oozie架构图

从oozie的架构图中，可以看到所有的任务都是通过oozie生成相应的任务客户端，并通过任务客户端来提交相应的任务；
对oozie的二次开发都集中在了oozie server那里，其实官网是有自定义例子：http://oozie.apache.org/docs/4.2.0/DG_CustomActionExecutor.html ，但如果了解oozie项目的代码架构有助于二次开发和调错，二次开发的步骤大概有三个步骤：
a.设计workflow流程且设计xsd schema文件
b.编写action的代码
c.部署action jar包

代码架构

oozie的服务架构如上图，但整个服务程序是由tomcat来启动，所有服务和事件的接口都在org.apache.oozie.servlet,所有的服务单例都是由org.apache.oozie.servlet.ServicesLoader来启动，看下图：

org.apache.oozie.service 的包主要是用于各功能的管理服务的单例服务的实现

编写action的代码

(先说如何部署自定义action)

部署action jar包

对于部署自定义action，我是通过分析oozie的启动脚本日记入手的，当然我使用的是ambari启动oozie，启动日记里面有一段如下的日志,这是故意调错的日志

//解压oozie.war文件
u"Execute['cd /var/tmp/oozie && /usr/hdp/current/oozie-server/bin/oozie-setup.sh prepare-war']" {'not_if': 'ls /datas/hadoop/hdp/oozie/run/oozie.pid >/dev/null 2>&1 && ps -p `cat /datas/hadoop/hdp/oozie/run/oozie.pid` >/dev/null 2>&1', 'user': 'oozie'}
2015-08-28 09:47:54,538 - Error while executing command 'restart':
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 214, in execute
    method(env)
  File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 371, in restart
    self.start(env)
  File "/var/lib/ambari-agent/cache/common-services/OOZIE/4.0.0.2.0/package/scripts/oozie_server.py", line 60, in start
    self.configure(env)
  File "/var/lib/ambari-agent/cache/common-services/OOZIE/4.0.0.2.0/package/scripts/oozie_server.py", line 53, in configure
    oozie(is_server=True)
  File "/var/lib/ambari-agent/cache/common-services/OOZIE/4.0.0.2.0/package/scripts/oozie.py", line 101, in oozie
    oozie_server_specific()
  File "/var/lib/ambari-agent/cache/common-services/OOZIE/4.0.0.2.0/package/scripts/oozie.py", line 193, in oozie_server_specific
    not_if  = no_op_test
  File "/usr/lib/python2.6/site-packages/resource_management/core/base.py", line 148, in __init__
    self.env.run()
  File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 152, in run
    self.run_action(resource, action)
  File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 118, in run_action
    provider_action()
  File "/usr/lib/python2.6/site-packages/resource_management/core/providers/system.py", line 274, in action_run
    raise ex
Fail: Execution of 'cd /var/tmp/oozie && /usr/hdp/current/oozie-server/bin/oozie-setup.sh prepare-war' returned 255.   setting OOZIE_CONFIG=${OOZIE_CONFIG:-/etc/oozie/conf}
  setting CATALINA_BASE=${CATALINA_BASE:-/usr/hdp/current/oozie-server/oozie-server}
  setting CATALINA_TMPDIR=${CATALINA_TMPDIR:-/var/tmp/oozie}
  setting OOZIE_CATALINA_HOME=/usr/lib/bigtop-tomcat
  setting JAVA_HOME=/usr/local/jdk
  setting JRE_HOME=${JAVA_HOME}
  setting OOZIE_LOG=/datas/hadoop/hdp/oozie/log
  setting CATALINA_PID=/datas/hadoop/hdp/oozie/run/oozie.pid
  setting OOZIE_DATA=/datas/hadoop/hdp/oozie/data
  setting OOZIE_HTTP_PORT=11000
  setting OOZIE_ADMIN_PORT=11001
  setting JAVA_LIBRARY_PATH=/usr/hdp/current/hadoop-client/lib/native/Linux-amd64-64
  setting OOZIE_CLIENT_OPTS="${OOZIE_CLIENT_OPTS} -Doozie.connection.retry.count=5 "
  setting CATALINA_OPTS="${CATALINA_OPTS} -Xmx2048m -XX:MaxPermSize=256m "
  setting OOZIE_CONFIG=${OOZIE_CONFIG:-/etc/oozie/conf}
  setting CATALINA_BASE=${CATALINA_BASE:-/usr/hdp/current/oozie-server/oozie-server}
  setting CATALINA_TMPDIR=${CATALINA_TMPDIR:-/var/tmp/oozie}
  setting OOZIE_CATALINA_HOME=/usr/lib/bigtop-tomcat
  setting JAVA_HOME=/usr/local/jdk
  setting JRE_HOME=${JAVA_HOME}
  setting OOZIE_LOG=/datas/hadoop/hdp/oozie/log
  setting CATALINA_PID=/datas/hadoop/hdp/oozie/run/oozie.pid
  setting OOZIE_DATA=/datas/hadoop/hdp/oozie/data
  setting OOZIE_HTTP_PORT=11000
  setting OOZIE_ADMIN_PORT=11001
  setting JAVA_LIBRARY_PATH=/usr/hdp/current/hadoop-client/lib/native/Linux-amd64-64
  setting OOZIE_CLIENT_OPTS="${OOZIE_CLIENT_OPTS} -Doozie.connection.retry.count=5 "
  setting CATALINA_OPTS="${CATALINA_OPTS} -Xmx2048m -XX:MaxPermSize=256m "

