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Sreya Sharma
Sreya Sharma

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Day 12: Going Deeper into Terraform Functions and Validations

Day 12 was about understanding how Terraform handles time, data types, files, numbers, and validations. These topics may look small individually, but together they play a huge role in writing safe, flexible, and production-ready Terraform code.

This day helped me realize that Terraform is not just about creating resources — it’s also about controlling data and preventing mistakes before they happen.

Working with Date and Time Functions

Terraform provides functions to work with time-based values, which are useful for tagging, tracking, and automation.

Example

locals {
  created_time = timestamp()
}
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Input Validation: Preventing Wrong Values

  • Validation blocks ensure that incorrect input values are rejected before Terraform runs.
  • This avoids mistakes like passing invalid environment names and helps keep infrastructure consistent.

Numeric Functions in Terraform

Numeric functions help perform calculations inside Terraform.

Examples

max(3, 5, 7)
min(1, 2, 3)
abs(-10)
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These are useful when dealing with scaling values, limits, or thresholds.

Reading Files Using the file Function

The file function allows Terraform to read content from a file and use it inside the configuration.

Example

locals {
  policy = file("policy.json")
}

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This is very useful when attaching IAM policies, user data scripts, or configuration templates without hardcoding them.

What I Learned from Day 12

After practicing these concepts, a few things became clear:

  • Terraform can handle dynamic values easily
  • Validations catch errors early
  • File handling keeps code clean
  • Type conversions prevent runtime failures
  • Numeric functions support smarter scaling logic
  • These features add reliability to Terraform projects.

Key Takeaways from Day 12

  • Date and time functions help with tracking
  • Type conversion avoids data mismatch issues
  • File function prevents hardcoding
  • Validation blocks improve safety
  • Numeric functions support logical decisions

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