BetterstackLogger

An Elixir Logger backend for Betterstack.

Configuration

You will need a Betterstack source source_id which you can copy from your dashboard after you create a one.

config :logger,
  level: :info, # or other Logger level
  backends: [BetterstackLogger.HttpBackend]

config :betterstack_logger_backend,
  url: "https://in.logs.betterstack.com", # https://in.logs.bettersack.com is configured by default and you can set your own url
  level: :info, # Default BetterstackLogger level is :info. Note that log messages are filtered by the :logger application first
  source_id: "...", # the Betterstack source UUID, found  on your Betterstack dashboard
  flush_interval: 1_000, # minimum time in ms before a log batch is sent
  max_batch_size: 50, # maximum number of events before a log batch is sent
  metadata: :all # optionally you can drop keys if they exist with `metadata: [drop: [:list, :keys, :to, :drop]]`

Alternatively, you can configure these options in your system environment. Prefix the above option names with BETTERSTACK_.

export BETTERSTACK_URL="https://in.logs.betterstack.com"
export BETTERSTACK_API_KEY="..."
export BETTERSTACK_SOURCE_ID="..."

Usage

After configuring BetterstackLogger in config.exs, use Logger.info, Logger.error, ... functions to send log events to Betterstack app.

Usage with context

BetterstackLogger.context function signatures follows the one of Logger.metadata with slight modifications to parameters and return values.

# Merges map or keyword with existing context, will overwrite values.
BetterstackLogger.context(%{user: %{id: 3735928559}})
BetterstackLogger.context(user: %{id: 3735928559})

# Get all context entries or a value for a specific key
BetterstackLogger.context(:user)
BetterstackLogger.context()

# Deletes all context entries or specific context key/value
BetterstackLogger.context(user: nil)
BetterstackLogger.reset_context()

Current limitations

Betterstack log event BigQuery table schema is auto-generated per source. If you send a log with Logger.info("first", user: %{id: 1}), Betterstack will generate a metadata field of type integer. If in the future, you'll send a log event to the same source using Logger.info("first", user: %{id: "d9c2feff-d38a-4671-8de4-a1e7f7dd7e3c"1}), the log with a binary id will be rejected.

BetterstackLogger log payloads sent to Betterstack API are encoded using MsgPack

At this moment BetterstackLogger doesn't support full one-to-one logging of Elixir types and applies the following conversions:

• atoms converted to strings
• charlists are converted to strings
• tuples converted to arrays
• keyword lists converted to maps
• structs converted to maps
• NaiveDateTime and DateTime are converted using the String.Chars protocol
• pids are converted to strings

BetterstackLogger doesn't support:

• non-binary messages, e.g. Logger.info(%{user_count: 1337})

Exceptions

BetterstackLogger automatically logs all exceptions and formats stacktraces.

Troubleshooting

Run mix betterstack_logger.verify_config to test your config.

Installation

If available in Hex, the package can be installed by adding betterstack_logger_backend to your list of dependencies in mix.exs:

def deps do
  [
    {:betterstack_logger_backend, "~> 0.11.1"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/betterstack_logger_backend.