翻译：https://cwiki.apache.org/confluence/display/AMBARI/Defining+a+Custom+Service

自定义服务包含以下步骤：

1 创建服务文件夹

2 创建描述服务信息的Metainfo.xml

3 创建关于安装、配置、启动、停止等命令的脚本

4 给自定义服务添加配置

 

自定义服务定义完成以后重启server就能在添加服务中找到自定义服务

命令：ambari-server restart

实现自定义服务例子

在本例子中创建一个服务SAMPLESRV，包括三个组件MASTER, SLAVE 和CLIENT。

1 创建服务

在/ambari/ambari-server/src/main/resources/stacks/HDP/2.5/services/目录下创建SAMPLESRV目录

mkdir SAMPLESRV

cd SAMPLESRV

 

注意：文件夹名字不能和Ambari预定义的相同，比如HUE


2 在SAMPLESRV目录中创建metainfo.xml文件

内容如下

<?xml version="1.0"?>
<metainfo>
    <schemaVersion>2.0</schemaVersion>
    <services>
        <service>
            <name>SAMPLESRV</name>
            <displayName>New Sample Service</displayName>
            <comment>A New Sample Service</comment>
            <version>1.0.0</version>
            <components>
                <component>
                    <name>SAMPLESRV_MASTER</name>
                    <displayName>Sample Srv Master</displayName>
                    <category>MASTER</category>
                    <cardinality>1</cardinality>
                    <commandScript>
                        <script>scripts/master.py</script>
                        <scriptType>PYTHON</scriptType>
                        <timeout>600</timeout>
                    </commandScript>
                </component>
                <component>
                    <name>SAMPLESRV_SLAVE</name>
                    <displayName>Sample Srv Slave</displayName>
                    <category>SLAVE</category>
                    <cardinality>1+</cardinality>
                    <commandScript>
                        <script>scripts/slave.py</script>
                        <scriptType>PYTHON</scriptType>
                        <timeout>600</timeout>
                    </commandScript>
                </component>
                <component>
                    <name>SAMPLESRV_CLIENT</name>
                    <displayName>Sample Srv Client</displayName>
                    <category>CLIENT</category>
                    <cardinality>1+</cardinality>
                    <commandScript>
                        <script>scripts/sample_client.py</script>
                        <scriptType>PYTHON</scriptType>
                        <timeout>600</timeout>
                    </commandScript>
                </component>
            </components>
            <osSpecifics>
                <osSpecific>
                    <osFamily>any</osFamily>
                </osSpecific>
            </osSpecifics>
        </service>
    </services>
</metainfo>

服务的metainfo.xml文件描述了服务信息，组件信息和执行命令的脚本。服务的组件有三种类型：MASTER，SLAVE和CLIENT。下表展示了每种类型必须支持的命令，也可以自己拓展命令。



  

组件类型


  


  

默认的生命周期命令


 

MASTER


 


 

install, start, stop, configure, status


 


 

SLAVE


 


 

install, start, stop, configure, status


 


 

CLIENT


 


 

install, configure, status


 


 

 

SAMPLESRV_MASTER是MASTER类型的组件，命令的实现方法所在脚本是services/SAMPLESRV/package /scripts/master.py。

脚本是PYTHON编写的，实现了默认的生命周期命令。

 

在metainfo中有一个选项设置configuration-dir，缺省默认值是configuration

也可以自己制定配置文件的存放位置

<configuration-dir>configuration</configuration-dir>

在configuration-dependencies部分设置配置依赖关系，可以针对服务全体或者组件部分设置添加。依赖的含义在于当config-type更新后ambari自动重启相关的组件和服务。

<configuration-dependencies>
  <config-type>core-site</config-type>
  <config-type>hdfs-site</config-type>
</configuration-dependencies>

3 下一步创建命令脚本

1）创建目录SAMPLESRV/package/scripts 

mkdir -p package/scripts

cd package/scripts

2）在scripts目录下创建命令脚本

  1. master.py内容：
import sys
from resource_management import *
class Master(Script):
  def install(self, env):
    print 'Install the Sample Srv Master';
  def configure(self, env):
    print 'Configure the Sample Srv Master';
  def stop(self, env):
    print 'Stop the Sample Srv Master';
  def start(self, env):
    print 'Start the Sample Srv Master';
  def status(self, env):
    print 'Status of the Sample Srv Master';
if __name__ == "__main__":
  Master().execute()

 

 2 .slave.py内容

import sys
from resource_management import *
class Slave(Script):
  def install(self, env):
    print 'Install the Sample Srv Slave';
  def configure(self, env):
    print 'Configure the Sample Srv Slave';
  def stop(self, env):
    print 'Stop the Sample Srv Slave';
  def start(self, env):
    print 'Start the Sample Srv Slave';
  def status(self, env):
    print 'Status of the Sample Srv Slave';
if __name__ == "__main__":
  Slave().execute()

 

3.sample_client.py 内容

import sys
from resource_management import *
class SampleClient(Script):
  def install(self, env):
    print 'Install the Sample Srv Client';
  def configure(self, env):
    print 'Configure the Sample Srv Client';
if __name__ == "__main__":
  SampleClient().execute()

 

 

在metainfo.xml的client组件中添加自定义命令SOMETHINGCUSTOM

<component>
    <name>SAMPLESRV_CLIENT</name>
    <displayName>Sample Srv Client</displayName>
    <category>CLIENT</category>
    <cardinality>1+</cardinality>
    <commandScript>
        <script>scripts/sample_client.py</script>
        <scriptType>PYTHON</scriptType>
        <timeout>600</timeout>
    </commandScript>
    <customCommands>
      <customCommand>
        <name>SOMETHINGCUSTOM</name>
        <commandScript>
          <script>scripts/sample_client.py</script>
          <scriptType>PYTHON</scriptType>
          <timeout>600</timeout>
        </commandScript>
      </customCommand>
    </customCommands>
</component>

 

在package/scripts/sample_client.py中添加命令对应的处理方法

import sys
from resource_management import *
 
class SampleClient(Script):
  def install(self, env):
    print 'Install the Sample Srv Client';
  def configure(self, env):
    print 'Configure the Sample Srv Client';
  def somethingcustom(self, env):
    print 'Something custom';
 
if __name__ == "__main__":
  SampleClient().execute()

 

 

4 给自定义服务添加配置

在下面的例子中添加配置类型test-config

1)修改metainfo.xml

<component>
    <name>SAMPLESRV_CLIENT</name>
    <displayName>Sample Srv Client</displayName>
    <category>CLIENT</category>
    <cardinality>1+</cardinality>
    <commandScript>
        <script>scripts/sample_client.py</script>
        <scriptType>PYTHON</scriptType>
        <timeout>600</timeout>
    </commandScript>
    <configFiles>
      <configFile>
        <type>xml</type>
        <fileName>test-config.xml</fileName>
        <dictionaryName>test-config</dictionaryName>
      </configFile>
    </configFiles>
</component>
2 )创建配置目录SAMPLESRV/configuration
mkdir -p configuration
cd configuration

3) 创建test-config.xml 

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
 
<configuration>
  <property>
    <name>some.test.property</name>
    <value>this.is.the.default.value</value>
    <description>This is a test description.</description>
  </property>
  <property>
    <name>another.test.property</name>
    <value>5</value>
    <description>This is a second test description.</description>
  </property>
</configuration>