Jenkins Installation

OS: CentOS Linux release 7.5.1804 (Core)

Adding new repository for Jenkins package

[root@andregonzaga1c ~]# wget -O /etc/yum.repos.d/jenkins.repo http://pkg.jenkins-ci.org/redhat/jenkins.repo

Importing our package rpm key for security purpose

[root@andregonzaga1c yum.repos.d]# sudo rpm --import https://jenkins-ci.org/redhat/jenkins-ci.org.key

Update our package cache

[root@andregonzaga1c yum.repos.d]# yum update

Installing Jenkins

[root@andregonzaga1c yum.repos.d]# yum install jenkins

Installing Java Openjdk package - Jenkins rely on this to work

[root@andregonzaga1c yum.repos.d]# yum install java-1.8.0-openjdk

Check if any firewall configuration is denying any access

Unit firewalld.service could not be found.
[root@andregonzaga1c yum.repos.d]# systemctl status iptables
Unit iptables.service could not be found.

Start and enable Jenkins to run after restart

[root@andregonzaga1c yum.repos.d]# systemctl start jenkins
[root@andregonzaga1c yum.repos.d]# systemctl enable jenkins

Testing Jenkins response on 8080

[root@andregonzaga1c yum.repos.d]# yum install telnet
[root@andregonzaga1c yum.repos.d]# telnet localhost 8080
say "hello" and check if it responds 

Setting up proxy configuration to work around a redirection port from 80 to 8080

[root@andregonzaga1c yum.repos.d]# yum install ngnix
[root@andregonzaga1c yum.repos.d]# systemctl start nginx
[root@andregonzaga1c yum.repos.d]# systemctl enable nginx

[root@andregonzaga1c nginx]# vi /etc/nginx/nginx.conf

before location / { add: proxy_pass http://127.0.0.1:8080;

Restart nginx

[root@andregonzaga1c nginx]# systemctl restart nginx

Installing elinks and testing against jenkins

[root@andregonzaga1c nginx]# yum install elinks

• elinks http://127.0.0.1:8080

• elinks http://127.0.0.1

Enabling SeLinux and testing again

[root@andregonzaga1c nginx]# setenforce 0 [root@andregonzaga1c nginx]# getenforce

• elinks http://127.0.0.1

Installing package to set up SeLinux

[root@andregonzaga1c nginx]# yum install -y setroubleshoot-server selinux-policy-devel

Checking default http ports for SeLinux

[root@andregonzaga1c nginx]# sepolicy network -t http_port_t

Enabling new Port 8080 to the SeLinux

[root@andregonzaga1c nginx]# semanage port -m -t http_port_t -p tcp 8080 [root@andregonzaga1c nginx]# sepolicy network -t http_port_t

Enabling SeLinux default policy again

[root@andregonzaga1c nginx]# setenforce 1 [root@andregonzaga1c nginx]# getenforce

Open your browser and access your Jenkins address

How to check temp password for Jenkins installation

[root@andregonzaga1c nginx]# cat /var/lib/jenkins/secrets/initialAdminPassword

**After Jenkins installation check ** Manage Jenkins on left menu and look at the error about proxy reverse.

How to fix proxy reverse - Check also in Jenkins UI where example is available

[root@andregonzaga1c nginx]# vi /etc/nginx/nginx.conf

Add the following content after proxy_pass http://127.0.0.1:8080;

 ``` proxy_redirect     default;
  proxy_http_version 1.1;
  proxy_set_header   Host              $host;
  proxy_set_header   X-Real-IP         $remote_addr;
  proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
  proxy_set_header   X-Forwarded-Proto $scheme;
  proxy_max_temp_file_size 0;
  #this is the maximum upload size
  client_max_body_size       10m;
  client_body_buffer_size    128k;
  proxy_connect_timeout      90;
  proxy_send_timeout         90;
  proxy_read_timeout         90;
  proxy_buffering            off;
  proxy_request_buffering    off; # Required for HTTP CLI commands in Jenkins > 2.54
  proxy_set_header Connection ""; # Clear for keepalive

`[root@andregonzaga1c nginx]# systemctl restart nginx`