Add Terraform for async exports S3 bucket and IAM user

aws/exports.tf

@@ -0,0 +1,93 @@
+locals {
+  exports_bucket_name   = coalesce(var.exports_bucket_name, "${var.cluster_name}-exports")
+  exports_iam_user_name = "${var.cluster_name}-exports-service"
+}
+
+resource "aws_s3_bucket" "exports" {
+  bucket = local.exports_bucket_name
+}
+
+resource "aws_s3_bucket_server_side_encryption_configuration" "exports" {
+  bucket = aws_s3_bucket.exports.id
+  rule {
+    apply_server_side_encryption_by_default {
+      sse_algorithm = "AES256"
+    }
+  }
+}
+
+# Fully private — exports are never served directly to browsers.
+resource "aws_s3_bucket_public_access_block" "exports" {
+  bucket                  = aws_s3_bucket.exports.id
+  block_public_acls       = true
+  block_public_policy     = true
+  ignore_public_acls      = true
+  restrict_public_buckets = true
+}
+
+# No S3 lifecycle rule — Opal's cleanup cron is the single authority.
+# An S3 rule running independently would delete files without clearing
+# result.objectKey in Postgres, causing /download to return 404 instead
+# of the expected 410 Gone.
+
+resource "aws_s3_bucket_policy" "exports" {
+  bucket = aws_s3_bucket.exports.id
+
+  policy = jsonencode({
+    Version = "2012-10-17"
+    Statement = [
+      {
+        Sid       = "DenyInsecureTransport"
+        Effect    = "Deny"
+        Principal = "*"
+        Action    = "s3:*"
+        Resource = [
+          aws_s3_bucket.exports.arn,
+          "${aws_s3_bucket.exports.arn}/*"
+        ]
+        Condition = {
+          Bool = { "aws:SecureTransport" = "false" }
+        }
+      }
+    ]
+  })
+
+  depends_on = [aws_s3_bucket_public_access_block.exports]
+}
+
+# IAM user — scoped read/write/delete for the Opal task-workers service account.
+resource "aws_iam_user" "exports" {
+  name = local.exports_iam_user_name
+
+  lifecycle {
+    ignore_changes = [tags, tags_all]
+  }
+}
+
+data "aws_iam_policy_document" "exports" {
+  statement {
+    effect = "Allow"
+    actions = [
+      "s3:GetObject",
+      "s3:PutObject",
+      "s3:DeleteObject",
+    ]
+    resources = ["${aws_s3_bucket.exports.arn}/*"]
+  }
+
+  statement {
+    effect    = "Allow"
+    actions   = ["s3:ListBucket"]
+    resources = [aws_s3_bucket.exports.arn]
+  }
+}
+
+resource "aws_iam_policy" "exports" {
+  name   = "${local.exports_iam_user_name}-access"
+  policy = data.aws_iam_policy_document.exports.json
+}
+
+resource "aws_iam_user_policy_attachment" "exports" {
+  user       = aws_iam_user.exports.name
+  policy_arn = aws_iam_policy.exports.arn
+}

aws/outputs.tf

@@ -18,3 +18,13 @@ output "rds_password" {
   value       = random_password.password.result
   sensitive   = true
 }
+
+output "exports_bucket_name" {
+  description = "S3 bucket name for Opal async exports."
+  value       = aws_s3_bucket.exports.id
+}
+
+output "exports_iam_user_name" {
+  description = "IAM user with scoped access to the exports bucket. Generate an access key for this user (`aws iam create-access-key --user-name <name>`) and paste it into KOTS or Helm. See https://docs.opal.dev/docs/configure-async-exports-storage."
+  value       = aws_iam_user.exports.name
+}

aws/variables.tf

@@ -31,3 +31,8 @@ variable "db_instance_class" {
   default     = "db.m6i.large"
   description = "DB instance class"
 }
+
+variable "exports_bucket_name" {
+  default     = ""
+  description = "S3 bucket name for Opal async exports (must be globally unique). Defaults to <cluster_name>-exports."
+}