使用Jenkins时，如果GIT_COMMIT无变化，跳过构建

使用Jenkins时，如果GIT_COMMIT无变化，跳过构建  使用插件： conditional-buildstepA buildstep wrapping any number of other buildsteps, controlling their execution based on a defined condition (e.g. BuildParameter).wiki： https://wiki.jenkins-ci.org/display/JENKINS/Conditional+BuildStep+Plugin 

如下图所示，如果环境变量GIT_PREVIOUS_SUCCESSFUL_COMMIT不存在，或者GIT_COMMIT和GIT_PREVIOUS_SUCCESSFUL_COMMIT不同，才会执行构建

 上图中脚本如下：

#!/bin/bashif [ ! $GIT_PREVIOUS_SUCCESSFUL_COMMIT ];then    echo "GIT_PREVIOUS_SUCCESSFUL_COMMIT is not exists."    exit 0else    echo "GIT_COMMIT=[$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"        exit 0    fifi