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Instrumented HTTP and Database Example

main.go shows how simple it is to get started. It contains an example instrumented web server in which we query a database. This example shows how trace context is propagated using the request's context.Context. Additionally, it shows how to bootstrap the instrumentation for the database layer, especially the SQL Commenter which allows SWO to associate database queries with traces.

To run, set the SW_APM_SERVICE_KEY environment variable, then run go run . in this directory. For example:

SW_APM_SERVICE_KEY="${SW_APM_TOKEN}:golang-testbed" go run .

If the agent successfully connects, you will see a log line like this:

[solarwinds_apm] Got dynamic settings. The SolarWinds Observability APM agent (0x140001007e0) is ready.

Call the http service like so:

% curl -ik -d "hello world" http://localhost:8080/echo
HTTP/1.1 200 OK
Access-Control-Expose-Headers: X-Trace
X-Trace: 00-61b3d30b3695fc559ed760d75460c4ed-09c1e095da6f1c51-01
Date: Thu, 03 Aug 2023 15:39:44 GMT
Content-Length: 11
Content-Type: text/plain; charset=utf-8

hello world%

The X-Trace response header is in the W3C Trace Context Traceparent Header format. The 01 at the end indicates the request was sampled, meaning the trace will show up in your SolarWinds APM dashboard. 00 at the end will indicate not sampled.