Using Encoding Functions

1. Using base64encode and base64decode Functions

Function	Signature	Description	Example
base64encode	`base64encode(string)`	Encodes a string into base64 format	`base64encode("hello world")`
base64decode	`base64decode(string)`	Decodes a base64-encoded string back to original	`base64decode("aGVsbG8gd29ybGQ=")`

Example: Encoding and Decoding a Secret

resource "aws_ssm_parameter" "secret" {
  name  = "my-secret"
  type  = "SecureString"
  value = base64encode("my-sensitive-data")
}

Example: Decoding a Base64 Value

output "decoded_secret" {
  value = base64decode("aHR0cHM6Ly93d3cueW91dHViZS5jb20v")
}

2. Using jsonencode and jsondecode Functions

Function	Signature	Description	Example
jsonencode	`jsonencode(value)`	Encodes a value into a JSON string	`jsonencode({ name = "example" port = 8080 })`
jsondecode	`jsondecode(string)`	Decodes a JSON string into a Terraform value	`jsondecode("{\"name\": \"example\", \"port\": 8080}")`

Example: Using jsonencode to format a map

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  tags = jsonencode({
    Name = "ExampleBucket"
    Environment = "Production"
  })
}

Example: Using jsondecode to parse a JSON string

variable "bucket_tags" {
  type = string
  default = "{\"Name\": \"ExampleBucket\", \"Environment\": \"Production\"}"
}

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  tags = jsondecode(var.bucket_tags)
}

3. Using yamlencode and yamldecode Functions

Function	Signature	Description	Example
yamlencode	`yamlencode(any)`	Encodes a value into a YAML string	`yamlencode({ name = "example" port = 8080 })`
yamldecode	`yamldecode(string)`	Decodes a YAML string into a value	`yamldecode("name: example\nport: 8080")`

Example: Using yamlencode to format data

resource "local_file" "config" {
  content = yamlencode({
    database = {
      host = "localhost"
      port = 5432
    }
  })
  filename = "config.yaml"
}

Example: Using yamldecode to parse data

data "local_file" "config" {
  filename = "config.yaml"
}

locals {
  parsed_config = yamldecode(data.local_file.config.content)
}

4. Using csvdecode Function

Function	Signature	Description	Examples
csvdecode	`csvdecode(string)`	Decodes a CSV-formatted string into a list of lists of strings.	`csvdecode("name,age\nJohn,30\nJane,25")`

Example: Decoding CSV Data

locals {
  csv_data = "id,name,role\n1,John,Developer\n2,Jane,Designer"
  decoded = csvdecode(local.csv_data)
}

output "first_row" {
  value = local.decoded[0]
}

Note: The csvdecode function expects a valid CSV string and will throw an error if the format is invalid.

5. Using urlencode Function

Function	Signature	Description	Example
urlencode	`urlencode(string)`	Encodes a string for use in a URL, replacing special characters with their percent-encoded equivalents.	`urlencode("hello world") = "hello%20world"`

Example: Encoding a URL Parameter

resource "aws_s3_object" "my_object" {
  bucket = "my-bucket"
  key    = "${urlencode(var.object_name)}"
}

Note: The urlencode function is particularly useful when constructing URLs dynamically, ensuring that special characters like spaces or ampersands are properly encoded to avoid URL parsing errors.

6. Using textencodebase64 and textdecodebase64 Functions

Function	Description	Example
textencodebase64	Encodes a string into Base64 format.	`textencodebase64("Hello, World!")`
textdecodebase64	Decodes a Base64-encoded string back to its original form.	`textdecodebase64("SGVsbG8sIFdvcmxkIQ==")`

Example: Encoding and Decoding with Base64

resource "aws_s3_object" "encoded_data" {
  bucket = aws_s3_bucket.example.id
  key    = "data.txt"
  content = textencodebase64("Sensitive data to encode")
}

Example: Decoding Base64 Data

data "aws_s3_object" "decoded_data" {
  bucket = aws_s3_bucket.example.id
  key    = "data.txt"
  content = textdecodebase64(aws_s3_object.encoded_data.content)
}

7. Using base64gzip Function

Function	Signature	Description	Example
base64gzip	`base64gzip(string)`	Encodes a string in base64 after compressing it with gzip.	`base64gzip("Hello, World!")`

Example: Encoding and Decoding with base64gzip

data "external" "decode_base64gzip" {
  program = ["sh", "-c", "echo '${base64gzip("Hello, World!")}' | base64 -d | gzip -dc"]
}

Note: The base64gzip function is useful for reducing the size of large strings or configuration data, particularly when storing them in variables or as part of a larger payload.

8. Using md5 and sha256 Functions

Function	Description	Example	Notes
md5()	Calculates the MD5 hash of a given string	`md5("hello world")`	Returns a 32-character hexadecimal string
sha256()	Calculates the SHA-256 hash of a given string	`sha256("hello world")`	Returns a 64-character hexadecimal string

Example: Using md5() in a variable

variable &#34;input_string&#34; {
  type = string
  default = &#34;hello world&#34;
}

output &#34;md5_hash&#34; {
  value = md5(var.input_string)
}

Example: Using sha256() in a resource

resource &#34;aws_s3_bucket&#34; &#34;example&#34; {
  bucket = &#34;example-bucket-&#34; + sha256(var.environment)
}

Note: These functions are deterministic and can be used for generating consistent identifiers or checksums. They are not cryptographically secure for security-sensitive applications.

9. Using uuid and uuidv5 Functions

Function	Description	Example	Notes
uuid()	Generates a random UUID version 4 (RFC 4122).	`resource "aws_s3_bucket" "example" { bucket = "my-bucket-${uuid()}" }`	Useful for generating unique identifiers for resources.
uuidv5()	Generates a UUID version 5 (SHA-1 namespace) based on input.	`resource "aws_s3_bucket" "example" { bucket = "my-bucket-${uuidv5("ns:example", "name")}" }`	Ensures deterministic UUIDs for consistent resource naming.

10. Using bcrypt Function

Function	Signature	Description	Notes
bcrypt	`bcrypt(password, cost)`	Hashes a password using the bcrypt algorithm	Useful for securely storing passwords in configuration files or state files.

Example: Hashing a Password with bcrypt

resource "aws_iam_user" "user" {
  name = "example-user"
}

resource "aws_iam_user_login_profile" "user_profile" {
  user = aws_iam_user.user.name
  password = bcrypt("mySecretPassword123", 12)
  password_reset_required = false
}

Note: The bcrypt function is available in Terraform v0.12.0 and later.