【Elasticsearch 5.6.12 源码】——【1】源代码调试环境搭建

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简介

本文主要解决以下问题：

1、从何处以及如何下载Elasticsearch 5.6.12的源代码？
2、如何将源代码导入到IntelliJ IDEA中进行编辑？
3、如何在IDEA中运行并调试Elasticsearch的源代码？

软件环境

本文写作时在Windows 7系统上搭建了源代码调试环境，工作中使用相同的步骤在Fedora 24上搭建了开发环境。本文使用的软件环境如下：

• JDK 1.8.0_144
• Gradle 4.8.1
• IntelliJ IDEA 2017.2.7

源码下载

从elastic官方的GitHub仓库中去下载Elasticsearch 的源代码。你可以使用git clone的方式下载，也可以GitHub的下载链接单独下载ZIP文件。本文采用第二种方式，如下图所示：

导入IDEA

Elasticsearch 5.X 使用Gradle包装器进行构建，在将源码导入IDEA前可以使用gradlew执行源码中提供的脚本自动生成IDEA需要的配置文件。

1、构建源码

将下载完的源码文件解压，在源码文件的根目录执行如下命令：

gradlew idea

因为需要下载相关依赖，执行的时间可能会比较长。因为网络原因配置过程可能会执行失败，这样的情况多试几次即可。最终构建成功的界面如下图所示：

2、导入IDEA

在IDEA中选择File -> New -> Project From Existing Sources...在弹出的对话框中选择Elasticsearch 5.6.12源码的根目录，点击OK后在之后出现的对话框中选择Import project from external model -> Gradle，如下图所示：

点击下方的Next按钮，在接下来的对话框中选中Use auto-import并点击下方的Finish按钮后，IDEA及开始导入Elasticsearch的源码。导入成功后，如下图所示：

运行源代码

在源代码的根目录下新建debug-home目录，做调试源码时的配置及数据目录。将源码根目录下的distribution.src.main.resources.config目录及里边的内容拷贝到debug-home目录中，并在debug-home目录中创建如下图所示的目录：

在debug-home.config目录中增加debug-security.policy文件，并在文件内添加如下内容：

grant { // needed to generate runtime classes permission java.lang.RuntimePermission "createClassLoader"; // needed by IndyInterface permission java.lang.RuntimePermission "getClassLoader"; // needed by groovy engine permission java.lang.RuntimePermission "accessDeclaredMembers"; permission java.lang.RuntimePermission "accessClassInPackage.sun.reflect"; permission java.lang.RuntimePermission "accessClassInPackage.jdk.internal.reflect"; // Allow executing groovy scripts with codesource of /untrusted permission groovy.security.GroovyCodeSourcePermission "/untrusted"; // Standard set of classes permission org.elasticsearch.script.ClassPermission "<<STANDARD>>"; // groovy runtime (TODO: clean these up if possible) permission org.elasticsearch.script.ClassPermission "groovy.grape.GrabAnnotationTransformation"; permission org.elasticsearch.script.ClassPermission "groovy.lang.Binding"; permission org.elasticsearch.script.ClassPermission "groovy.lang.GroovyObject"; permission org.elasticsearch.script.ClassPermission "groovy.lang.GString"; permission org.elasticsearch.script.ClassPermission "groovy.lang.Script"; permission org.elasticsearch.script.ClassPermission "groovy.util.GroovyCollections"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.ast.builder.AstBuilderTransformation"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.reflection.ClassInfo"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.runtime.GStringImpl"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.runtime.powerassert.ValueRecorder"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.runtime.powerassert.AssertionRenderer"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.runtime.ScriptBytecodeAdapter"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.vmplugin.v7.IndyInterface"; permission org.elasticsearch.script.ClassPermission "sun.reflect.ConstructorAccessorImpl"; permission org.elasticsearch.script.ClassPermission "sun.reflect.MethodAccessorImpl"; permission org.elasticsearch.script.ClassPermission "jdk.internal.reflect.ConstructorAccessorImpl"; permission org.elasticsearch.script.ClassPermission "jdk.internal.reflect.MethodAccessorImpl"; permission org.elasticsearch.script.ClassPermission "groovy.lang.Closure"; permission org.elasticsearch.script.ClassPermission "org.codehaus.groovy.runtime.GeneratedClosure"; permission org.elasticsearch.script.ClassPermission "groovy.lang.MetaClass"; permission org.elasticsearch.script.ClassPermission "groovy.lang.Range"; permission org.elasticsearch.script.ClassPermission "groovy.lang.Reference"; permission java.lang.RuntimePermission "createClassLoader"; permission java.io.FilePermission "/proc/sys/net/core/somaxconn", "read"; permission java.util.PropertyPermission "sun.nio.ch.bugLevel", "write"; // needed to generate runtime classes permission java.lang.RuntimePermission "createClassLoader"; permission java.lang.RuntimePermission "accessClassInPackage.sun.misc"; // expression runtime permission org.elasticsearch.script.ClassPermission "java.lang.String"; permission org.elasticsearch.script.ClassPermission "org.apache.lucene.expressions.Expression"; permission org.elasticsearch.script.ClassPermission "org.apache.lucene.search.DoubleValues"; // available functions permission org.elasticsearch.script.ClassPermission "java.lang.Math"; permission org.elasticsearch.script.ClassPermission "org.apache.lucene.util.MathUtil"; permission org.elasticsearch.script.ClassPermission "org.apache.lucene.util.SloppyMath"; permission java.lang.reflect.ReflectPermission "suppressAccessChecks"; };

