502 Server Error after setting up Google Cloud Load Balancing

zlaczo 2020-11-19 12:51:20 UTC #1

Keywords: PrestaShop - Google Cloud Platform - Technical issue - Secure Connections (SSL/HTTPS)
bnsupport ID: 19d45d7d-ee9e-edf6-a209-23149bd5abee
Description:
Hi,

I sat up the load balancing according to this article:
https://docs.bitnami.com/google-templates/how-to/configure-lb-ssl-google-templates/#step-6-point-your-domain-name-to-the-load-balancer-s-ip-address

Now, when I try to load my site I get an 502 Server Error.
What could be the issue?

Thanks,
Zoltan

jota 2020-11-20 10:00:13 UTC #2

Hi @zlaczo,

It seems Apache is working and it's redirecting to your domain

$ curl -LI 34.91.218.162
HTTP/1.1 302 Found
Date: Fri, 20 Nov 2020 09:58:13 GMT
Server: Apache/2.4.46 (Unix) OpenSSL/1.1.1d
X-Powered-By: PHP/7.2.33
Location: http://www.deco-shades.com/
Content-Type: text/html; charset=utf-8

HTTP/1.1 502 Bad Gateway
Content-Type: text/html; charset=UTF-8
Referrer-Policy: no-referrer
Content-Length: 332
Date: Fri, 20 Nov 2020 09:58:13 GMT

However, the domain name is pointing to 2 different IP addresses depending on if you are using www or not.

https://www.whatsmydns.net/#A/deco-shades.com
https://www.whatsmydns.net/#A/www.deco-shades.com

Could you please ensure you configure your DNS properly?

zlaczo 2020-11-20 12:00:40 UTC #3

Hi @jota

The fact that only www subdomain is directed to the load balancer should not be the cause of this issue as www. should load properly. I updated the DNS to point the non www as well but the same issue still persists.

Any other idea that could cause the 502 server error?

In the error log I see this:
[authz_core:error] [pid 1409:tid 140631565256448] [client ] AH01630: client denied by server configuration: /opt/bitnami/prestashop/config/getuser

Also, on the load balancer, I see an unhealthy service

zlaczo 2020-11-20 12:04:06 UTC #4

@jota

Actually, the IP address from your comment $ curl -LI 34.91.218.162 is the address of the instance but the load balancer's IP is 35.214.208.228.
Do you think I should change this IP to the load balancer's IP?
The domain name is directed towards the load balancer's IP and not the instance IP.

If yes, how can I update it?

jota 2020-11-23 08:02:32 UTC #5

Hi @zlaczo,

I just accessed your site using the IP of the machine and the domain name. The domain is pointing to another IP so I understand it's using the load balancer, right?

Could you please let us know how you resolved the error?

Thanks

zlaczo 2020-11-23 08:10:20 UTC #6

Hi @jota,

No, unfortunately I couldn't fix the issue with the load balancer. I just pointed back the domain to the "old" website until I figure out how to fix it.
This is the load balancer IP (35.214.208.228) which is still connected to the instance and gives a 502 error.

jota 2020-11-23 08:35:14 UTC #7

Thanks for the info @zlaczo,

However, the new website works properly when using the IP address (34.91.218.162) or a fake domain (34.91.218.162.nip.io).

I just noticed that the application is redirecting all the requests to the IP address of the instance

$ curl -LI 34.91.218.162.nip.io
HTTP/1.1 302 Found
Date: Mon, 23 Nov 2020 08:32:16 GMT
Server: Apache/2.4.46 (Unix) OpenSSL/1.1.1d
X-Powered-By: PHP/7.2.33
Location: http://34.91.218.162/
Content-Type: text/html; charset=utf-8

That can be the issue with the load balancer. Can you configure the application with your domain and then point the load balancer to the new instance again?

https://docs.bitnami.com/google/apps/prestashop/administration/update-ip-hostname/

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