main.rs

use log::{error, Level};
use opentelemetry::KeyValue;
use opentelemetry_appender_log::OpenTelemetryLogBridge;
use opentelemetry_sdk::logs::LoggerProvider;
use opentelemetry_sdk::Resource;
use opentelemetry_semantic_conventions::resource::SERVICE_NAME;

fn main() {
    // Setup LoggerProvider with a stdout exporter
    let exporter = opentelemetry_stdout::LogExporterBuilder::default()
        // uncomment the below lines to pretty print output.
        // .with_encoder(|writer, data|
        //    Ok(serde_json::to_writer_pretty(writer, &data).unwrap()))
        .build();
    let logger_provider = LoggerProvider::builder()
        .with_resource(Resource::new([KeyValue::new(
            SERVICE_NAME,
            "logs-basic-example",
        )]))
        .with_simple_exporter(exporter)
        .build();

    // Setup Log Appender for the log crate.
    let otel_log_appender = OpenTelemetryLogBridge::new(&logger_provider);
    log::set_boxed_logger(Box::new(otel_log_appender)).unwrap();
    log::set_max_level(Level::Error.to_level_filter());

    // Emit logs using macros from the log crate.
    // These logs gets piped through OpenTelemetry bridge and gets exported to stdout.
    error!(target: "my-target", "hello from {}. My price is {}", "apple", 2.99);
}