opentelemetry-go/example

Example

Here is a collection of OpenTelemtry-Go examples showcasing basic functionality.

OTLP

This example demonstrates how to export trace and metric data from an application using OpenTelemetry's own wire protocal OTLP. We will also walk you through configuring a collector to accept OTLP exports.

How to run?

Prequisites

• go >=1.14 installed
• OpenTelemetry collector is available

Start the Application

An example application is included in example/otlp. It simulates the process of scribing a spell scroll (e.g. in D&D). The application has been instrumented and exports both trace and metric data via OTLP to any listening receiver. To run it:

go get -d go.opentelemetry.io/otel
cd $GOPATH/go.opentelemetry.io/otel/example/otlp
go run main.go

The application is currently configured to transmit exported data to localhost:55680. See main.go for full details.

Note, if the receiver is incorrectly configured to take in metric data, the application may complain about being unable to connect.

Configure the Collector

Follow the instructions on the website to install a working instance of the collector. This example assumes you have the collector installed locally.

To configure the collector to accept OTLP traffic from our application, ensure that it has the following configs:

receivers:
    otlp:
        endpoint: 0.0.0.0:55680   # listens to localhost:55680

    # potentially other receivers

service:
    pipelines:

        traces:
            receivers:
                - otlp
                # potentially other receivers
            processors: # whatever processors you need
            exporters: # wherever you want your data to go

        metrics:
            receivers:
                -otlp
                # potentially other receivers
            processors: etc
            exporters: etc

    # other services

An example config has been provided at example-otlp-config.yaml.

Then to run:

./[YOUR_COLLECTOR_BINARY]  --config [PATH_TO_CONFIG]

If you use the example config, it's set to export to stdout. If you run the collector on the same machine as the example application, you should see trace and metric outputs from the collector.

HTTP

This is a simple example that demonstrates tracing http request from client to server. The example shows key aspects of tracing such as:

• Root Span (on Client)
• Child Span (on Client)
• Child Span from a Remote Parent (on Server)
• SpanContext Propagation (from Client to Server)
• Span Events
• Span Attributes

Example uses

• open-telemetry SDK as trace instrumentation provider,
• httptrace plugin to facilitate tracing http request on client and server
• http trace_context propagation to propagate SpanContext on the wire.
• stdout exporter to print information about spans in the terminal

How to run?

Prequisites

• go 1.13 installed
• GOPATH is configured.

1 Download git repo

GO111MODULE="" go get -d go.opentelemetry.io/otel

2 Start Server

cd $GOPATH/src/go.opentelemetry.io/otel/example/http/
go run ./server/server.go

3 Start Client

cd $GOPATH/src/go.opentelemetry.io/otel/example/http/
go run ./client/client.go

4 Check traces in stdout

The spans should be visible in stdout in the order that they were exported.