Loxe

Loxe is logfmt logger interface, it is built atop Elixir's standard Logger module.

Config

As of version 0.4.0, you can configure loxe to filter metadata:

config :loxe,
  # By default, if a value cannot be encoded by logfmt, it would normally raise a Protocol.UndefinedError
  # This field can be set to handle those cases differently:
  # * `:raise` the default
  # * `:placeholder` will replace the value with <protocol-unavailable>
  # * `:inspect` will use inspect instead of Logfmt.ValueEncoder if it is not available
  on_protocol_undefined: :raise,
  metadata: [
    only: [
      # keys that should always be included from the metadata
      :just_this,
      :and_this,
      :maybe_this,
    ],
    except: [
      # keys that should always be excluded from the metadata
      :not_this,
      :and_not_this,
    ],
  ]

Keep in mind this is a compile-time configuration therefore changing the above during runtime will have no effect.

Note The presence of loxe.metadata.only (even if just an empty list) changes the filtering behaviour completely. If present, every key from Logger.metadata/0 will be rejected by default except those specified in the list.

Note The presence of loxe.metadata.except has the default behaviour in which all keys are allowed by default (unless loxe.metadata.only is present in which case the default is to reject), except the keys listed.

Note This only affects fields from Logger.metadata/0, if you specified the list using Loxe's log functions, it will be present in the log line:

Loxe.Logger.metadata not_this: "something", and_not_this: "something-else"

Loxe.Logger.info "hi"
# => msg=hi
Loxe.Logger.info "hi", not_this: "should exist"
# => not_this="should exist" msg=hi

Usage

use Loxe.Logger

Loxe.Logger.info "message"
# => msg="message"

Loxe.Logger.info "message", [a: "Egg", b: "Rice"]
# => a="Egg" b="Rice" msg="message"

Installation

def deps do
  [
    {:loxe, git: "https://github.com/polyfox/loxe"}
  ]
end