Client library for embedded metric format logs

[mbergkvist]

Are there any plans on a Rust library for embedded metric format logs, adding to the list here?

[calavera]

Not at the moment. We'd definitely accept contributions if anyone wants to build one.

[BMorinDrifter]

I'm working on one that uses the metrics crate as a front end. Will share when I get to a minimum viable product.

[BMorinDrifter]

Alright, I have a thing that works, figuring out how to get this on github, etc.
Long time programmer, new to Open Source...

Example

use lambda_runtime::{run, service_fn, Error, LambdaEvent};
use serde::{Deserialize, Serialize};

#[derive(Deserialize)]
struct Request {}

#[derive(Serialize)]
struct Response {
    req_id: String,
}

async fn function_handler(
    metrics: &metrics_cloudwatch_embedded::Collector,
    event: LambdaEvent<Request>,
) -> Result<Response, Error> {
    let resp = Response {
        req_id: event.context.request_id.clone(),
    };

    metrics::increment_counter!("requests", "Method" => "Default");

    metrics
        .set_property("RequestId", event.context.request_id)
        .flush()?;
    Ok(resp)
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_env_filter(tracing_subscriber::filter::EnvFilter::from_default_env())
        .with_target(false)
        .without_time()
        .compact()
        .init();

    let metrics = metrics_cloudwatch_embedded::Builder::new()
        .cloudwatch_namespace("MetricsTest")
        .with_dimension(
            "Function",
            std::env::var("AWS_LAMBDA_FUNCTION_NAME").unwrap(),
        )
        .init()
        .unwrap();

    run(service_fn(|event| function_handler(metrics, event))).await
}

Output

START RequestId: 6d01b155-a8e7-4903-934f-8f4c9b524552 Version: $LATEST
{"_aws":{"Timestamp":1687687814982,"CloudWatchMetrics":[{"Namespace":"MetricsTest","Dimensions":[["Function","Method"]],"Metrics":[{"Name":"requests"}]}]},"Function":"MetricsTest","Method":"Default","RequestId":"6d01b155-a8e7-4903-934f-8f4c9b524552","requests":1}
END RequestId: 6d01b155-a8e7-4903-934f-8f4c9b524552
REPORT RequestId: 6d01b155-a8e7-4903-934f-8f4c9b524552 Duration: 1.14 ms Billed Duration: 8 ms Memory Size: 128 MB Max Memory Used: 12 MB Init Duration: 6.62 ms

[BMorinDrifter]

Alright that was less painful than I thought...

https://github.com/BMorinDrifter/metrics-cloudwatch-embedded

[calavera]

That's really cool! Thanks for making it open source

[BMorinDrifter]

It's on crates.io now
https://crates.io/crates/metrics_cloudwatch_embedded

[BMorinDrifter]

Added some lambda specific integration to provide some of the metrics features found in Lambda Power Tools for other runtimes.

Under the hood tower::Service is used to hook up decoration before the handler (or inner service) and to flush metrics after the handler.

Example

use lambda_runtime::{Error, LambdaEvent};
use metrics_cloudwatch_embedded::lambda::handler::run;
use serde::{Deserialize, Serialize};

#[derive(Deserialize)]
struct Request {}

#[derive(Serialize)]
struct Response {
}

async fn function_handler(event: LambdaEvent<Request>) -> Result<Response, Error> {
    metrics::increment_counter!("requests", "Method" => "Default");

    Ok(Response {})
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_env_filter(tracing_subscriber::filter::EnvFilter::from_default_env())
        .with_target(false)
        .without_time()
        .compact()
        .init();

    let metrics = metrics_cloudwatch_embedded::Builder::new()
        .cloudwatch_namespace("MetricsExample")
        .with_dimension("Function", std::env::var("AWS_LAMBDA_FUNCTION_NAME").unwrap())
        .lambda_cold_start_metric("ColdStart")
        .with_lambda_request_id("RequestId")
        .init()
        .unwrap();

    run(metrics, function_handler).await
}

Output

START RequestId: 4bd2d365-3792-46c8-9b6c-6132f9630fbb Version: $LATEST
{"_aws":{"Timestamp":1687947426188,"CloudWatchMetrics":[{"Namespace":"MetricsTest","Dimensions":[["Function"]],"Metrics":[{"Name":"ColdStart","Unit":"Count"}]}]},"Function":"MetricsTest","RequestId":"4bd2d365-3792-46c8-9b6c-6132f9630fbb","ColdStart":1}
{"_aws":{"Timestamp":1687947426188,"CloudWatchMetrics":[{"Namespace":"MetricsTest","Dimensions":[["Function","Method"]],"Metrics":[{"Name":"requests"}]}]},"Function":"MetricsTest","Method":"Default","RequestId":"4bd2d365-3792-46c8-9b6c-6132f9630fbb","requests":1}
END RequestId: 4bd2d365-3792-46c8-9b6c-6132f9630fbb
REPORT RequestId: 4bd2d365-3792-46c8-9b6c-6132f9630fbb Duration: 1.28 ms Billed Duration: 22 ms Memory Size: 128 MB Max Memory Used: 14 MB Init Duration: 20.02 ms

[calavera]

ohhhh, that's super nice!