1、安裝GitLab：

①、安裝需要的擴充套件/應用：

yum -y install curl policycoreutils openssh-server openssh-clients postfix cronie
yum -y install readline readline-devel ncurses-devel gdbm-devel glibc-devel tcl-devel openssl-devel expat-devel db4-devel byacc sqlite-devel libyaml libyaml-devel libffi libffi-devel libxml2 libxml2-devel
 
 libxslt libxslt-devel libicu libicu-devel system-config-firewall-tui crontabs logwatch logrotate perl-Time-HiRes git cmake libcom_err-devel libcom_err-devel git patch gcc-c++ zlib-devel make autoconf automake libtool bison python python-docutils wget ruby
sudo systemctl enable sshd
sudo systemctl start sshd
sudo systemctl enable postfix
sudo systemctl start postfix
sudo chkconfig postfix on
 

②、更換Ruby源：

gem sources -r https://rubygems.org/
gem sources -a https://ruby.taobao.org/

③、新增yum源，使用yum源安裝：

Ⅰ、這種是官方的yum源，在國內速度可能會很慢：

curl -sS https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/script.rpm.sh | sudo bash
sudo yum -y install gitlab-ce

Ⅱ、使用國內的yum源：
PS.具體源內容可以參考官方說明：
修改使用GitLab國內源

；
首先新增原始檔

sudo vi /etc/yum.repos.d/gitlab_gitlab-ce.repo

修改原始檔內容：

[gitlab-ce]
name=gitlab-ce
baseurl=http://mirrors.tuna.tsinghua.edu.cn/gitlab-ce/yum/el7
repo_gpgcheck=0
gpgcheck=0
enabled=1
gpgkey=https://packages.gitlab.com/gpg.key

然後執行如下命令：

sudo yum makecache
sudo yum -y install gitlab-ce

④、用預設配置配置GitLab：

sudo gitlab-ctl reconfigure

⑤、按個人需求修改GitLab配置：

PS.因為這裡要用已有的Nginx作為GitLab的伺服器，所以要先進行配置，GitLab的配置檔案位置：

/etc/gitlab/gitlab.rb

我這裡因為提前配置了gitlab的域名是http://git.xxx.com，接下來修改/etc/gitlab/gitlab.rb以下內容，在修改內容裡要注意一點就是web_server設定的值是你nginx的配置，注意每行前面不要有空格，需要特別注意 的是因為GitLab使用的是Ruby，預設開啟埠是8080：

# note the 'https' below
external_url 'http://git.xxx.com'

# Set the web server
web_server['external_users'] = ['www']

# Disable the built-in nginx
nginx['enable'] = false

上面是gitlab配置檔案需要修改的地方，重新生成配置：

sudo gitlab-ctl reconfigure

接下來配置Nginx虛擬主機，

⑥、新增nginx虛擬主機，支援gitlab：

新增gitlab.conf：

vi /usr/local/nginx/conf/vhost/gitlab.conf

在gitlab.conf中新增以下模板內容：

## GitLab
##
## Modified from nginx http version
## Modified from http://blog.phusion.nl/2012/04/21/tutorial-setting-up-gitlab-on-debian-6/
## Modified from https://raymii.org/s/tutorials/Strong_SSL_Security_On_nginx.html
##
## Lines starting with two hashes (##) are comments with information.
## Lines starting with one hash (#) are configuration parameters that can be uncommented.
##
##################################
##        CONTRIBUTING          ##
##################################
##
## If you change this file in a Merge Request, please also create
## a Merge Request on https://gitlab.com/gitlab-org/omnibus-gitlab/merge_requests
##
###################################
##         configuration         ##
###################################
##
## See installation.md#using-https for additional HTTPS configuration details.

upstream gitlab-workhorse {
  server unix:/var/opt/gitlab/gitlab-workhorse/socket fail_timeout=0;
}

## HTTPS host
server {
  listen  80;
  server_name git.xxx.com; ## Replace this with something like gitlab.example.com
  server_tokens off; ## Don't show the nginx version number, a security best practice
  root /opt/gitlab/embedded/service/gitlab-rails/public;
  include pagespeed.conf;
  ## Individual nginx logs for this GitLab vhost
  access_log  /data/log/nginx/gitlab.access.log;
  error_log   /data/log/nginx/gitlab.error.log;
  location / {
    client_max_body_size 0;
    gzip on;

