Upgrading to latest ami in ap-south-1 breaks all regional endpoint networking

[rverma-jm]

What happened:
Immediately after upgrading to latest ami, all our services were started crashing with errors like

Caused by: java.net.UnknownHostException: jm-audit-spinnaker.s3.ap-south-1.amazonaws.com

Caused by: java.net.UnknownHostException: ec2.ap-south-1.amazonaws.com

Caused by: java.net.UnknownHostException: redis.audit.internal
which points to jm-spinnaker-redis.k6r58l.ng.0001.aps1.cache.amazonaws.com

What you expected to happen:
Smooth migration

How to reproduce it (as minimally and precisely as possible):
Try depoyling app using aws sdk

Anything else we need to know?:

Environment:

• AWS Region: ap-south-1
• Instance Type(s): m5a.xlarge
• EKS Platform version (use aws eks describe-cluster --name <name> --query cluster.platformVersion): eks.1
• Kubernetes version (use aws eks describe-cluster --name <name> --query cluster.version): 1.16
• AMI Version: ami-054767c3238094200
• Kernel (e.g. uname -a): Linux ip-192-168-22-124.ap-south-1.compute.internal 4.14.173-137.229.amzn2.x86_64 Template is missing source_ami_id in the variables section #1 SMP Wed Apr 1 18:06:08 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
• Release information (run cat /etc/eks/release on a node):

BASE_AMI_ID="ami-0ab1913ead3883bb5"
BUILD_TIME="Thu Apr 23 17:45:51 UTC 2020"
BUILD_KERNEL="4.14.173-137.229.amzn2.x86_64"
ARCH="x86_64"

[cb-salaikumar]

Is there any update on this issue? We are facing similar situation as well.

[heybronson]

Taking a look at this. Is this also an issue with the latest releaseVersion (20200507)?

[ravisinha0506]

@rverma-jm Could you please verify if this issue still exists on the latest AMIs?