This is part of an ongoing series of posts documenting the built-in interpolation functions in Terraform. For more information, check out the beginning post. In this post I am going to cover the base64decode() function. The example files are on GitHub here.
Function name: base64decode(string)
Returns: The base64decode function returns a decoded value of a base64 encoded string.
Example:
variable "base64decode" {
default = "MTIzNA=="
}
# Returns 1234
output "base64decode" {
value = "${base64decode(var.base64decode)}"
}
##############################################
# Function: base64decode
##############################################
##############################################
# Variables
##############################################
variable "base64decode" {}
##############################################
# Resources
##############################################
##############################################
# Outputs
##############################################
output "base64decode_output" {
value = "${base64decode(var.base64decode)}"
}
Run the following from the base64decode folder to get example output for a number of different cases:
#We have to encode something first
$fileContent = get-content .\terraform_image.png
$fileContentBytes = [System.Text.Encoding]::UTF8.GetBytes($fileContent)
$fileContentEncoded = [System.Convert]::ToBase64String($fileContentBytes)
terraform apply -var "base64decode=$fileContentEncoded"
#Should output ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789
terraform apply -var "base64decode=QUJDREVGR0hJSktMTU5PUFFSU1RVVldYWVowMTIzNDU2Nzg5"
#Empty string test
terraform apply -var "base64decode="
If you are being handed a string that is base64 encoded by a web service or some other data source, this is how you can transform it back into a usable string for the rest of the application. I would think primarily of parsing URL strings that are base64 encoded to assist with data transfer. If you are using the HTTP Provider to query information from a site, then you might use this function.
I have to be honest here, I didn’t really know anything about base64 encoding before I started learning about this function. In that regard, it was an excellent learning experience. If you want to know more about base64 encoding, I definitely recommend reading through the Wikipedia article.
Coming up next is base64encode().
What's New in the AzureRM Provider Version 4?
August 27, 2024
Debugging the AzureRM Provider with VSCode
August 20, 2024
State Encryption with OpenTofu
August 1, 2024
July 24, 2024