判斷Git是否有新的提交

 公司要搭建CI，有這樣一個需求：判斷Git是否有新的提交，如果有的話拉取代碼構建，如果沒有不構建，Jenkins的搭建這里就不贅述了，主要講一下判斷這里。

Jenkins需要安裝插件Conditional BuildStep，地址https://wiki.jenkins-ci.org/display/JENKINS/Conditional+BuildStep+Plugin

配置如下：

執行腳本：

#!/bin/bash
if [ ! $GIT_PREVIOUS_SUCCESSFUL_COMMIT ];then
    echo "GIT_PREVIOUS_SUCCESSFUL_COMMIT is not exists."
    exit 0
else
    echo "GIT_COMMIT=[$GIT_COMMIT],GIT_PREVIOUS_SUCCESSFUL_COMMIT=[$GIT_PREVIOUS_SUCCESSFUL_COMMIT]"
    if [ $GIT_PREVIOUS_SUCCESSFUL_COMMIT == $GIT_COMMIT ];then
        echo "GIT_COMMIT is equals to GIT_PREVIOUS_SUCCESSFUL_COMMIT,skip build."
        exit -1
    else
        echo "GIT_COMMIT is not equals to GIT_PREVIOUS_SUCCESSFUL_COMMIT"
        sh build_using_xctool.sh//這里是有代碼更新的條件下需要執行的代碼，我這里是跑一個腳本
        exit 0
    fi
fi

判斷的條件是本地的Git_Commit跟遠端進行對比，不一致就代表有新的代碼提交，執行操作，否則exit