    ## https://github.com/gitlabhq/gitlabhq/issues/694
    ## Some requests take more than 30 seconds.
    proxy_read_timeout      300;
    proxy_connect_timeout   300;
    proxy_redirect          off;

    proxy_http_version 1.1;

    proxy_set_header    Host                $http_host;
    proxy_set_header    X-Real-IP           $remote_addr;
    proxy_set_header    X-Forwarded-Ssl     off;
    proxy_set_header    X-Forwarded-For     $proxy_add_x_forwarded_for;
    proxy_set_header    X-Forwarded-Proto   $scheme;
    proxy_set_header    Upgrade $http_upgrade;
    proxy_set_header    Connection "upgrade";
    proxy_pass http://gitlab-workhorse;
  }
}

⑦、修改防火牆設定：

#為public域開放tcp協議的8080埠
firewall-cmd --zone=public --add-port=8080/tcp --permanent
#為public域新增http服務
firewall-cmd --zone=public --add-service=http --permanent
#重啟firewall服務
firewall-cmd --reload

⑧、啟動：

啟動GitLab：

sudo gitlab-ctl start/stop/restart

重啟Nginx：

nginx -s reload
nginx -s reopen

接下來就可以訪問git.xxx.com操作gitlab了。

⑨、修改GitLab預設影象路徑：

由於GitLab使用的是Gravatar的頭像，但Gravatar服務在國內不能正常訪問http的影象資訊導致Gitlab的頭像全都裂了，可以採用下面的方法來解決這個問題：
修改/etc/gitlab/gitlab.rb檔案中gravatar_plain_url的值，開啟檔案，搜尋gravatar_plain_url，如果想要在原來的基礎上改，就去掉該行前面的#，然後修改gravatar_plain_url值為

http://gravatar.duoshuo.com/avatar/%{hash}?s=%{size}&d=identicon

然後執行下面的命令：

sudo gitlab-ctl reconfigure 
sudo gitlab-rake cache:clear RAILS_ENV=production
sudo gitlab-ctl restart

完成之後GitLab使用的就是國內多說的頭像了，如果你的網站採用的是https模式，可以修改gitlab_rails['gravatar_plain_url']值為如下內容：

gitlab_rails['gravatar_plain_url'] = 'https://secure.gravatar.com/avatar/%{hash}?s=%{size}&d=identicon'

然後執行上面的重新配置/重啟命令。

2、安裝Jenkins：

①、安裝yum源：

cd ~&&  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

②、安裝jenkins並修改啟動埠：

sudo yum -y install java jenkins

修改/etc/sysconfig/jenkins配置：

JENKINS_PORT="8081"

③、啟動jenkins，設定開機啟動：

sudo service jenkins start/stop/restart
sudo chkconfig jenkins on

④、修改防火牆設定：

firewall-cmd --zone=public --add-port=8081/tcp --permanent
firewall-cmd --zone=public --add-service=http --permanent
firewall-cmd --reload

⑤、使用Nginx作為Web伺服器：

安裝完成之後，訪問http://localhost:8080/就可以看到jenkins的主頁面了，然後根據提示輸入隨機生成的密碼，登入jenkins，如果想使用已有的Web伺服器訪問jenkins，可以進行如下配置（我這裡直接使用Nginx，Apache的配置官方有說明），

vi /etc/nginxhost/jenkins.conf 

在配置檔案中寫入如下配置：

server {
  listen          80;       # Listen on port 80 for IPv4 requests
  server_name     jenkins.xxx.com;
  server_tokens   off;
  #this is the jenkins web root directory (mentioned in the /etc/default/jenkins file)
  root            /var/run/jenkins/war/;
  include pagespeed.conf;
  include proxy.conf;
  access_log      /data/log/nginx/jenkins.access.log;
  error_log       /data/log/nginx/jenkins.error.log;

  location ~ "^/static/[0-9a-fA-F]{8}\/(.*)$" {

    #rewrite all static files into requests to the root
    #E.g /static/12345678/css/something.css will become /css/something.css
    rewrite "^/static/[0-9a-fA-F]{8}\/(.*)" /$1 last;
  }

