Relative newbie to AWS having recently migrated servers. Everything was working fine yesterday, but today when I try to go to the site (enablie.co.uk) I receive a 504 error. Domain is registered with 123-reg, but everything else is configured in AWS (EC2, Classic LB, Route 53, AWS SSL certificate).
I also cannot SSH into the instance (again - this was fine yesterday), but I do not get an error message - it just seems to hang (so can write more text, but not actually connected as a ec2-user). Have tried with both public DNS and IP as IP seemed to work for some users, but no luck.
The only difference I have noticed with the site is that yesterday it said it was partially secure (grey exclamation mark on Chrome) and today it looks fully secure (green padlock on chrome).
I have followed the 504 steps I can, but most of them seem to require access to the instance to update various settings (e.g. disabling TCP_DEFER_ACCEPT).
I have run server diagnostics which suggests the servier is slower than average, but doesn't seem to point any obvious issues.
I assume it's an error in my configuration, but don't know where to start looking given it's a new error.
UPDATE
EC2 security groups (Launch-Wizard-3):
Inbound:
HTTP TCP 80 0.0.0.0/0
HTTP TCP 80 ::/0
SSH TCP 22 <>
HTTPS TCP 443 0.0.0.0/0
HTTPS TCP 443 ::/0
Outbound: All traffic All All 0.0.0.0/0
Loadbalancer security groups: sg-1a518b72, launch-wizard-3 (as above) launch-wizard-3 created 2017-11-17T10:51:21.644+00:00 sg-36df045e, default default VPC security group sg-bedf04d6, launch-wizard-1 launch-wizard-1 created 2017-11-16T10:45:07.276+00:00
default inbound: All traffic All All sg-36df045e (default)
Outbound: All traffic All All 0.0.0.0/0
Launch-wizard-1
Inbound:
HTTP TCP 80 0.0.0.0/0
HTTP TCP 80 ::/0
SSH TCP 22 0.0.0.0/0
Custom TCP Rule TCP 20 - 21 0.0.0.0/0
Custom TCP Rule TCP 20 - 21 ::/0
Custom TCP Rule TCP 1024 - 1048 0.0.0.0/0
Custom TCP Rule TCP 1024 - 1048 ::/0
HTTPS TCP 443 0.0.0.0/0
HTTPS TCP 443 ::/0
Outbound:
All traffic All All 0.0.0.0/0
Loadbalancer listeners: HTTP : 80 arn...7b8328a1e9739fe6 N/A N/A Default: forwarding to enabliecouk
HTTPS : 443 arn...22d722bdd042040a ELBSecurityPolicy-2016-08 Default: daff3a00-ff9e-40c2-a4b7-95499cd8b250 (ACM) Default: forwarding to enabliecouk
Healthcheck: Protocol HTTP Path / Port traffic port Healthy threshold 5 Unhealthy threshold 2 Timeout 5 Interval 30 Success codes 200
When I use ssh -v I get the following:
OpenSSH_7.5p1, LibreSSL 2.5.4 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 52: Applying options for * ssh: Could not resolve hostname enabliecouk.pem: nodename nor servname provided, or not known
UPDATE 2 Without changing any settings (though admittedly had set up the bastion host and removed unnecessary security groups from load balancer- not sure these would have made a difference as they hadn't done originally)both site and SSH were working again. However, 30 mins later I am getting the 504 error again. Is this a common problem with AWS/just bad luck or would the above changes have made it temporarily work?