oozie调用shell

<!--
  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.
-->
<workflow-app xmlns="uri:oozie:workflow:0.4" name="shell-wf">
    <start to="shell-node"/>
    <action name="shell-node">
        <shell xmlns="uri:oozie:shell-action:0.2">
            <job-tracker>${jobTracker}</job-tracker>
            <name-node>${nameNode}</name-node>
            <configuration>
                <property>
                    <name>mapred.job.queue.name</name>
                    <value>${queueName}</value>
                </property>
            </configuration>
            <exec>echo</exec>
            <argument>my_output=Hello Oozie</argument>
            <capture-output/>
        </shell>
        <ok to="check-output"/>
        <error to="fail"/>
    </action>
    <decision name="check-output">
        <switch>
            <case to="end">
                ${wf:actionData('shell-node')['my_output'] eq 'Hello Oozie'}
            </case>
            <default to="fail-output"/>
        </switch>
    </decision>
    <kill name="fail">
        <message>Shell action failed, error message[${wf:errorMessage(wf:lastErrorNode())}]</message>
    </kill>
    <kill name="fail-output">
        <message>Incorrect output, expected [Hello Oozie] but was [${wf:actionData('shell-node')['my_output']}]</message>
    </kill>
    <end name="end"/>
</workflow-app>

输出必须是键值对，才能被oozie捕获