安装 jenkins

2. yum install jenkins -y

2.安装完后卡住了，如图

首先命令行启动 没有报错：/usr/bin/java -Djava.awt.headless=true -jar /usr/share/java/jenkins.war –webroot=%C/jenkins/war –httpPort=8080

最后找资料发现是 更新配置有问题：
vim /var/lib/jenkins/hudson.model.UpdateCenter.xml

重新启动jenkins问题解决

升级jenkins

3. yum update jenkins

升级后发现无法启动，报错 java 版本过低，只能升级java版本或者回退jenkins

2.选择升级 java: yum install java-11-openjdk* -y

并切换java版本：

alternatives –config java

There are 2 programs which provide ‘java’.

Selection Command

———————————————–

1 java-11-openjdk.x86_64 (/usr/lib/jvm/java-11-openjdk-11.0.17.0.8-2.el7_9.x86_64/bin/java)

*+ 2 java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.342.b07-1.el7_9.x86_64/jre/bin/java)

Enter to keep the current selection[+], or type selection number : 1