jaskier

Jaskier

A fun side project, writing a column-oriented datastore to store and query tracing data using the OTLP format.

Running the service

You can either run the service locally directly with go run, or use the buildable Docker image.
From within the project's main directory:

go run main.go --config config.yml

docker build -t jaskier .
docker run -p 2021:2021 --name jaskier -d \
	--mount type=bind,source="$(pwd)"/config.yml,target=/root/config.yml \
	jaskier sh -c "/root/jaskier --config /root/config.yml"

The server will listen on port 2021 by default.

Configuration

The binary accepts a configuration file for configuring the behavior of the application.
The format of the configuration is available in cli/config.go.

Here is a sample config file:

otlp:
  endpoint: api.honeycomb.io:443
  headers:
    x-honeycomb-team: <MY SECRET KEY>
    x-honeycomb-dataset: jaskier
sample_ratio: 0.5

Sending traces

You can send traces by setting up an OTLP exporter within your OpenTelemetry application. For example, in Go:

import (
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
	sdktrace "go.opentelemetry.io/otel/sdk/trace"
)

exp, _ = otlptracegrpc.New(context.Background(),
	otlptracegrpc.WithEndpoint("localhost:2021"),
	otlptracegrpc.WithInsecure(),
	otlptracegrpc.WithHeaders(map[string]string{
		"dataset": "my_dataset",
	}),
)
tp := sdktrace.NewTracerProvider(sdktrace.WithBatcher(exp))
otel.SetTracerProvider(tp)

You can then use tracing as you would normally do with any OpenTelemetry project:

_, span := otel.Tracer("").Start(context.Background(), "test_span")
defer span.End()

Querying

TODO