  location /userContent {
        #have nginx handle all the static requests to the userContent folder files
        #note : This is the $JENKINS_HOME dir
        root /var/lib/jenkins/;
        if (!-f $request_filename){
           #this file does not exist, might be a directory or a /**view** url
           rewrite (.*) /$1 last;
           break;
        }
        sendfile on;
  }

  location @jenkins {
      sendfile off;
      proxy_pass         http://127.0.0.1:8081;
      proxy_redirect     default;
  }
  location / {

     # Optional configuration to detect and redirect iPhones
      if ($http_user_agent ~* '(iPhone|iPod)') {
          rewrite ^/$ /view/iphone/ redirect;
      }

      try_files $uri @jenkins;
   }
}

重啟Nginx，訪問http://jenkins.xxx.com就可以訪問jenkins了，安裝完成更新外掛時會發現外掛更新比較慢，可以設定新的更新站點，不用官方的更新點：
①、首先測試更新資料是否可用：
訪問http://mirror.xmission.com/jenkins/updates/current/update-center.json，如果得到結果就說明更新點可用，如果不可訪問，就直接使用官方預設的更新源；
②、測試可用之後在“Manage Jenkins”——>“Manage Plugins”——>“Advanced”中設定“Update Site”為如下地址：

http://mirror.xmission.com/jenkins/updates/current/update-center.json

3、安裝Gerrit：

①、下載gerrit2.12.2：

cd ~ && wget https://gerrit-releases.storage.googleapis.com/gerrit-2.12.2.war

②、安裝前準備：
Gerrit支援MySQL、PostgreSQL等，我這裡在使用MySQL時發現有一個建立資料表報錯的提示，也不願意再去折騰，就改用PostgreSQL，PostgreSQL的安裝使用，請參考文章：Centos7安裝PostgreSQL9.5，安裝完成之後，為Gerrit建立資料庫reviewdb：

createdb -h 127.0.0.1 -p 5432 -U postgres reviewdb

輸入postgres的密碼後就建立了資料庫reviewdb；
③、安裝gerrit至/var/opt/gerrit下

cd ~ && java -jar gerrit-2.12.2.war init -d /var/opt/gerrit 

操作及顯示結果如下：

*** Gerrit Code Review 2.12.2
*** 

Create '/var/opt/gerrit'       [Y/n]? y

*** Git Repositories
*** 

Location of Git repositories   [git]: 

*** SQL Database
*** 

Database server type           [h2]: postgresql
Server hostname                [localhost]: 
Server port                    [(postgresql default)]: 
Database name                  [reviewdb]: 
Database username              [root]: postgres
postgres's password            : 
              confirm password : 

*** Index
*** 

Type                           [LUCENE/?]: 

*** User Authentication
*** 

Authentication method          [OPENID/?]: http
Get username from custom HTTP header [y/N]? 
SSO logout URL                 : 
Enable signed push support     [y/N]? 

*** Review Labels
*** 

Install Verified label         [y/N]? 

*** Email Delivery
*** 

SMTP server hostname           [localhost]: 
SMTP server port               [(default)]: 
SMTP encryption                [NONE/?]: 
SMTP username                  : [email protected]
[email protected]'s password : 
              confirm password : 

*** Container Process
*** 

Run as                         [root]: 
Java runtime                   [/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.101-2.6.6.1.el7_2.x86_64/jre]: 
Copy gerrit-2.12.2.war to /var/opt/gerrit/bin/gerrit.war [Y/n]? 
Copying gerrit-2.12.2.war to /var/opt/gerrit/bin/gerrit.war

*** SSH Daemon
*** 

Listen on address              [*]: 
Listen on port                 [29418]: 

Gerrit Code Review is not shipped with Bouncy Castle Crypto SSL v152
  If available, Gerrit can take advantage of features
  in the library, but will also function without it.
Download and install it now [Y/n]? 
Downloading http://www.bouncycastle.org/download/bcpkix-jdk15on-152.jar ... Failed to clean up lib: /var/opt/gerrit/lib/bcpkix-jdk15on-152.jar
 !! FAIL !!


