Óg is a small collection of debugging helper functions. Og is a debugging tool primarily intendend for development, the use of ordinary Logger is preferred for production.

Summary

• log/2 - logs the data transformed by the inspector function and returns :ok

• log_r/2 - logs the data transformed by the inspector function and returns the original data.

• Inspection of the data before logging it can be helpful in a debugging context for example for

  • Avoiding the Protocol.UndefinedError when logging tuples.
  • Not needing to require Logger

• Formatting with Kernel.inspect on the data carries an overhead so Og.log/2 and Og.log_r/2 should be probably be reserved for debugging code in :dev environments.

Configuration

config :logger, :og,
  kernel_opts: [width: 70],
  apex_opts: [numbers: :false, color: :false],
  sanitize_by_default: :false,
  default_inspector: :kernel

Configuration options

• kernel_opts - corresponds to elixir inspect opts for IO.inspect/2 and Kernel.inspect/2, refer to https://hexdocs.pm/elixir/Inspect.Opts.html

• apex_opts - corresponds to options for the Apex.Format.format/2 function, refer to https://github.com/BjRo/apex/blob/master/lib/apex/format.ex

• sanitize_by_default - defaults to :false, when set to :true, an attempt will be made to apply the SecureLogFormatter.sanitize/1 function on the data before applying the inspection function. For this function to take any effect, the settings for SecureLogFormatter must also be placed in config.exs. See secure_log_formatter for more details.

• default_inspector - corresponds to the default inspector which will apply to the data passed to the log function. This can be overriden in the options of the log function. The options are :kernel or :apex, the default is :kernel.

Example configuration for secure_log_formatter, as referenced at the following secure_log_formatter url.

config :logger,
secure_log_formatter:
  [
    # Map and Keyword List keys who's value should be hidden
    fields: ["password", "credit_card", ~r/.*_token/],

    # Patterns which if found, should be hidden
    patterns: [~r/4[0-9]{15}/] # Simple credit card example

    # defaults to "[REDACTED]"
    replacement: "[PRIVATE]"
  ]