在Jenkins作业结束时运行groovy脚本

我需要运行一个groovy后期构建脚本来进行一些清理,因此我已经安排了以下脚本:

def sout = new StringBuilder(), serr = new StringBuilder()
def proc = '/usr/bin/docker stop mysql'.execute()
proc.consumeProcessOutput(sout, serr)
proc.waitForOrKill(1000)

虽然如果我登录机器,命令'/usr/bin/docker stop mysql'可以工作,但是在执行groovy脚本时,会引发以下错误:

java.io.IOException: Cannot run program "/usr/bin/docker": error=2, No such file or directory
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
    at java.lang.Runtime.exec(Runtime.java:620)
    at java.lang.Runtime.exec(Runtime.java:450)
    at java.lang.Runtime.exec(Runtime.java:347)
    at org.codehaus.groovy.runtime.ProcessGroovyMethods.execute(ProcessGroovyMethods.java:533)
    at org.codehaus.groovy.runtime.dgm$894.invoke(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoMetaMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:274)
    at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:56)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
    at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:157)
    at org.kohsuke.groovy.sandbox.GroovyInterceptor.onMethodCall(GroovyInterceptor.java:23)
    at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:104)
    at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:155)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:159)
    at org.kohsuke.groovy.sandbox.impl.Checker$checkedCall$0.callStatic(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallStatic(CallSiteArray.java:56)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callStatic(AbstractCallSite.java:194)
    at Script1.run(Script1.groovy:2)

你知道groovy引擎为什么找不到'docker'命令吗? 谢谢!