INFO: Adding extension: /usr/hdp/current/oozie-server/libext/mysql-connector-java.jar

File/Dir does no exist: /usr/hdp/current/oozie-server/oozie.war

可以看到了，oozie启动后都会重新解压和压缩oozie.war,oozie.war文件是在oozie所在路径里面，再去oozie-setup.sh脚本：

#!/bin/bash
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
#

function printUsage() {
  echo
  echo " Usage : oozie-setup.sh "
  echo " prepare-war [-d directory] [-secure] (-d identifies an alternative directory for processing jars"
  echo " -secure will configure the war file to use HTTPS (SSL))"
  echo " sharelib create -fs FS_URI [-locallib SHARED_LIBRARY] (create sharelib for oozie,"
  echo " FS_URI is the fs.default.name"
  echo " for hdfs uri; SHARED_LIBRARY, path to the"
  echo " Oozie sharelib to install, it can be a tarball"
  echo " or an expanded version of it. If ommited,"
  echo " the Oozie sharelib tarball from the Oozie"
  echo " installation directory will be used)"
  echo " (action failes if sharelib is already installed"
  echo " in HDFS)"
  echo " sharelib upgrade -fs FS_URI [-locallib SHARED_LIBRARY] (upgrade existing sharelib, fails if there"
  echo " is no existing sharelib installed in HDFS)"
  echo " db create|upgrade|postupgrade -run [-sqlfile ] (create, upgrade or postupgrade oozie db with an"
  echo " optional sql File)"
  echo " (without options prints this usage information)"
  echo
  echo " EXTJS can be downloaded from http://www.extjs.com/learn/Ext_Version_Archives"
  echo
}

#Creating temporary directory
function prepare() {
  tmpDir=/tmp/oozie-war-packing-$$
  rm -rf ${tmpDir}
  mkdir ${tmpDir}
  tmpWarDir=${tmpDir}/oozie-war
  mkdir ${tmpWarDir}
  checkExec "creating staging directory ${tmpDir}"
}

#cleans up temporary directory
function cleanUp() {
  if [ ! "${tmpDir}" = "" ]; then
    rm -rf ${tmpDir}
    checkExec "deleting staging directory ${tmpDir}"
  fi
}

#check execution of command
function checkExec() {
  if [ $? -ne 0 ]
  then
    echo
    echo "Failed: $1"
    echo
    cleanUp
    exit -1;
  fi
}

#check that a file/path exists
function checkFileExists() {
  if [ ! -e ${1} ]; then
    echo
    echo "File/Dir does no exist: ${1}"
    echo
    cleanUp
    exit -1
  fi
}

#check that a file/path does not exist
function checkFileDoesNotExist() {
  if [ -e ${1} ]; then
    echo
    echo "File/Dir already exists: ${1}"
    echo
    cleanUp
    exit -1
  fi
}


# resolve links - $0 may be a softlink
PRG="${0}"

while [ -h "${PRG}" ]; do
  ls=`ls -ld "${PRG}"`
  link=`expr "$ls" : '.*-> \(.*\)$'`
  if expr "$link" : '/.*' > /dev/null; then
    PRG="$link"
  else
    PRG=`dirname "${PRG}"`/"$link"
  fi
done

