Convert Terraform Data Sources to JSON

Terraform Data Sources

Data sources allow Terraform to read information from existing infrastructure or external services. They use the data block type and are read-only.

HCL Data Source Examples

data "aws_ami" "ubuntu" {
  most_recent = true
  owners      = ["099720109477"]

  filter {
    name   = "name"
    values = ["ubuntu/images/hvm-ssd/ubuntu-jammy-22.04-amd64-server-*"]
  }

  filter {
    name   = "virtualization-type"
    values = ["hvm"]
  }
}

data "aws_availability_zones" "available" {
  state = "available"
}

data "aws_iam_policy_document" "assume_role" {
  statement {
    actions = ["sts:AssumeRole"]

    principals {
      type        = "Service"
      identifiers = ["ec2.amazonaws.com"]
    }
  }
}

JSON Structure

Data sources follow the same nesting pattern as resources: data > data source type > data source name > attributes.

{
  "data": {
    "aws_ami": {
      "ubuntu": {
        "most_recent": true,
        "owners": ["099720109477"],
        "filter": {
          "name": "name",
          "values": ["ubuntu/images/..."]
        }
      }
    }
  }
}

Multiple Filter Blocks

When multiple filter blocks appear, they should be collected into a JSON array. Each filter block becomes an object in the array.

IAM Policy Documents

The aws_iam_policy_document data source is one of the most complex, with nested statement, principals, condition, and not_actions blocks. The JSON representation mirrors this nesting faithfully.

Data Source References

Data source values are referenced as data.aws_ami.ubuntu.id in HCL. These expressions become strings in JSON output.