Using the logger as default handler is not supported.
To avoid cyclic dependency, it's not currently possible to set betterstack_logger as default handler via sys.config.
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Better Stack Erlang logging
Start logging in 3 steps
Collect logs from your Erlang application.
1. Install
Add betterstack_logger to your project dependencies using Rebar or Mix.
rebar.config
mix.exs
{deps, [betterstack_logger]}.def deps do
[
{:betterstack_logger, "~> 1.0"}
]
end2. Setup
Configure betterstack_logger in your application's configuration file,or add it programmatically via Logger API:
sys.config
call logger:add_handler in your start module
[
{betterstack_logger, [
{logger, [
{handler, betterstack_logs, betterstack_logger, #{
level => info,
config => #{
http_pool_options => [
{timeout, 15000},
{max_connections, 10}
],
betterstack_source_token => <<"$SOURCE_TOKEN">>,
extra_fields => [
{<<"_env">>, <<"prod">>}
],
upload_batch_max_size => 50,
upload_batch_inteval_ms => 5000,
upload_failed_retry_count => 3,
upload_failed_retry_delay_ms => 1000
},
formatter => {
logger_formatter, #{
single_line => true,
template => [pid, " ", mfa,":",line, " => ", msg],
time_offset => "Z"
}
},
filters => [
%{remote_group_leader, {fun logger_filters:remote_gl/2, stop}},
%{progress, {fun logger_filters:progress/2, stop}},
%{sasl, {fun logger_filters:domain/2, {stop, sub, [otp, sasl]}}}
]
}}
]}
]}
].logger:add_handler(my_handler, betterstack_logs, #{
level => info,
config => #{
http_pool_options => [
{timeout, 15000},
{max_connections, 10}
],
betterstack_source_token => <<"$SOURCE_TOKEN">>,
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]}}}
]
}).3. Start logging 🎉
Use the Erlang logger module as usual. Your log events will be sent to Better Stack automatically.
Example usage
logger:info("Application started successfully."),
logger:error("Failed to connect to database."),
logger:debug("Debugging value: ~p", [Value]).
You should see your logs in Better Stack → Live tail.
Huge thanks to Silviu Caragea who maintains the betterstack_logger library as an MIT-licenced open-source! ❤️
Need help?
Please reach out to us at hello@betterstack.com.
We're happy to help! 🙏
Additional information
Ensure your application terminates gracefully, giving the logger enough time to finish sending logs to BetterStack.
Use init:stop() to end your application properly.
Avoid using erlang:halt(), as it terminates all processes immediately and may drop your logs.