In this post we are going to create an S3 bucket with a random name using the Terraform format function.

As usual we have our provider block.

# Provider 
provider "aws" {
    region = "eu-west-1"

Next we create a random string with the resource "random_id" 5 random bytes which produces 12 bits of randomness.

# Create a random string
resource "random_id" "random_string" {
  byte_length = 5

Next we create a variable for the bucket name

# Bucket name
variable "bucket_name" {
  type = string
  default = "letslearndevops"

Next we create the bucket.

The line we’re really interested in is the bucket line where we use the format function. Here we’re using %s which is used to convert to string and insert the string’s characters and %d which converts to integer number to produce decimal representation.

# Create the bucket
resource "aws_s3_bucket" "letslearndevops_bucket" {
    bucket        = format("%s-%d",var.bucket_name, random_id.random_string.dec)
    acl           = "private"

    force_destroy =  true

The result is as expected, a new S3 bucket with a random 12 character string appended to the bucket name. Centered image

Now lets add some tags to the same bucket

# Create the bucket
resource "aws_s3_bucket" "letslearndevops_bucket" {
  bucket = format("%s-%d", var.bucket_name, random_id.random_string.dec)
  acl    = "private"

  force_destroy = true

  tags = {
    String = "String"  
    Name = format("%s", var.bucket_name)
    Creation_Date  = format("%s", formatdate("DD MMM YYYY", timestamp()))

With the following result.

Centered image

Here you can see the String key is just defined as a simple "string", the Name key uses the format function to call var.bucket_name and the Creation_Date key used the timestamp function which is then formatted using the formatdate function.