问题：

502 Whoops, GitLab is taking too much time to respond.

日志：

[root@cs12-66-gitlab ~]# my gitlab-ctl tail
-bash: my: command not found
[root@cs12-66-gitlab ~]# gitlab-ctl tail
==> /var/log/gitlab/gitlab-shell/gitlab-shell.log <==
# Logfile created on 2018-02-02 14:34:26 +0800 by logger.rb/56438==> /var/log/gitlab/gitlab-rails/gitlab-rails-db-migrate-2018-02-02-14-34-39.log <==-> 0.3182s== Seed from /opt/gitlab/embedded/service/gitlab-rails/db/fixtures/production/001_admin.rb
Administrator account created:login:    root
password: You'll be prompted to create one on your first visit.== Seed from /opt/gitlab/embedded/service/gitlab-rails/db/fixtures/production/010_settings.rb==> /var/log/gitlab/gitlab-rails/production.log <==
Started GET "/" for 10.100.16.218 at 2018-02-02 14:54:06 +0800
Started GET "/-/metrics" for 127.0.0.1 at 2018-02-02 14:54:06 +0800
Processing by MetricsController#index as HTML
Completed 200 OK in 3ms (Views: 0.8ms | ActiveRecord: 0.0ms)
Processing by RootController#index as HTML
Redirected to http://git.tuandai888.com/users/sign_in
Filter chain halted as :redirect_unlogged_user rendered or redirected
Completed 302 Found in 9ms (ActiveRecord: 0.0ms)
Started GET "/users/sign_in" for 10.100.16.218 at 2018-02-02 14:54:10 +0800
Processing by SessionsController#new as HTML==> /var/log/gitlab/gitlab-rails/grpc.log <==
# Logfile created on 2018-02-02 14:41:50 +0800 by logger.rb/56438==> /var/log/gitlab/gitlab-rails/production_json.log <==
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":3.63,"view":0.5,"db":0.0,"time":"2018-02-02T06:52:06.991Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":4.42,"view":0.96,"db":0.0,"time":"2018-02-02T06:52:21.998Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":17.59,"view":13.91,"db":0.0,"time":"2018-02-02T06:52:38.632Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":4.71,"view":1.08,"db":0.0,"time":"2018-02-02T06:52:52.001Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":3.6,"view":0.55,"db":0.0,"time":"2018-02-02T06:53:06.992Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":4.08,"view":0.54,"db":0.0,"time":"2018-02-02T06:53:21.984Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":3.64,"view":0.42,"db":0.0,"time":"2018-02-02T06:53:36.985Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":4.94,"view":0.73,"db":0.0,"time":"2018-02-02T06:53:51.985Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":200,"duration":4.72,"view":0.84,"db":0.0,"time":"2018-02-02T06:54:06.991Z","params":{},"remote_ip":null,"user_id":null,"username":null}
{"method":"GET","path":"/","format":"html","controller":"RootController","action":"index","status":302,"duration":10.83,"view":0.0,"db":0.0,"location":"http://git.tuandai888.com/users/sign_in","time":"2018-02-02T06:54:10.479Z","params":{},"remote_ip":"10.100.16.218","user_id":null,"username":null}==> /var/log/gitlab/gitlab-rails/api_json.log <==
# Logfile created on 2018-02-02 14:41:51 +0800 by logger.rb/56438==> /var/log/gitlab/gitlab-rails/application.log <==
# Logfile created on 2018-02-02 14:42:32 +0800 by logger.rb/56438
February 02, 2018 14:42: User "Administrator" (admin@example.com) was created==> /var/log/gitlab/logrotate/current <====> /var/log/gitlab/unicorn/current <==
2018-02-02_06:42:37.56441 starting new unicorn master
2018-02-02_06:49:48.90547 adopted new unicorn master 3906==> /var/log/gitlab/unicorn/unicorn_stderr.log <==
I, [2018-02-02T14:49:47.581121 #4594]  INFO -- : worker=0 ready
I, [2018-02-02T14:49:47.612613 #4597]  INFO -- : worker=1 ready
I, [2018-02-02T14:49:47.674536 #4600]  INFO -- : worker=2 ready
I, [2018-02-02T14:49:47.710865 #4603]  INFO -- : worker=3 ready
I, [2018-02-02T14:49:47.756704 #4606]  INFO -- : worker=4 ready
I, [2018-02-02T14:49:47.825869 #3906]  INFO -- : master process ready
I, [2018-02-02T14:49:47.836401 #4609]  INFO -- : worker=5 ready
I, [2018-02-02T14:49:47.887782 #4612]  INFO -- : worker=6 ready
