you to configure the both the vendor and version of the Java runtime your application should use.  To configure these, you can put a `system.properties` file into your pushed artifact.
 
 ## `system.properties`
 If a `system.properties` file exists anywhere within your artifact's filesystem and the following properties have been set, they will be read and used to select the Java runtime for your application:
 
-| Name |  Description
+| Name | Description
 | ---- | -----------
-| `java.runtime.vendor` | The vendor of the Java runtime to use.  Legal values are `oracle` or `openjdk`.
-| `java.runtime.version` | The version of the Java runtime to use.  The legal values are dependent on the vendor, but are typically `6`, `7`, `8`, `1.6`, `1.7`, and `1.8` are acceptable.
+| `java.runtime.vendor` | The vendor of the Java runtime to use.  The legal values are defined by the keys in [`config/jres.yml`][jres_yml].
+| `java.runtime.version` | The version of the Java runtime to use.  The legal values are defined by the keys in [`index.yml`][index_yml]
 
 An example `system.properties` file would to contain the following:
 ```java
 java.runtime.vendor=openjdk
-java.runtime.version=8
+java.runtime.version=1.7.0_21
 ```
+## JRE Version Syntax and Ordering
+JREs versions are composed of major, minor, micro, and optional qualifier parts (`<major>.<minor>.<micro>[_<qualifier>]`).  The major, minor, and micro parts must be numeric.  The qualifier part is composed of letters, digits, and hyphens.  The lexical ordering of the qualifier is:
 
-## Environment Variables
-If the following environment variables have been set, they will be read and used to select the Java runtime for your application:
+1. hyphen
+2. lowercase letters
+3. uppercase letters
+4. digits
 
-| Name |  Description
-| ---- | -----------
-| `JAVA_RUNTIME_VENDOR` | The vendor of the Java runtime to use.  Legal values are `oracle` or `openjdk`.
-| `JAVA_RUNTIME_VERSION` | The version of the Java runtime to use.  The legal values are dependent on the vendor, but are typically `6`, `7`, `8`, `1.6`, `1.7`, and `1.8` are acceptable.
+## JRE Version Wildcards
+In addition to declaring a specific version of JRE to use, you can also specify a bounded range of JRES to use.  Appending the `+` symbol to a version prefix chooses the latest JRE that begins with the prefix.
+
+| Example | Description
+| ------- | -----------
+| `1.+`   	| Selects the greatest available version less than `2.0.0`.
+| `1.7.+` 	| Selects the greatest available version less than `1.8.0`.
+| `1.7.0_+` | Selects the greatest available version less than `1.7.1`. Use this syntax to stay up to date with the latest security releases in a particular version.
+
+## Default JRE
+If the user does not specify a JRE vendor and version, a JRE is selected automatically.  The selection algorithm is as follows:
+
+1. If a single vendor is available, it is selected.  If zero or more than one vendor is available, the buildpack will fail.
+2. The latest version of JRE for the selected vendor is chosen.
+
+[jres_yml]: config/jres.yml
+[index_yml]: http://jres.gopivotal.com.s3.amazonaws.com/lucid/x86_64/openjdk/index.yml
+
+
+# Buildpack Developers
+This buildpacks is designed to be extensible by other developers.  To this end, various bits of configuration are exposed that make it simple to add functionality.
+
+## Adding JRES
+By default, this buildpack only allows users to choose from [OpenJDK][openjdk] JREs.  To allow users to choose a JRE from other vendors, these vendors must be specified in [`config/jres.yml`][jres_yml].  The file is [YAML][yaml] formatted with the following syntax:
 
-To set these properties for your application, do the following:
 ```plain
-cf set-env my-app JAVA_RUNTIME_VENDOR openjdk
-cf set-env my-app JAVA_RUNTIME_VERSION 8
+<vendor name>: <JRE repository root URI>
 ```
+
+The JRE repository root must contain a `/index.yml` file ([example][index_yml]).  This file is also [YAML][yaml] formatted with the following syntax:
+
+```plain
+<JRE version>: <path relative to JRE repository root>
+```
+
+The JRES uploaded to the repository must be gzipped TAR files and have no top-level directory ([example][example_jre]).
+
+An example filesystem might look like:
+
+```plain
+/index.yml
+/openjdk-1.6.0_27.tar.gz
+/openjdk-1.7.0_21.tar.gz
+/openjdk-1.8.0_M7.tar.gz
+```
+
+[openjdk]: http://openjdk.java.net
+[yaml]: http://www.yaml.org
+[example_jre]: http://jres.gopivotal.com.s3.amazonaws.com/lucid/x86_64/openjdk/openjdk-1.8.0_M7.tar.gz

