payments-dashboard/terraform/lambda_boundary.tf

# Per-workload Lambda permissions boundary. Created on the first (bootstrap)
# apply. The scoped apply role denies iam:CreatePolicy / CreatePolicyVersion,
# so later edits to this document need the hcptf-bootstrap window.

data "aws_iam_policy_document" "lambda_boundary" {
  # checkov:skip=CKV_AWS_111: AWS requires Resource=* for logs:DescribeLogGroups, xray Put*, and EC2 ENI lifecycle used by VPC Lambdas. Secrets, table, CMK, buckets, DLQ, and invoke are ARN-pinned.
  statement {
    sid    = "CloudWatchLogsWrite"
    effect = "Allow"
    actions = [
      "logs:CreateLogGroup",
      "logs:CreateLogStream",
      "logs:PutLogEvents",
      "logs:DescribeLogStreams",
    ]
    resources = [
      "arn:aws:logs:${var.aws_region}:${local.account_id}:log-group:/aws/lambda*",
    ]
  }

  statement {
    sid       = "CloudWatchLogsDescribe"
    effect    = "Allow"
    actions   = ["logs:DescribeLogGroups"]
    resources = ["*"]
  }

  statement {
    sid    = "XRay"
    effect = "Allow"
    actions = [
      "xray:PutTraceSegments",
      "xray:PutTelemetryRecords",
    ]
    resources = ["*"]
  }

  statement {
    sid    = "Ec2Eni"
    effect = "Allow"
    actions = [
      "ec2:CreateNetworkInterface",
      "ec2:DescribeNetworkInterfaces",
      "ec2:DeleteNetworkInterface",
      "ec2:DescribeSubnets",
      "ec2:DescribeSecurityGroups",
      "ec2:DescribeVpcs",
    ]
    resources = ["*"]
  }

  statement {
    sid    = "PaymentsSecrets"
    effect = "Allow"
    actions = [
      "secretsmanager:GetSecretValue",
    ]
    resources = [for arn in local.secret_arns : arn]
  }

  statement {
    sid    = "PaymentsDynamoDB"
    effect = "Allow"
    actions = [
      "dynamodb:GetItem",
      "dynamodb:PutItem",
      "dynamodb:UpdateItem",
      "dynamodb:DeleteItem",
      "dynamodb:Query",
      "dynamodb:Scan",
      "dynamodb:BatchGetItem",
      "dynamodb:BatchWriteItem",
      "dynamodb:DescribeTable",
      "dynamodb:ConditionCheckItem",
    ]
    resources = [
      "arn:aws:dynamodb:${var.aws_region}:${local.account_id}:table/${local.table_name}",
      "arn:aws:dynamodb:${var.aws_region}:${local.account_id}:table/${local.table_name}/*",
    ]
  }

  statement {
    sid    = "PaymentsCmk"
    effect = "Allow"
    actions = [
      "kms:Decrypt",
      "kms:GenerateDataKey",
      "kms:DescribeKey",
    ]
    resources = [local.dynamodb_cmk_arn]

    condition {
      test     = "StringEquals"
      variable = "kms:ViaService"
      values   = ["dynamodb.${var.aws_region}.amazonaws.com"]
    }
  }

  statement {
    sid    = "PaymentsCsvRead"
    effect = "Allow"
    actions = [
      "s3:GetObject",
      "s3:GetObjectVersion",
    ]
    resources = ["arn:aws:s3:::${local.csv_bucket_name}/*"]
  }

  statement {
    sid    = "PaymentsBoaRawPut"
    effect = "Allow"
    actions = [
      "s3:PutObject",
    ]
    resources = ["arn:aws:s3:::${local.boa_raw_bucket_name}/*"]
  }

  statement {
    sid    = "PaymentsDlqSend"
    effect = "Allow"
    actions = [
      "sqs:SendMessage",
    ]
    resources = [
      "arn:aws:sqs:${var.aws_region}:${local.account_id}:payments-processPaymentCsv-async-dlq",
    ]
  }

  statement {
    sid    = "PaymentsInvokeExpenseProcessor"
    effect = "Allow"
    actions = [
      "lambda:InvokeFunction",
    ]
    resources = [
      "arn:aws:lambda:${var.aws_region}:${local.account_id}:function:payments-expenseProcessor",
    ]
  }
}

resource "aws_iam_policy" "lambda_boundary" {
  # checkov:skip=CKV_AWS_111: AWS requires Resource=* for logs:DescribeLogGroups, xray Put*, and EC2 ENI lifecycle used by VPC Lambdas. Secrets, table, CMK, buckets, DLQ, and invoke are ARN-pinned.
  name        = "payments-dashboard-lambda-boundary"
  path        = "/tf-managed/"
  description = "Per-workload Lambda permissions boundary for payments-dashboard (PLAT-79)."
  policy      = data.aws_iam_policy_document.lambda_boundary.json
}