在debug-home.modules目录中增加transport-netty4目录，并在该目录中增加plugin-descriptor.properties文件，文件内容如下：

# Elasticsearch plugin descriptor file # This file must exist as 'plugin-descriptor.properties' in a folder named `elasticsearch` # inside all plugins. # ### example plugin for "foo" # # foo.zip <-- zip file for the plugin, with this structure: #|____elasticsearch/ #| |____ <arbitrary name1>.jar <-- classes, resources, dependencies #| |____ <arbitrary nameN>.jar <-- any number of jars #| |____ plugin-descriptor.properties <-- example contents below: # # classname=foo.bar.BazPlugin # description=My cool plugin # version=2.0 # elasticsearch.version=2.0 # java.version=1.7 # ### mandatory elements for all plugins: # # 'description': simple summary of the plugin description=Netty 4 based transport implementation # # 'version': plugin's version version=5.6.12 # # 'name': the plugin name name=transport-netty4 # # 'classname': the name of the class to load, fully-qualified. classname=org.elasticsearch.transport.Netty4Plugin # # 'java.version': version of java the code is built against # use the system property java.specification.version # version string must be a sequence of nonnegative decimal integers # separated by "."'s and may have leading zeros java.version=1.8 # # 'elasticsearch.version': version of elasticsearch compiled against elasticsearch.version=5.6.12 ### optional elements for plugins: # # 'has.native.controller': whether or not the plugin has a native controller has.native.controller=false 

在IDEA中选择Run -> Edit Configurations...，在弹出的对话框中按如下图填写：

其中VM options处填写的内容如下：

-Xms4096m -Xmx4096m -Dlog4j2.disable.jmx=true -Des.path.home=E:\idea_workspace\elasticsearch-5.6.12\debug-home -Des.path.conf=E:\idea_workspace\elasticsearch-5.6.12\debug-home\config -Djava.security.policy=E:\idea_workspace\elasticsearch-5.6.12\debug-home\config\debug-security.policy

修改core模块中的build.gradle文件，在其中依赖配置的末尾增加如下图所示的配置：

至此，通过IDEA中的Run -> Debug 'Elasticsearch'已经可以成功运行Elasticsearch的源码，但是该工程目前仅加载了transport-netty4这一个非核心模块。如下图所示：