Class: Assistant::SqlBroker

Inherits:
Object
  • Object
show all
Defined in:
app/services/assistant/sql_broker.rb

Overview

Single execution broker for read-only analytics SQL. Enforces:

  • Role-based object access
  • Sensitive object blocking
  • Sensitive column redaction
  • Statement timeout + row caps
  • Audit logging

Constant Summary collapse

READ_ONLY_PREFIXES = 
%w[SELECT SHOW WITH EXPLAIN SET].freeze
DEFAULT_STATEMENT_TIMEOUT_MS = 
8_000

Instance Method Summary collapse

Constructor Details

#initialize(connection_class_name:, service_key:, role:, tool_name:, allowed_objects: nil, audit_context: {}) ⇒ SqlBroker

Returns a new instance of SqlBroker.

Parameters:

  • allowed_objects (Set, nil) (defaults to: nil) —

    Domain-resolved set of allowed view/table names.
    nil = unrestricted (admin). Falls back to DataPolicy.allowed_objects(role) if not provided.



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# File 'app/services/assistant/sql_broker.rb', line 18

def initialize(connection_class_name:, service_key:, role:, tool_name:, allowed_objects: nil, audit_context: {})
  require 'pg_query'
  @connection_class_name = connection_class_name
  @service_key = service_key
  @role = Assistant::DataPolicy.normalize_role(role)
  @allowed_objects = allowed_objects
  @tool_name = tool_name
  @audit_context = audit_context || {}
end

Instance Method Details

#execute(sql:, max_rows:) ⇒ Object 



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# File 'app/services/assistant/sql_broker.rb', line 28

def execute(sql:, max_rows:)
  started_at = Process.clock_gettime(Process::CLOCK_MONOTONIC)
  normalized_sql = normalize_sql(sql)
  first_word = normalized_sql.split(/\s+/).first&.upcase

  unless READ_ONLY_PREFIXES.include?(first_word)
    return blocked!("Only read-only queries allowed. Statement starts with: #{first_word}", normalized_sql, started_at)
  end

  objects = extract_objects(normalized_sql)
  disallowed = objects.reject { |obj| Assistant::DataPolicy.object_allowed?(role: @role, object_name: obj, allowed_objects: @allowed_objects) }
  if disallowed.any?
    return blocked!("Access denied. Restricted objects: #{disallowed.join(', ')}", normalized_sql, started_at, objects: objects)
  end

  rows = run_read_only(normalized_sql)
  redacted_columns = sensitive_columns(rows, objects, normalized_sql)
  rows = redact_rows(rows, redacted_columns) if redacted_columns.any?

  truncated = rows.size > max_rows
  col_hints = build_column_hint_map(rows, objects)
  response = {
    row_count: rows.size,
    rows: rows.first(max_rows),
    truncated: truncated,
    note: truncated ? "Showing #{max_rows} of #{rows.size} rows. Add LIMIT for better results." : nil,
    redacted_columns: redacted_columns.presence,
    column_hints: col_hints.presence
  }.compact

  audit!(
    sql: normalized_sql,
    status: 'success',
    duration_ms: elapsed_ms(started_at),
    referenced_objects: objects,
    returned_row_count: response[:rows].size,
    returned_column_count: response[:rows].first&.keys&.size.to_i
  )
  response
rescue PgQuery::ParseError => e
  errored!("Invalid SQL syntax: #{e.message}", normalized_sql, started_at)
rescue ActiveRecord::StatementInvalid => e
  errored!(e.message, normalized_sql, started_at, objects: objects_for_error(normalized_sql))
end