方法一

輸出docker image鏡像標簽給IMAGE_TAG

def IMAGE_TAG = sh(script: '''docker images | grep ${SERVER_NAME} | grep $NAME_SPACE | awk '{print $2}'|grep ${BUILD_NUMBER}''', returnStdout: true) 

另外，如果想輸出docker image命令執行結果給IMAGE_TAG

def IMAGE_TAG = sh(script: '''docker images | grep ${SERVER_NAME} | grep $NAME_SPACE | awk '{print $2}'|grep ${BUILD_NUMBER}''', returnStatus: true) 

方法二

其實就是拆分上面的語句

先使用shell把執行后的結果賦值到一個文本，然后讀取文本內容賦值給IMAGE_TAG

sh '''docker images | grep ${SERVER_NAME} | grep $NAME_SPACE | awk '{print $2}'|grep ${BUILD_NUMBER} > image.txt'''
def IMAGE_TAG = readFile('image.txt').trim()