SecureLogFormatter

A secure formatter for Elixir Logger and replacement for Kernel.inspect/1. Using blacklisted keys and patterns SecureLogFormatter will identify and redact sensitive information from logs with ease.

Installation

def deps do
  [{:secure_log_formatter, "~> 1.0"}]
end

Like living on the edge? Want the latest and greatest?

def deps do
  [{:secure_log_formatter,
  	github: "localvore-today/secure_log_formatter"}]
end

Usage

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]"
    ]

Log formatting

Using SecureLogFormatter is easy, we only need to pass a tuple to the :format option for our logging backend(s):

config :logger,
  console: [format: {SecureLogFormatter, :format}]

If we give it awhirl:

iex> Logger.info("Customer Credit Card: 4111111111111111")
15:39:40.169 [info]  Customer Credit Card: [PRIVATE]

Replacing inspect/1

To leverage SecureLogFormatter.inspect/1 in place of Kernel.inspect/1 we can add two lines to the top of our files:

import Kernel, except: [inspect: 1]
import SecureLogFormatter, only: [inspect: 1]

With this change calls to inspect/1 will be handled by SecureLogFormatter:

iex> inspect(%{access_token: "secret_token", password: "abc123", username: "doomspork"})
"%{access_token: \"[PRIVATE]\", password: \"[PRIVATE]\", username: \"doomspork\"}"

License

SecureLogFormatter source code is released under MIT.

See LICENSE for more information.