Selecto.LogSanitizer (Selecto v0.4.5)

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Sanitizes SQL queries and parameters for safe logging.

This module ensures that sensitive data from query parameters is never written to logs, while still providing useful debugging information.

Security

  • Parameters are replaced with placeholders like $1, $2, etc.
  • Parameter values are NEVER logged
  • SQL structure is preserved for debugging purposes
  • Query previews are truncated to prevent log bloat

Usage

iex> LogSanitizer.sanitize_query("SELECT * FROM users WHERE id = $1", [123])
"SELECT * FROM users WHERE id = $1 [1 param(s) redacted]"

iex> LogSanitizer.sanitize_params([1, "secret", %{key: "value"}])
"[3 param(s) redacted]"

Summary

Functions

safe_context(context)

Creates a safe log context map with sanitized values.

sanitize_error(error)

Sanitizes an error for logging, removing any embedded parameter values.

sanitize_params(params)

Returns a safe representation of parameters for logging.

sanitize_query(query, params \\ [], opts \\ [])

Sanitizes a query string for logging, optionally with parameter count.

Functions

safe_context(context)

@spec safe_context(keyword()) :: map()

Creates a safe log context map with sanitized values.

Examples

iex> safe_context(query: "SELECT...", params: [1,2,3], error: %RuntimeError{})
%{query: "SELECT... [3 param(s) redacted]", error: "RuntimeError: ..."}

sanitize_error(error)

@spec sanitize_error(term()) :: String.t()

Sanitizes an error for logging, removing any embedded parameter values.

Examples

iex> sanitize_error(%RuntimeError{message: "error"})
"Elixir.RuntimeError: error"

sanitize_params(params)

@spec sanitize_params(list()) :: String.t()

Returns a safe representation of parameters for logging.

NEVER logs actual parameter values - only the count and types.

Examples

iex> sanitize_params([1, "secret", nil])
"[3 param(s): integer, binary, nil]"

iex> sanitize_params([])
"[0 params]"

sanitize_query(query, params \\ [], opts \\ [])

@spec sanitize_query(String.t() | nil, list(), keyword()) :: String.t()

Sanitizes a query string for logging, optionally with parameter count.

Returns the query with a note about redacted parameters.

Options

  • :max_length - Maximum length of query to include (default: 500)
  • :show_param_count - Whether to show parameter count (default: true)

Examples

iex> sanitize_query("SELECT * FROM users WHERE id = $1", [123])
"SELECT * FROM users WHERE id = $1 [1 param(s) redacted]"

iex> sanitize_query("SELECT * FROM users", [])
"SELECT * FROM users"