Terraform for Ultra-Fast EV Charging Backend Infrastructure

resource "aws_apigatewayv2_api" "ocpp" {
  name                       = "ocpp-csms"
  protocol_type              = "WEBSOCKET"
  route_selection_expression = "$request.body.action"
}
 
resource "aws_apigatewayv2_route" "boot" {
  api_id    = aws_apigatewayv2_api.ocpp.id
  route_key = "BootNotification"
  target    = "integrations/${aws_apigatewayv2_integration.ocpp.id}"
}
 
resource "aws_apigatewayv2_route" "stop" {
  api_id    = aws_apigatewayv2_api.ocpp.id
  route_key = "StopTransaction"
  target    = "integrations/${aws_apigatewayv2_integration.ocpp.id}"
}

resource "aws_dynamodb_table" "sessions" {
  name         = "ev_sessions"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "session_id"
 
  attribute {
    name = "session_id"
    type = "S"
  }
  attribute {
    name = "charger_id"
    type = "S"
  }
 
  global_secondary_index {
    name            = "by-charger"
    hash_key        = "charger_id"
    projection_type = "ALL"
  }
 
  stream_enabled   = true
  stream_view_type = "NEW_AND_OLD_IMAGES"
 
  point_in_time_recovery { enabled = true }
}

resource "aws_pipes_pipe" "session_to_billing" {
  name        = "session-to-billing"
  role_arn    = aws_iam_role.pipes.arn
  source      = aws_dynamodb_table.sessions.stream_arn
  target      = aws_lambda_function.billing.arn
 
  source_parameters {
    dynamodb_stream_parameters {
      starting_position = "LATEST"
      batch_size        = 10
    }
    filter_criteria {
      filter {
        pattern = jsonencode({
          eventName = ["MODIFY"]
          dynamodb  = { NewImage = { state = { S = ["completed"] } } }
        })
      }
    }
  }
}

resource "aws_timestreamwrite_table" "grid" {
  database_name = aws_timestreamwrite_database.ev.database_name
  table_name    = "grid_metrics"
 
  retention_properties {
    memory_store_retention_period_in_hours  = 24
    magnetic_store_retention_period_in_days = 730
  }
}
 
resource "aws_grafana_workspace" "ev" {
  account_access_type      = "CURRENT_ACCOUNT"
  authentication_providers = ["AWS_SSO"]
  permission_type          = "SERVICE_MANAGED"
  data_sources             = ["TIMESTREAM", "CLOUDWATCH"]
  role_arn                 = aws_iam_role.grafana.arn
}

resource "aws_appsync_graphql_api" "availability" {
  name                = "ev-availability"
  authentication_type = "API_KEY"
  schema              = file("${path.module}/schema.graphql")
}
 
resource "aws_appsync_datasource" "sessions" {
  api_id           = aws_appsync_graphql_api.availability.id
  name             = "sessions"
  service_role_arn = aws_iam_role.appsync.arn
  type             = "AMAZON_DYNAMODB"
 
  dynamodb_config {
    table_name = aws_dynamodb_table.sessions.name
  }
}