BASEDIR=`dirname ${PRG}`
BASEDIR=`cd ${BASEDIR}/..;pwd`

source ${BASEDIR}/bin/oozie-sys.sh -silent

addExtjs=""
addHadoopJars=""
additiOnalDir=""
extjsHome=""
jarsPath=""
prepareWar=""
inputWar="${OOZIE_HOME}/oozie.war"
outputWar="${CATALINA_BASE}/webapps/oozie.war"
outputWarExpanded="${CATALINA_BASE}/webapps/oozie"
secure=""
secureCOnfigsDir="${CATALINA_BASE}/conf/ssl"

while [ $# -gt 0 ]
do
  if [ "$1" = "sharelib" ] || [ "$1" = "db" ]; then
    OOZIE_OPTS="-Doozie.home.dir=${OOZIE_HOME}";
    OOZIE_OPTS="${OOZIE_OPTS} -Doozie.config.dir=${OOZIE_CONFIG}";
    OOZIE_OPTS="${OOZIE_OPTS} -Doozie.log.dir=${OOZIE_LOG}";
    OOZIE_OPTS="${OOZIE_OPTS} -Doozie.data.dir=${OOZIE_DATA}";
    OOZIE_OPTS="${OOZIE_OPTS} -Dderby.stream.error.file=${OOZIE_LOG}/derby.log"

    #Create lib directory from war if lib doesn't exist
    if [ ! -d "${BASEDIR}/lib" ]; then
      mkdir ${BASEDIR}/lib
      //解压oozie.war文件
      unzip ${BASEDIR}/oozie.war WEB-INF/lib/*.jar -d ${BASEDIR}/lib > /dev/null
      mv ${BASEDIR}/lib/WEB-INF/lib/*.jar ${BASEDIR}/lib/
      rmdir ${BASEDIR}/lib/WEB-INF/lib
      rmdir ${BASEDIR}/lib/WEB-INF
    fi

    OOZIECPPATH=""
    OOZIECPPATH=${BASEDIR}/lib/'*':${BASEDIR}/libtools/'*':${BASEDIR}/libext/'*'

    if test -z ${JAVA_HOME}; then
      JAVA_BIN=java
    else
      JAVA_BIN=${JAVA_HOME}/bin/java
    fi

    if [ "$1" = "sharelib" ]; then
      shift
      ${JAVA_BIN} ${OOZIE_OPTS} -cp ${OOZIECPPATH} org.apache.oozie.tools.OozieSharelibCLI "${@}"
    else
      shift
      ${JAVA_BIN} ${OOZIE_OPTS} -cp ${OOZIECPPATH} org.apache.oozie.tools.OozieDBCLI "${@}"
    fi
    exit $?
  elif [ "$1" = "-secure" ]; then
    shift
    secure=true
  elif [ "$1" = "-d" ]; then
    shift
    additiOnalDir=$1
  elif [ "$1" = "prepare-war" ]; then
    prepareWar=true
  else
    printUsage
    exit -1
  fi
  shift
done

if [ -e "${CATALINA_PID}" ]; then
  echo
  echo "ERROR: Stop Oozie first"
  echo
  exit -1
fi

echo

if [ "${prepareWar}" == "" ]; then
  echo "no arguments given"
  printUsage
  exit -1
else
  if [ -e "${outputWar}" ]; then
      chmod -f u+w ${outputWar}
      rm -rf ${outputWar}
  fi
  rm -rf ${outputWarExpanded}

  # Adding extension JARs

  libext=${OOZIE_HOME}/libext
  if [ "${additionalDir}" != "" ]; then
    libext=${additionalDir}
  fi

  //从libext添加自定义的jar文件路径
  if [ -d "${libext}" ]; then
    if [ `ls ${libext} | grep \.jar\$ | wc -c` != 0 ]; then
      for i in "${libext}/"*.jar; do
        echo "INFO: Adding extension: $i"
        jarsPath="${jarsPath}:$i"
        addJars="true"
      done
    fi
    if [ -f "${libext}/ext-2.2.zip" ]; then
      extjsHome=${libext}/ext-2.2.zip
      addExtjs=true
    fi
  # find war files (e.g., workflowgenerator) under /libext and deploy
    if [ `ls ${libext} | grep \.war\$ | wc -c` != 0 ]; then
      for i in "${libext}/"*.war; do
        echo "INFO: Deploying extention: $i"
        cp $i ${CATALINA_BASE}/webapps/
      done
    fi
  fi

  prepare

  checkFileExists ${inputWar}
  checkFileDoesNotExist ${outputWar}

  if [ "${addExtjs}" = "true" ]; then
    checkFileExists ${extjsHome}
  else
    echo "INFO: Oozie webconsole disabled, ExtJS library not specified"
  fi

  if [ "${addJars}" = "true" ]; then
      for jarPath in ${jarsPath//:/$'\n'}
      do
        checkFileExists ${jarPath}
      done
  fi

