Gitlab error 502 when loading... is that normal? - ruby-on-rails

Question

When I restart my gitlab server with sudo gitlab-ctl restart (Debian Jessie), while the server is loading, I get the 502 error, instead of the "Deploying" page. Then everything works fine. I don't understand why this happens.
Please be aware that this appears only when loading, then everything works fine. I'm not satisfied because I used to get the better "Deploying" page.
This started happening after I configured my gitlab to work through gitlab-workhorse to go through my apache server proxy (prior to that I had huge problems with web interface communication. Snapshots downloads didn't work, but now everything is fine). Before fixing that, I used to proxy gitlab's nginx.
The configuration I currently use for apache is the following, which complies to the standard configuration of Gitlab:
<VirtualHost *:443>
ServerName git.example.com
ServerSignature Off
ProxyPreserveHost On
# Ensure that encoded slashes are not decoded but left in their encoded state.
# http://doc.gitlab.com/ce/api/projects.html#get-single-project
AllowEncodedSlashes NoDecode
<Location />
# New authorization commands for apache 2.4 and up
# http://httpd.apache.org/docs/2.4/upgrading.html#access
Require all granted
#Allow forwarding to gitlab-workhorse
ProxyPassReverse http://127.0.0.1:8283
ProxyPassReverse https://git.example.com/
</Location>
RewriteEngine on
#Don't escape encoded characters in api requests
RewriteCond %{REQUEST_URI} ^/api/v3/.*
RewriteRule .* http://127.0.0.1:8283%{REQUEST_URI} [P,QSA,NE]
#Forward all requests to gitlab-workhorse except existing files like error documents
RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f [OR]
RewriteCond %{REQUEST_URI} ^/uploads/.*
RewriteRule .* http://127.0.0.1:8283%{REQUEST_URI} [P,QSA]
# needed for downloading attachments
DocumentRoot /opt/gitlab/embedded/service/gitlab-rails/public
#Set up apache error documents, if back end goes down (i.e. 503 error) then a maintenance/deploy page is thrown up.
ErrorDocument 404 /404.html
ErrorDocument 422 /422.html
ErrorDocument 500 /500.html
ErrorDocument 503 /deploy.html
#... ssl config
RequestHeader set X_FORWARDED_PROTO 'https'
RequestHeader set X-Forwarded-Ssl on
LogFormat "%{X-Forwarded-For}i %l %u %t \"%r\" %>s %b" common_forwarded
ErrorLog /home/myuser/logs/gitlab_error.log
CustomLog /home/myuser/logs/gitlab_forwarded.log common_forwarded
CustomLog /home/myuser/logs/gitlab_access.log combined env=!dontlog
CustomLog /home/myuser/logs/gitlab.log combined
</VirtualHost>
The only configuration I changed, is my /etc/gitlab/gitlab.rb, which I did for the proxy to work.
external_url 'https://git.example.com'
nginx['enable'] = false
web_server['external_users'] = ['www-data']
gitlab_workhorse['listen_network'] = "tcp"
gitlab_workhorse['listen_addr'] = "127.0.0.1:8283"
What is it that I'm doing wrong to get that 502 error instead of the nice "Deploying" page that I used to get before doing these changes?
If you require any additional information, please ask.

Answer 1

Usually I see this page after gitlab-ctl start.
My Solution is
sudo gitlab-ctl start
sudo gitlab-ctl reconfigure
refresh browser :)

Answer 2

Well, technically this is the way it should work, it's a 502 error after all. If you want to show the deploy page there is a manual way to set it up before each restart:
gitlab-ctl deploy-page up
Wait a minute and then again:
gitlab-ctl deploy-page down
Otherwise you can add to your Apache config:
ErrorDocument 502 /deploy.html
which will show the deploy page every time a 502 error occurs.

Answer 3

config server firewall to allow http and https:
sudo ufw enable
sudo ufw allow http
sudo ufw allow https
sudo ufw allow OpenSSH
sudo ufw status
Output
Status: active
To Action From
-- ------ ----
OpenSSH ALLOW Anywhere
80/tcp ALLOW Anywhere
443/tcp ALLOW Anywhere
OpenSSH (v6) ALLOW Anywhere (v6)
80/tcp (v6) ALLOW Anywhere (v6)
443/tcp (v6) ALLOW Anywhere (v6)