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Utilities

The nauthilus_util module provides several helper functions for Lua scripts in Nauthilus.

local nauthilus_util = require("nauthilus_util")

Functions

nauthilus_util.getenv​

Returns the value of an environment variable, cached via nauthilus_cache.

Syntax​

local val = nauthilus_util.getenv(name, default)

Parameters​

  • name (string) - The name of the environment variable.
  • default (string) - A default value if the environment variable is not set.

Returns​

  • val (string) - The value of the environment variable or the default value.

Example​

local api_url = nauthilus_util.getenv("API_URL", "http://localhost:8080")

nauthilus_util.exists_in_table​

Iterates over a flat Lua table (list) and checks if a string was found in the values.

Syntax​

local found = nauthilus_util.exists_in_table(tbl, element)

Parameters​

  • tbl (table) - The table to search in.
  • element (string) - The string to search for.

Returns​

  • found (boolean) - true if found, false otherwise.

Example​

local roles = {"admin", "user", "guest"}
if nauthilus_util.exists_in_table(roles, "admin") then
    -- User is an admin
end

nauthilus_util.get_current_timestamp​

Creates a timestamp string valid for logging purposes. It respects the TZ environment variable.

Syntax​

local ts = nauthilus_util.get_current_timestamp()

Returns​

  • ts (string) - A formatted timestamp string (e.g., "2006-01-02T15:04:05 -07:00").

Example​

local timestamp = nauthilus_util.get_current_timestamp()
-- result: "2024-01-21T15:00:00 +01:00"

nauthilus_util.table_length​

Calculates the length of a Lua table.

Syntax​

local len = nauthilus_util.table_length(tbl)

Parameters​

  • tbl (table) - The table to count.

Returns​

  • len (number) - The number of elements in the table.

Example​

local my_table = {a = 1, b = 2, c = 3}
local size = nauthilus_util.table_length(my_table)
-- size: 3

nauthilus_util.if_error_raise​

Checks if an error was set and calls the Lua error function to exit script execution. It ignores "redis: nil" or "OK" messages.

Syntax​

nauthilus_util.if_error_raise(err)

Parameters​

  • err (string) - The error message to check.

Example​

local result, err = nauthilus_redis.redis_get("handle", "my_key")
nauthilus_util.if_error_raise(err)

nauthilus_util.is_table​

Returns true if the given parameter is of type table.

Syntax​

local result = nauthilus_util.is_table(object)

Parameters​

  • object (any) - The object to check.

Example​

local data = {key = "value"}
if nauthilus_util.is_table(data) then
    -- It is a table
end

nauthilus_util.is_string​

Returns true if the given parameter is of type string.

Syntax​

local result = nauthilus_util.is_string(object)

Parameters​

  • object (any) - The object to check.

Example​

if nauthilus_util.is_string("hello") then
    -- It is a string
end

nauthilus_util.is_number​

Returns true if the given parameter is of type number.

Syntax​

local result = nauthilus_util.is_number(object)

Parameters​

  • object (any) - The object to check.

Example​

if nauthilus_util.is_number(123) then
    -- It is a number
end

nauthilus_util.get_redis_key​

Returns a Redis key with the prefix from the request, if available.

Syntax​

local key = nauthilus_util.get_redis_key(request, key)

Parameters​

  • request (table) - The Nauthilus request object.
  • key (string) - The base Redis key.

Returns​

  • key (string) - The prefixed Redis key.

Example​

local key = nauthilus_util.get_redis_key(request, "my_data")
-- result: "nt_:my_data" (if prefix is "nt_")

nauthilus_util.toboolean​

Converts a string value into a boolean.

Syntax​

local bool = nauthilus_util.toboolean(str)

Parameters​

  • str (string) - The string to convert.

Returns​

  • bool (boolean) - false if the lower-cased string is "false", "0", or empty. true otherwise.

Example​

local is_enabled = nauthilus_util.toboolean("true") -- true
local is_disabled = nauthilus_util.toboolean("0") -- false

nauthilus_util.generate_random_string​

Creates a random string of a specified length.

Syntax​

local str = nauthilus_util.generate_random_string(length)

Parameters​

  • length (number) - The desired length of the string.

Returns​

  • str (string) - The random alphanumeric string.

Example​

local nonce = nauthilus_util.generate_random_string(16)

nauthilus_util.is_routable_ip​

Checks if an IP address is routable on the internet.

Syntax​

local routable = nauthilus_util.is_routable_ip(ip)

Parameters​

  • ip (string) - The IP address to check.

Returns​

  • routable (boolean) - true if routable, false for private or reserved ranges.

Example​

local ok = nauthilus_util.is_routable_ip("8.8.8.8") -- true
local internal = nauthilus_util.is_routable_ip("192.168.1.1") -- false

Logging Functions​

The following functions log messages at different levels. They respect the configured log level and format.

Syntax​

nauthilus_util.log_debug(logging, result)
nauthilus_util.log_info(logging, result)
nauthilus_util.log_notice(logging, result)
nauthilus_util.log_warn(logging, result)
nauthilus_util.log_error(logging, result, err_string)

Parameters​

  • logging (table) - The logging configuration object.
  • result (table) - A table of key/value pairs to log.
  • err_string (string) - (Only for log_error) An additional error message.

Example​

local log_data = {
    user = request.username,
    action = "login",
    status = "success"
}
nauthilus_util.log_info(request.logging, log_data)