Shallow merge() function prevents nested configuration composition

5/10 Medium

Terraform's merge() function only performs shallow merging, not deep merging of nested maps and objects. This prevents clean composition of default configurations with user-supplied overrides and makes merging multi-level data structures awkward.

Terraform HCL

Sources

https://terramate.io/rethinking-iac/10-biggest-pitfalls-of-terraform/?gi=c4b13e5ca8ee
https://jonathan.bergknoff.com/journal/terraform-pain-points/
https://terramate.io/rethinking-iac/10-biggest-pitfalls-of-terraform/

Collection History

Query: “What are the most common pain points with Terraform for developers in 2025?”3/29/2026

In Terraform, merging or combining maps and objects at multiple levels, also known as 'deep merging', is not allowed. This limitation makes it hard to merge default configurations with user inputs.

Created: 3/29/2026Updated: 3/29/2026