Terraform Base64 Encode: A Comprehensive Guide

Estimated reading time: 6 minutes

Last updated on November 8th, 2024 at 02:16 pm

Terraform is the popular infrastructure as a code (IaC) tool for managing and provisioning the infrastructure. Base64 encoding is important in a cloud environment for managing the configuration, secrets, and even the resource identifier.

Terraform offers native support for the Base64 encoding, enabling you to encode and decode the data directly in your configurations.

In this guide, we’ll explore the Terraform Base64 Encode function with practical examples, best practices, and troubleshooting tips.

What is Base64 Encoding in Terraform?

Overview of Base64 Encoding

Base64 encoding is a technique for converting binary data such as images, files, or any non-textual content into a text string that uses 64 ASCII characters.

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Base64 Encoding Character Set

• Uppercase letters (A-Z)
• Lowercase letters (a-z)
• Numbers (0-9)
• Two additional symbols (+ and /)

The main goal of using the Base64 encoding is to make the data readable and transferable to other systems that may not accept or handle the binary data. ( e.g: URL, a text-based data stream )

In summary, Base64 encoding takes the binary input and output into the 6-bit segment that is later mapped to a 64-character set. This makes it more portable and corruption-free when transmitted.

Role of Base64 Encoding in Terraform

The Terraform Base64 Encode method is mainly used to secure sensitive data or encode the data to ensure compatibility with the API. Terraform Base64 Encode allows to management of the cloud resource and integration with the external system.

Let’s understand its importance and usage scenarios:

Why Use Base64 Encoding in Terraform?

Obfuscating Sensitive Data

Base64 is not the secure way to encrypt data, but it is often used to obfuscate sensitive data such as API tokens, SSH keys, or other credentials information. Obfuscation makes it harder for someone to find sensitive data.

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Ensure Data Compatibility

Sometimes cloud providers and external APIs require the data in Base64 format.

Terraform base64encode function allows you to natively convert the strings into the required format to ensure the data is compatible when transferred.

Binary Data Embedding

Terraform Base64 Encode can be used for the binary data file such as certificates or the private keys directly in your configuration code. It makes your code more portable and easy to manage within the team.

How to Use Terraform Base64 Encode Function

Terraform provides a built-in base64encode function that converts a string to its Base64 equivalent.

Syntax and Parameters

The syntax for the base64encode function is straightforward:

base64encode(<input_string>)

Here the <input_string> can be the plain text you want to encode.

Practical Examples of Terraform Base64 Encode

Let’s look at the practical example where you need to encode the sensitive API token before storing to cloud provider configuration:

variable "api_token" {
  description = "The plain text API token"
  type        = string
  default     = "terraform-base64-encode"
}

output "encoded_token" {
  value = base64encode(var.api_token)
}

Now you run terraform apply, the output will show the Base64 encoded version of your token:

encoded_token = "dGVycmFmb3JtLWJhc2U2NC1lbmNvZGU="

Since the encoded value is obfuscated it can be safely passed to other systems or stored in a file.

Common Mistakes to Avoid With Base64 Encoding

One common mistake seen by others is trying to encode a non-string data type such as a list or map without first converting to a string.

Ensure that your input is always a string before passing it to base64encode():

value = base64encode(join(",", ["value1", "value2", "value3"]))

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Decoding Base64 in Terraform

Terraform also supports the decoding. There are scenarios where you might need to decode Base64 strings in Terraform.

The Base64 Decode Function

The base64decode function is the opposite to base64encode. It takes a Base64 encoded string and converts it back to plain text.

output "decoded_token" {
  value = base64decode("dGVycmFmb3JtLWJhc2U2NC1lbmNvZGU=")
}

The output will be:

decoded_token = "terraform-base64-encode"

Use Cases for Decoding

Decoding is useful when you retrieve data from an external system or cloud provider.

Once the data is retrieved you can use the decode function and use that value in your Terraform configuration such as runtime values.

Best Practices for Terraform Base64 Encode

Security Considerations

As we talked about earlier Base64 encoding can obfuscate sensitive data but that is not the secure encryption method. Base64 encoded data can be easily decoded so be sure what to store and transfer.

If you want to store sensitive data such as passwords or API keys, consider opt-in for encrypting the data using the secure method and storing it in the HarshiCorp Value or AWS Secret Manager.

Must read: Terraform Where to Store Secrets: Best Practices and Solutions

Performance Impact

Usually, encoding and decoding are not resource-intensive and are considered lightweight. if you planning to encode/decode the large and long configuration files, that can impact the performance.

Use encode and decode carefully and avoid unnecessary operations in your Terraform configurations.

Troubleshooting Common Issues: Terraform Base64 Encode

Encoding Errors and Their Solutions

If you face errors during encoding, verify that the input is a valid string. You might also need to sanitize or trim your input data before encoding.

value = base64encode(trimspace(var.input_data))

Debugging Tips

For debugging you can use Terraform’s built-in terraform console to test functions interactively:

$ terraform console

> base64encode("test-string")
> "dGVzdC1zdHJpbmc="

> base64encode("terraform-base64-encode")
> "dGVycmFmb3JtLWJhc2U2NC1lbmNvZGU="

This lets you validate your configurations and identify any errors.

Conclusion

Key Takeaways

Terraform Base64 Encode and Decode are important when dealing with configuration, secrets, or API integrations.

Base64 encoding is a simple yet powerful way to encode data but it should be used with care, especially when handling sensitive data.

Further Reading and Resources

Terraform XML Encode: A Comprehensive Guide

Terraform Nonsensitive: 4 Essential Tips for Safe Data Handling

How to Terraform Generate Password: Easy Guide

Terraform Where to Store Secrets: Best Practices and Solutions