Terraform gotchas

Florian Dambrine - Senior Devops Engineer @GumGum

#1 - decouple tfstate files

#2 - leverage terraform_remote_state

#3 - re-expose module outputs if you want to access them with datasources

#4 - Module dependencies / Using outputs as module inputs

#5 - value of 'count' can not be computed

https://github.com/hashicorp/terraform/issues/10857

$ terraform plan
Error configuring: 1 error(s) occurred:

* aws_sns_topic_subscription.example: value of 'count' cannot be computed

#6 - count can be evil (forces new resources)