Convert AWS EC2 Instance HCL to JSON

AWS EC2 Instance Configuration

The aws_instance resource is one of the most common Terraform resources. Its HCL-to-JSON conversion demonstrates how resource blocks, nested blocks, maps, and string values translate.

Complete EC2 HCL Example

resource "aws_instance" "web" {
  ami                    = "ami-0c55b159cbfafe1f0"
  instance_type          = "t3.micro"
  key_name               = "my-key-pair"
  vpc_security_group_ids = ["sg-abc123"]
  subnet_id              = "subnet-xyz789"

  tags = {
    Name        = "web-server"
    Environment = "production"
  }

  root_block_device {
    volume_size = 20
    volume_type = "gp3"
    encrypted   = true
  }

  metadata_options {
    http_endpoint = "enabled"
    http_tokens   = "required"
  }
}

JSON Equivalent

In Terraform's JSON syntax, the three-level nesting (resource > resource type > resource name) wraps the configuration body. Lists like vpc_security_group_ids remain as JSON arrays. Nested blocks like root_block_device and metadata_options become nested JSON objects.

Important Considerations

• Tags map: The tags attribute is a map, not a block, so it uses = assignment in HCL and becomes a regular JSON object.
• Security group IDs: List values maintain their array structure in JSON.
• Nested blocks: root_block_device and metadata_options are blocks (no = sign), becoming nested objects.
• IMDSv2: The metadata_options block with http_tokens = "required" enforces IMDSv2, a security best practice.