I, [2018-02-02T14:49:47.909891 #4615]  INFO -- : worker=7 ready
I, [2018-02-02T14:49:47.940642 #4618]  INFO -- : worker=8 ready==> /var/log/gitlab/unicorn/unicorn_stdout.log <====> /var/log/gitlab/sidekiq/current <==
2018-02-02_06:52:59.51350 127.0.0.1 - - [02/Feb/2018:14:52:59 CST] "GET /metrics HTTP/1.1" 200 25
2018-02-02_06:52:59.51358 - -> /metrics
2018-02-02_06:53:14.51410 127.0.0.1 - - [02/Feb/2018:14:53:14 CST] "GET /metrics HTTP/1.1" 200 25
2018-02-02_06:53:14.51417 - -> /metrics
2018-02-02_06:53:29.51384 127.0.0.1 - - [02/Feb/2018:14:53:29 CST] "GET /metrics HTTP/1.1" 200 25
2018-02-02_06:53:29.51390 - -> /metrics
2018-02-02_06:53:44.51387 127.0.0.1 - - [02/Feb/2018:14:53:44 CST] "GET /metrics HTTP/1.1" 200 25
2018-02-02_06:53:44.51392 - -> /metrics
2018-02-02_06:53:59.51637 127.0.0.1 - - [02/Feb/2018:14:53:59 CST] "GET /metrics HTTP/1.1" 200 25
2018-02-02_06:53:59.51640 - -> /metrics==> /var/log/gitlab/gitlab-workhorse/current <==
2018-02-02_06:46:40.87969 10.100.12.66 @ - - [2018-02-02 14:46:40.877704109 +0800 CST] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36" 0.001910
2018-02-02_06:46:40.89513 2018/02/02 14:46:40 Send static file "/opt/gitlab/embedded/service/gitlab-rails/public/favicon.ico" ("") for GET "/favicon.ico"
2018-02-02_06:46:40.89566 10.100.12.66 @ - - [2018-02-02 14:46:40.89417661 +0800 CST] "GET /favicon.ico HTTP/1.1" 200 5430 "http://10.100.12.66/" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36" 0.001187
2018-02-02_06:47:25.68625 2018/02/02 14:47:25 error: GET "/": badgateway: failed after 0s: dial unix /var/opt/gitlab/gitlab-rails/sockets/gitlab.socket: connect: no such file or directory
2018-02-02_06:47:25.68697 git.tuandai888.com @ - - [2018-02-02 14:47:25.683237091 +0800 CST] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36" 0.003579
2018-02-02_06:47:25.87230 2018/02/02 14:47:25 Send static file "/opt/gitlab/embedded/service/gitlab-rails/public/favicon.ico" ("") for GET "/favicon.ico"
2018-02-02_06:47:25.87285 git.tuandai888.com @ - - [2018-02-02 14:47:25.871579483 +0800 CST] "GET /favicon.ico HTTP/1.1" 200 5430 "http://git.tuandai888.com/" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36" 0.001192
2018-02-02_06:47:45.63429 2018/02/02 14:47:45 error: GET "/": badgateway: failed after 0s: dial unix /var/opt/gitlab/gitlab-rails/sockets/gitlab.socket: connect: no such file or directory
2018-02-02_06:47:45.63501 git.tuandai888.com @ - - [2018-02-02 14:47:45.631742962 +0800 CST] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36" 0.003081
2018-02-02_06:54:10.49117 git.tuandai888.com @ - - [2018-02-02 14:54:06.631802992 +0800 CST] "GET / HTTP/1.1" 302 105 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36" 3.859047==> /var/log/gitlab/nginx/current <====> /var/log/gitlab/nginx/error.log <====> /var/log/gitlab/nginx/gitlab_access.log <==
10.100.16.218 - - [02/Feb/2018:14:46:40 +0800] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:46:40 +0800] "GET /favicon.ico HTTP/1.1" 200 5430 "http://10.100.12.66/" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:46:40 +0800] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:46:40 +0800] "GET /favicon.ico HTTP/1.1" 200 5430 "http://10.100.12.66/" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:46:40 +0800] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:46:40 +0800] "GET /favicon.ico HTTP/1.1" 200 5430 "http://10.100.12.66/" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:47:25 +0800] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:47:25 +0800] "GET /favicon.ico HTTP/1.1" 200 5430 "http://git.tuandai888.com/" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:47:45 +0800] "GET / HTTP/1.1" 502 2916 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"
10.100.16.218 - - [02/Feb/2018:14:54:10 +0800] "GET / HTTP/1.1" 302 105 "" "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36"

