betterstack_logger

OTP logger backend that sends log events to BetterStack Logs.

Quick start

Add to your rebar.config

{deps, [betterstack_logger]}.

add the logger handler settings to your sys.config

{betterstack_logger, [
    {logger,
        [
            {handler, betterstack_logs, betterstack_logger, #{
                level => info,
                config => #{
                    http_pool_options => [
                        {timeout, 15000},
                        {max_connections, 10}
                    ],

                    betterstack_source_token => <<"SOURCE_TOKEN_HERE">>,
                    extra_fields => [
                      {<<"_env">>, <<"prod">>}
                    ],
                    upload_batch_max_size => 50,
                    upload_batch_inteval_ms => 5000,
                    upload_failed_retry_count => 3,
                    upload_failed_retry_delay_ms => 1000
                },
                formatter => {
                    logger_formatter, #{
                        single_line => true,
                        template => [pid, " ", mfa,":",line, " => ", msg],
                        time_offset => "Z"
                    }
                },
                filters => [
                    %{remote_group_leader, {fun logger_filters:remote_gl/2, stop}},
                    %{progress, {fun logger_filters:progress/2, stop}},
                    %{sasl, {fun logger_filters:domain/2, {stop, sub, [otp, sasl]}}}
                ]
            }}
        ]}
]}

Or you can add it via logger API from your code:

logger:add_handler(my_handler, betterstack_logs, #{...}).

Note: It's not currently possible to set betterstack_logger as default handler via sys.config (or add the handler there directly under the kernel app), because sys.config is applied at kernel application start time and betterstack_logger application depends on kernel application (cyclic dependency).

Config properties

Property	Mandatory	Description
http_pool_options		hackney pool config.
betterstack_source_token	Y	BetterStack Source Token used for authentication.
extra_fields		Extra fields to be added to the message event.
upload_batch_max_size		Default: 50. The events are sent in batches. A batch is sent when is reaching the `upload_batch_max_size` size or a number of `upload_batch_inteval_ms` ms elapsed.
upload_batch_inteval_ms		Default: 5000. Number of milliseconds we can wait for events to accumulate. A batch is sent when is reaching the `upload_batch_max_size` size or a number of `upload_batch_inteval_ms` ms elapsed.
upload_failed_retry_count		Default: 3. In case a batch sending operation failed, how many times we retry to resubmit.
upload_failed_retry_delay_ms		Default: 1000. The delay between resubmitting failed batches.

Beside this custom settings, all other standard logger:handler_config() properties are accepted (level, filters, formatter).
Multiple instances of betterstack_logger handler can be started.