error: http://www.bouncycastle.org/download/bcpkix-jdk15on-152.jar: 302 Found
Please download:

  http://www.bouncycastle.org/download/bcpkix-jdk15on-152.jar

and save as:

  /var/opt/gerrit/lib/bcpkix-jdk15on-152.jar

Press enter to continue 
Continue without this library  [Y/n]? 
Generating SSH host key ... rsa(simple)... done

*** HTTP Daemon
*** 

Behind reverse proxy           [y/N]? y
Proxy uses SSL (https://)      [y/N]? 
Subdirectory on proxy server   [/]: 
Listen on address              [*]:    
Listen on port                 [8081]: 8082
Canonical URL                  [http://localhost/]: http://g.example.com

*** Plugins
*** 

Installing plugins.
Install plugin singleusergroup version v2.12.2 [y/N]? y
Install plugin commit-message-length-validator version v2.12.2 [y/N]? y
Install plugin reviewnotes version v2.12.2 [y/N]? y
Install plugin replication version v2.12.2 [y/N]? y
Install plugin download-commands version v2.12.2 [y/N]? y
Initializing plugins.
No plugins found with init steps.

Initialized /var/opt/gerrit
Executing /var/opt/gerrit/bin/gerrit.sh start
Starting Gerrit Code Review: OK
Waiting for server on g.maidoumi.cn:80 ... OK
Opening http://g.example.com/#/admin/projects/ ...FAILED
Open Gerrit with a JavaScript capable browser:
  http://g.example.com/#/admin/projects/

④、安裝完成，設定Gerrit：
新增檔案gerritcodereview：

vi /etc/default/gerritcodereview

檔案內容如下：

GERRIT_SITE=/var/opt/gerrit

⑤、啟動Gerrit，並設定Gerrit自啟動：
建立啟動軟鏈：

ln -sf /var/opt/gerrit/bin/gerrit.sh /usr/bin/gerrit

啟動Gerrit：

gerrit start

設定自啟動：

echo -e 'gerrit start\n' >> /etc/rc.local

⑥、設定Gerrit認證：
使用htpasswd命令為管理雲使用者生成http認證配置檔案,如果沒有htpasswd檔案需要安裝apache2-utils包。
新增admin使用者的驗證檔案，放在/var/opt/gerrit下，並將admin作為管理員：

cd /var/opt/gerrit && htpasswd -d htpasswd.conf admin

輸入兩次密碼之後就添加了admin使用者，以後新增gerrit使用者時,同樣需要先為其配置http認證,然後使用者登入後gerrit會為其自動生成使用者帳號,名字與http認證名字一致，第一次登入成功之後就會要求你設定基本驗證。
⑦、設定Nginx代理：

vi /etc/nginxhost/gerrit.conf

檔案內容如下：

server {
        listen       80;
        server_name  g.example.com;
        ## Don't show the nginx version number, a security best practice
        server_tokens off;
        include proxy.conf;
        include pagespeed.conf;
        #error_page  404              /404.html;
        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
        access_log  /data/log/nginx/gerrit.access.log  main;
        error_log   /data/log/nginx/gerrit.error.log;
        location / {
                auth_basic              "Gerrit2 Code Review";
                auth_basic_user_file    /var/opt/gerrit/htpasswd.conf;
                proxy_pass              http://127.0.0.1:8082;
                proxy_set_header        X-Forwarded-For $remote_addr;
                proxy_set_header        Host $host;
        }
        location /login/ {
                proxy_pass              http://127.0.0.1:8082;
                proxy_set_header        X-Forwarded-For $remote_addr;
                proxy_set_header        Host $host;
        }
        location ~ .*＼.(gif|jpg|jpeg|png|bmp|swf)$
        {
                expires       1d;
        }
        location ~ .*＼.(js|css|html)?$
        {
                expires       1d;
        }
}

PS.配置檔案中的proxy.conf;和pagespeed.conf具體寫法請參考我之前的文章。
之後重啟Nginx和Gerrit：

nginx -s reload
nginx -s reopen
gerrit restart

至此CI系統所需的三個產品都完成了安裝，接下來就是配合使用了。