安装好GitLab，开启服务，发现有502错误。这是开始寻找解决办法，各种百度。 
1.找到/var/log/gitlab/nginx中的错误日志文件，发现有如下错误/var/opt/gitlab/gitlab-rails/sockets/gitlab.socket failed (2: No such file or directory)，然后用 nc命令创建了这个socket文件，最终权限设为srwxrwxrwx，用户和组设置为git:git，但发现这个方法行不通。

2.这时我跑到GitLab的官网去寻找解决办法，https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/README.md 
ctrl+f 502 找到官方教程中说502出现的问题

Note that on a single-core server it may take up to a minute to restart Unicorn and Sidekiq. Your GitLab instance will give a 502 error until Unicorn is up again.

It is also possible to start, stop or restart individual components.

sudo gitlab-ctl restart sidekiq 
Unicorn supports zero-downtime reloads. These can be triggered as follows:

sudo gitlab-ctl hup unicorn 
Note that you cannot use a Unicorn reload to update the Ruby runtime.

尝试用上面两个命令解决，发现没有用。 
这时我怒了，不断的输入gitlab-ctl status,发现unicorn的pid一直在变大。而其他几个服务的pid没有变化。

3.这时差不多找到了问题的所在了，应该就是unicorn的问题。然后看官方教程，可以使用gitlab-ctl tail unicorn 来跟踪unicorn的状态，这时候悲催的发现原来时权限不够，chmod -R 777 /var/log/gitlab

502 Whoops, GitLab is taking too much time to respond。经搜索梳理网上几篇相同问题的解决方案，归纳原因可能如下：

1、unicorn原8080默认端口被容器中别的进程已经占用，必须调整为没用过的

2、gitlab的timeout设置过小，默认为60

从这两个原因着手，开始调整配置：

1、使用以下命令编辑gitlab配置文件：

sudo docker exec -it gitlab vim /etc/gitlab/gitlab.rb

经试验，应该修改以下配置项：

unicorn['port'] = 8888

gitlab_workhorse['auth_backend'] = "http://localhost:8888"

注意：unicorn['port']与gitlab_workhorse['auth_backend']的端口必须相同

2、调整timout时长，从60秒改为90秒

gitlab_rails['webhook_timeout'] = 90

gitlab_rails['git_timeout']=90

以上配置修改完成后，使用以下命令重启容器：

docker restart gitlab
docker logs gitlab

也可以通过以下命令进入容器，查看gitlab启动状态和动态日志：

sudo docker exec -it gitlab /bin/bash
cd /usr/bin
gitlab-ctl status
gitlab-ctl tail

3、初始镜像、容器的创建步骤是这样的：

sudo docker pull gitlab/gitlab-ce
chmod 777 /var/log/gitlab
sudo docker run --detach --hostname devops --publish 443:443 --publish 80:80 --publish 20022:22 --name gitlab --env GITLAB_OMNIBUS_CONFIG="external_url 'http://devops/'; gitlab_rails['lfs_enabled'] = true;" --restart always --volume /home/linyu/gitlab/config:/etc/gitlab --volume /home/linyu/gitlab/logs:/var/log/gitlab --volume /home/linyu/gitlab/data:/var/opt/gitlab gitlab/gitlab-ce:latest

4、也可以进入容器后，根据容器创建时映射的--volume目录，在里面修改配置，然后重启gitlab：

gitlab-ctl reconfigure
gitlab-ctl retart
gitlab-ctl status
gitlab-ctl tail