config/jres.yml

@@ -0,0 +1,18 @@
+# Cloud Foundry Java Buildpack
+# Copyright (c) 2013 the original author or authors.
+#
+# Licensed 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.
+
+# Configuration for JRE repositories keyed by vendor
+---
+openjdk: "http://jres.gopivotal.com.s3.amazonaws.com/lucid/x86_64/openjdk"

lib/java_buildpack/compile.rb

@@ -14,10 +14,9 @@
 # limitations under the License.
 
 require 'java_buildpack/jre_properties'
-require 'java_buildpack/jre_selector'
 require 'java_buildpack/utils/format_duration'
-require 'java_buildpack/utils/os'
 require 'open-uri'
+require 'tempfile'
 
 module JavaBuildpack
 
@@ -31,9 +30,8 @@ class Compile
     # @param [String] app_cache_dir The application cache directory used during compilation
     def initialize(app_dir, app_cache_dir)
       @app_dir = app_dir
+      @app_cache_dir = app_cache_dir
       @jre_properties = JreProperties.new(app_dir)
-      jre_selector = JreSelector.new
-      @uri = jre_selector.uri(@jre_properties.vendor, @jre_properties.version)
     end
 
     # The execution entry point for detection.  This method is responsible for identifying all of the components that are
@@ -42,11 +40,21 @@ def initialize(app_dir, app_cache_dir)
     # @return [void]
     def run
       download_start_time = Time.now
-      print "-----> Downloading #{@jre_properties.vendor} #{@jre_properties.version} JRE from #{@uri} "
+      print "-----> Downloading #{@jre_properties.vendor} #{@jre_properties.version} JRE from #{@jre_properties.uri} "
+
+      file = Tempfile.new('jre', @app_cache_dir)
+      begin
+        open(@jre_properties.uri) do |stream|
+          IO.copy_stream(stream, file)
+          puts "(#{(Time.now - download_start_time).duration})"
+        end
+
+        file.close
 
-      open(@uri) do |file| # Use a global cache when available
-        puts "(#{(Time.now - download_start_time).duration})"
         expand file
+      ensure
+        file.close
+        file.unlink
       end
     end
 
@@ -59,26 +67,15 @@ def expand(file)
       print "-----> Expanding JRE to #{JAVA_HOME} "
 
       java_home = File.join @app_dir, JAVA_HOME
-      `rm -rf #{java_home}`
-      `mkdir -p #{java_home}`
-
-      expand_tar file, java_home
+      system "rm -rf #{java_home}"
+      system "mkdir -p #{java_home}"
+      system "tar xzf #{file.path} -C #{java_home} --strip 1 2>&1"
 
       puts "(#{(Time.now - expand_start_time).duration})"
     end
 
     def expand_tar(file, java_home)
-      `tar xzf #{file.path} -C #{java_home} --strip 1 2>&1`
-    end
-
-    def expand_deb(file, java_home)
-      if OS.linux?
-        filter = '--wildcards "./usr/lib/jvm/java-*/*"'
-      else
-        filter = '"./usr/lib/jvm/java-*/*"'
-      end
 
-      `tar xzOf #{file.path} data.tar.gz | tar xz -C #{java_home} --strip 5 #{filter} 2>&1`
     end
 
   end

lib/java_buildpack/detect.rb

@@ -14,7 +14,6 @@
 # limitations under the License.
 
 require 'java_buildpack/jre_properties'
-require 'java_buildpack/jre_selector'
 
 module JavaBuildpack
 
@@ -26,8 +25,6 @@ class Detect
     # @param [String] app_dir The application directory used during detection
     def initialize(app_dir)
       @jre_properties = JreProperties.new(app_dir)
-      # Diagnose invalid vendor or version.
-      JreSelector.new.uri(@jre_properties.vendor, @jre_properties.version)
     end
 
