Terraform AWS Provider is upgraded to version 4.0.0 which is published on 10 February 2022.

Major changes in the release include:

• Version 4.0.0 of the AWS Provider introduces significant changes to the aws_s3_bucket resource.
• Version 4.0.0 of the AWS Provider will be the last major version to support EC2-Classic resources as AWS plans to fully retire EC2-Classic Networking. See the AWS News Blog for additional details.
• Version 4.0.0 and 4.x.x versions of the AWS Provider will be the last versions compatible with Terraform 0.12-0.15.

The reason for this change by Terraform is as follows: To help distribute the management of S3 bucket settings via independent resources, various arguments and attributes in the aws_s3_bucket resource have become read-only. Configurations dependent on these arguments should be updated to use the corresponding aws_s3_bucket_* resource. Once updated, new aws_s3_bucket_* resources should be imported into Terraform state.

So, I updated my code accordingly by following the guide here: Terraform AWS Provider Version 4 Upgrade Guide | S3 Bucket Refactor

The new working code looks like this:

resource "aws_s3_bucket" "this" {
  bucket = "${var.project}-${var.environment}-ssm-parameter-store-backups-bucket"

  tags = {
    Name        = "${var.project}-${var.environment}-ssm-parameter-store-backups-bucket"
    Environment = var.environment
  }
}

resource "aws_s3_bucket_acl" "this" {
  bucket = aws_s3_bucket.this.id
  acl    = "private"
}

resource "aws_s3_bucket_server_side_encryption_configuration" "this" {
  bucket = aws_s3_bucket.this.id

  rule {
    apply_server_side_encryption_by_default {
      kms_master_key_id = data.aws_kms_key.s3.arn
      sse_algorithm     = "aws:kms"
    }
  }
}

resource "aws_s3_bucket_lifecycle_configuration" "this" {
  bucket = aws_s3_bucket.this.id

  rule {
    id     = "backups"
    status = "Enabled"

    filter {
      prefix = "backups/"
    }

    transition {
      days          = 90
      storage_class = "GLACIER_IR"
    }

    transition {
      days          = 180
      storage_class = "DEEP_ARCHIVE"
    }

    expiration {
      days = 365
    }
  }
}

If you don't want to upgrade your Terraform AWS Provider version to 4.0.0, you can use the existing or older version by specifying it explicitly in the code as below:

terraform {
  required_version = "~> 1.0.11"
  required_providers {
    aws  = "~> 3.73.0"
  }
}

It's broken because Terraform AWS Provider was updated to version 4.0.0.

If you can't upgrade your version, maybe you could lock your AWS provider version like this:

terraform {

  required_version = "~> 0.12.31"

  required_providers {
    aws  = "~> 3.74.1"
  }
}

For Terragrunt / Terraform users

As others have mentioned, AWS Provider upgraded to 4.0. Breaking changes are delineated here (under the git 4.0 tag): GitHub | terraform-provider-aws | v4.0.0

Note the breaking changes to s3. I found 39 references of aws_s3_bucket on the page. The reality is some of us don't have time to address all the breaking changes for our current projects. I have found version 3.74.1 to be quite effective.

To restrict all your Terraform projects which are configured with Terragrunt, inside the root terragrunt.hcl file of your terragrunt repo, you can specify the following:

generate "versions" {
    path      = "versions_override.tf"
    if_exists = "overwrite_terragrunt"
    contents  = <<EOF
    terraform {
        required_providers {
        aws = {
            version = "= 3.74.1"
            source = "hashicorp/aws"
        }
        }
    }
EOF
}

In effect, Terragrunt will generate a versions_override.tf terraform config file which will define the explicit version of 3.74.1.

Quick solution: Keep your project on version 3 until you are ready to move to version 4 following the upgrade guide provided by Terraform here: Terraform AWS Provider Version 4 Upgrade Guide.

In order to do it, freeze your provider as shown below:

terraform {
   required_providers {    
    aws = {
         source = "hashicorp/aws"
         version =  "~> 3.74.2"
    }
    consul = {
      source = "hashicorp/consul"
    }
  }
  required_version = ">= 0.13"
}