Jenkins 如何重置密码
Reset Jenkins Admin Password
重置 Jenkins 管理员密码
1、重中之重：先备份
Make a backup copy of a Jenkins config file (this step is important as after resetting the Jenkins admin password we would need to restore the previous settings):
首先第一步，修改之前先备份
$ cp /var/lib/jenkins/config.xml /var/lib/jenkins/config.xml.back
2、修改文件
打开配置文件： /var/lib/jenkins/config.xml ，禁止掉：and disable the security:
<useSecurity>false</useSecurity>
3、重启服务
$ systemctl restart jenkins
4、此时访问 jenkins，则不再需要密码
登录后做如下修改：
Go to the Jenkins UI (you won’t be asked for any credentials this time) and reset the admin password:
Navigate to "Manage Jenkins" -> "Security" -> "Configure Global Security" -> "Authentication"
Select the "Security Realm" (e.g. "Jenkins’ own user database") and click on "Save"
Go to "People" -> Click on a username for which you want to change the password (e.g. admin) -> "Configure" -> Enter a new password in the "Password" and "Confirm password" fields and click on "Save"
5、修改完成后，恢复之前备份的xml，重启服务
Once the admin password is reset, restore the previous /var/lib/jenkins/config.xml file and restart Jenkins:
$ mv /var/lib/jenkins/config.xml.back /var/lib/jenkins/config.xml
$ systemctl restart jenkins
