安装
将Jenkins存储库添加到yum repos，并从此安装Jenkins。
sudo wget -O /etc/yum.repos.d/jenkins.repo http://pkg.jenkins-ci.org/redhat/jenkins.repo
sudo rpm --import https://jenkins-ci.org/redhat/jenkins-ci.org.key
sudo yum install jenkins
sudo service jenkins start
## sudo service jenkins start/stop/restart/status
cat /var/lib/jenkins/secrets/initialAdminPassword
