Google cloud Backend service is unhealthy - 502 error

Question

I believe I have a pretty straight forward set up but I am receiving the dreaded "backend service is unhealthy" notification on my load balancer in google cloud. I will list out steps I have taken so far to provide as much info as possible as I know this could be many things.

• I created a VM in compute engine hosting wordpress
• I created an unmanaged instance group linked to that VM
• I created a load balancer (HTTPS),
• I created a HTTP backend service linking to my instance group
• I created a health check, protocol HTTP, port 80, left everything else as default
• I created a new front end HTTP, port 80, premium, reserved a new static IP address
• I pointed my domain at the new load balancer

It's worth mentioning at this point I tested I could access the web page stored on the VM without any issues.

• I then created a HTTPS front end, protocol HTTPS, port 443, premium
• I set the value of the IP to be the same as the value of the static IP I reserved when creating the HTTP front end.
• I created a new google cloud managed certificate, which was provisioned successfully

At this point I tested again and could no longer access the site and I received the 502 error on the web page.

• I created two firewall rules both set to ingress, allow-health-checks, 130.211.0.0/22 35.191.0.0/16. the only difference between the two is one is set to tcp 80 and one is set to tcp 443, I was just trying to cover off both in case. I also did try one without the other but that made no difference.

Now I am pretty stuck as I am not seeing any other potential steps I could take to resolve this issue.

I would be grateful for any potential solutions.

Cheers

Answer 1

I managed to overcome this issue by following this guide. https://www.jiyuulife.net/google-cloud-cdn-for-gcp-wordpress/ In case anyone has similar issues.

There isn't a lot of good material out there for unmanaged IG's linked to existing VM's. I found even googles documentation to be a little light on the subject. Sometimes you do want to provide load balancing to existing VM's to make use of CDN without the redundancy or expense.

I welcome additional contributions here.