Cloud Formation — Troubleshooting

June Chung
Nov 10, 2020

When your instance failes to create
— Because they failed to create specific resources (security group, route53)
— Because the success health check signal didn’t come through for a certain time → This doesn’t give you much info about error
(Mostly because of Metadata(cfn-init) or UserData)

Then How should we Troubleshoot?
* Turn Off the “roll back function
- So we can go into the instance to troubleshoot
→ ‘Stack Creation Option’ : Rollback — disable (When launching template)

Then SSH into instance and Check — Metadata, Userdata, etc
* /var/log/cfn-init.log
* Check User Data Script : cat /var/lib/cloud/instance/scripts/part-001