go-test-trace

go-test-trace is like go test but it also generates distributed traces.

Generated traces are exported in OTLP to a OpenTelemetry collector. You need to run go-test-trace alongside a collector to export data to distributed tracing service.

Installation

go get -u github.com/rakyll/go-test-trace

Usage

You can use go-test-trace as a drop-in replacement for go test. The following example will generate a distributed trace and export it to a collector available at "127.0.0.1:55680".

$ go-test-trace ./example
=== RUN   TestStart
--- PASS: TestStart (0.50s)
=== RUN   TestStartWithOptions
--- PASS: TestStartWithOptions (1.00s)
=== RUN   TestFileParser
--- FAIL: TestFileParser (0.30s)
=== RUN   TestLoading
=== PAUSE TestLoading
=== RUN   TestLoading_abort
=== PAUSE TestLoading_abort
=== RUN   TestLoading_interrupt
=== PAUSE TestLoading_interrupt
=== CONT  TestLoading
=== CONT  TestLoading_abort
=== CONT  TestLoading_interrupt
--- PASS: TestLoading_interrupt (0.08s)
--- PASS: TestLoading (1.00s)
--- PASS: TestLoading_abort (2.50s)
FAIL
FAIL	github.com/rakyll/go-test-trace/example	4.823s
exit status 1
make: *** [default] Error 1

Alternatively, you can use -stdin option to parse the output of go test. This option won't be as accurate in terms of timestamps because it will generate trace spans as it sees output in stdin.

$ go test -v ./example | go-test-trace -stdin

You can export to any collector by using the endpoint flag:

$ go-test-trace -endpoint=my-otel-collector.io:9090 ./example

You can make the go-test-trace to participate into an existing trace with the traceparent flag.

$ go-test-trace -traceparent=00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01 ./example

Running the collector

An example collector configuration is available at example/collector.yaml. It exports to Honeycomb but you can choose to any other destination by changing the configuration. Please edit the write key and data set with your details from Honeycomb before using it.

Then, you can run the collector locally by the following command and export the traces to Honeycomb:

$ docker run --rm -p 4317:4317 -p 55680:55680 -p 8888:8888 \
    -v "${PWD}/example/collector.yaml":/collector.yaml \
    --name awscollector public.ecr.aws/aws-observability/aws-otel-collector:latest \
    --config collector.yaml;

You can use any configuration supported by ADOT or export to any other OpenTelemetry collector.