  #Unpacking original war
  unzip ${inputWar} -d ${tmpWarDir} > /dev/null
  checkExec "unzipping Oozie input WAR"

  compOnents=""

  if [ "${secure}" != "" ]; then
    #Use the SSL version of server.xml in oozie-server
    checkFileExists ${secureConfigsDir}/ssl-server.xml
    cp ${secureConfigsDir}/ssl-server.xml ${CATALINA_BASE}/conf/server.xml
    #Inject the SSL version of web.xml in oozie war
    checkFileExists ${secureConfigsDir}/ssl-web.xml
    cp ${secureConfigsDir}/ssl-web.xml ${tmpWarDir}/WEB-INF/web.xml
    echo "INFO: Using secure server.xml and secure web.xml"
  else
    #Use the regular version of server.xml in oozie-server
    checkFileExists ${secureConfigsDir}/server.xml
    cp ${secureConfigsDir}/server.xml ${CATALINA_BASE}/conf/server.xml
    #No need to restore web.xml because its already in the original WAR file
  fi

  if [ "${addExtjs}" = "true" ]; then
    if [ ! "${components}" = "" ];then
      compOnents="${components}, "
    fi
    compOnents="${components}ExtJS library"
    if [ -e ${tmpWarDir}/ext-2.2 ]; then
      echo
      echo "Specified Oozie WAR '${inputWar}' already contains ExtJS library files"
      echo
      cleanUp
      exit -1
    fi
    #If the extjs path given is a ZIP, expand it and use it from there
    if [ -f ${extjsHome} ]; then
      unzip ${extjsHome} -d ${tmpDir} > /dev/null
      extjsHome=${tmpDir}/ext-2.2
    fi
    #Inject the library in oozie war
    cp -r ${extjsHome} ${tmpWarDir}/ext-2.2
    checkExec "copying ExtJS files into staging"
  fi

  if [ "${addJars}" = "true" ]; then
    if [ ! "${components}" = "" ];then
      compOnents="${components}, "
    fi
    compOnents="${components}JARs"
    //逐个复制自定义jar包到oozie.war的解压路径当中
    for jarPath in ${jarsPath//:/$'\n'}
    do
      found=`ls ${tmpWarDir}/WEB-INF/lib/${jarPath} 2> /dev/null | wc -l`
      checkExec "looking for JAR ${jarPath} in input WAR"
      if [ ! $found = 0 ]; then
        echo
        echo "Specified Oozie WAR '${inputWar}' already contains JAR ${jarPath}"
        echo
        cleanUp
        exit -1
      fi
      //复制过程
      cp ${jarPath} ${tmpWarDir}/WEB-INF/lib/
      checkExec "copying jar ${jarPath} to staging"
    done
  fi

  #Creating new Oozie WAR
  currentDir=`pwd`
  cd ${tmpWarDir}
  zip -r oozie.war * > /dev/null
  checkExec "creating new Oozie WAR"
  cd ${currentDir}

  #copying new Oozie WAR to asked location
  cp ${tmpWarDir}/oozie.war ${outputWar}
  checkExec "copying new Oozie WAR"

  echo
  echo "New Oozie WAR file with added '${components}' at ${outputWar}"
  echo
  cleanUp

  if [ "$?" != "0" ]; then
    exit -1
  fi

  echo

  echo "INFO: Oozie is ready to be started"

  echo

fi

可以看到oozie部署自定义action从其home目录下的libext目录添加的，当然自定义action的jar包中必须包括自定义action的xsd schema文件，此文件是用于校验workflow的，如果对xsd schema不熟悉，请自行网上查阅；
自此，需要为oozie配置自定义的action信息，主要是要oozie-site.xml下的oozie.service.ActionService.executor.ext.classes添加自定义的action类以及oozie.service.SchemaService.wf.ext.schemas下的自定义xsd scheama

下面是测试用的自定义action项目架构图

maven项目依赖为：

<dependency>
    <groupId>org.apache.ooziegroupId>
    <artifactId>oozie-hadoopartifactId>
    <version>2.3.0.oozie-4.1.0version>
dependency>

<dependency>
    <groupId>org.apache.ooziegroupId>
    <artifactId>oozie-coreartifactId>
    <version>4.1.0version>
dependency>