     # The execution entry point for detection.  This method is responsible for identifying all of the components that are

lib/java_buildpack/jre_properties.rb

@@ -13,75 +13,57 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-require 'java_buildpack/utils/properties'
+
+require 'java_buildpack/utils/value_resolver'
+require 'java_buildpack/vendor_resolver'
+require 'java_buildpack/version_resolver'
+require 'open-uri'
+require 'yaml'
+
 
 module JavaBuildpack
 
   # A class encapsulating the JRE properties specified by the user.
   class JreProperties
 
-    DEFAULT_VENDOR = 'openjdk'
-
     # @!attribute [r] vendor
-    #   @return [String] the JRE vendor requested by the user
+    #   @return [String] the resolved JRE vendor based on user input
     # @!attribute [r] version
-    #   @return [String] the JRE version requested by the user
-    attr_reader :vendor, :version
+    #   @return [String] the resolved JRE version based on user input
+    # @!attribute [r] uri
+    #   @return [String] the resolved JRE URI based on user input
+    attr_reader :vendor, :version, :uri
 
     # Creates a new instance, passing in the application directory used during release
     #
     # @param [String] app_dir The application to inspect for values specified by the user
     def initialize(app_dir)
-      properties = system_properties(app_dir)
+      value_resolver = ValueResolver.new(app_dir)
 
-      @vendor = configured_vendor properties
-      @vendor = DEFAULT_VENDOR if @vendor.nil?
+      candidate_vendor = value_resolver.resolve(ENV_VAR_VENDOR, SYS_PROP_VENDOR)
+      candidate_version = value_resolver.resolve(ENV_VAR_VERSION, SYS_PROP_VERSION)
 
-      @version = configured_version properties
+      jre_vendor_repositories = YAML.load_file JRES_YAML_FILE
+      @vendor = VendorResolver.resolve(candidate_vendor, jre_vendor_repositories.keys)
+      repository = jre_vendor_repositories[@vendor]
+      index = YAML.parse(open "#{repository}#{INDEX_PATH}").to_ruby
+      @version = VersionResolver.resolve(candidate_version, index.keys)
+      @uri = "#{repository}/#{index[@version]}"
     end
 
     private
 
-    SYSTEM_PROPERTIES = 'system.properties'
-
     ENV_VAR_VENDOR = 'JAVA_RUNTIME_VENDOR'
 
-    PROP_KEY_VENDOR = 'java.runtime.vendor'
-
     ENV_VAR_VERSION = 'JAVA_RUNTIME_VERSION'
 
-    PROP_KEY_VERSION = 'java.runtime.version'
+    INDEX_PATH = '/index.yml'
 
-    def system_properties(app_dir)
-      candidates = Dir["#{app_dir}/**/#{SYSTEM_PROPERTIES}"]
+    JRES_YAML_FILE = 'config/jres.yml'
 
-      if candidates.length > 1
-        raise "More than one system.properties file found: #{candidates}"
-      end
+    SYS_PROP_VENDOR = 'java.runtime.vendor'
 
-      if candidates[0]
-        Properties.new(candidates[0])
-      else
-        nil
-      end
-    end
+    SYS_PROP_VERSION = 'java.runtime.version'
 
-    def configured_vendor(properties)
-      resolve ENV_VAR_VENDOR, PROP_KEY_VENDOR, properties
-    end
-
-    def configured_version(properties)
-      resolve ENV_VAR_VERSION, PROP_KEY_VERSION, properties
-    end
-
-    def resolve(env_var, prop_key, properties, default = nil)
-      value = ENV[env_var]
-
-      if value.nil? && !properties.nil?
-        value = properties[prop_key]
-      end
-
-      value
-    end
   end
 end

lib/java_buildpack/jre_selector.rb

@@ -14,8 +14,6 @@
 # limitations under the License.
 
 require 'java_buildpack/jre_properties'
-require 'java_buildpack/jre_selector'
-require 'java_buildpack/utils/properties'
 require 'yaml'
 
 module JavaBuildpack
@@ -29,9 +27,7 @@ class Release
     def initialize(app_dir)
       @app_dir = app_dir
 
-      # Diagnose invalid vendor or version.
-      jre_properties = JreProperties.new(app_dir)
-      JreSelector.new.uri(jre_properties.vendor, jre_properties.version)
+      JreProperties.new(app_dir)
     end
 
     # The execution entry point for release.  This method is responsible for generating a payload describing the execution