http-database-greeter

Greeter Server

Greeter is an example app that demonstrates how to use github.com/instana/go-sensor to instrument an HTTP server that makes requests to a database with Instana. In this case we use PostgreSQL via github.com/lib/pq, but the same approach can be applied to any driver that is compatible with database/sql.

Usage

To start a server listening on localhost:8081 that connects to the database using postgres://postgres:mysecretpassword@localhost:5432/postgres?sslmode=disable connection string, run:

docker run --name http-database-greeter-postgres -e POSTGRES_PASSWORD=mysecretpassword -p 5432:5432 -d postgres
go run . -l localhost:8081 -db "postgres://postgres:mysecretpassword@localhost:5432/postgres?sslmode=disable"

In your browser navigate to localhost:8081/alice to see the greeting message for Alice.

Trace details

The request above will generate the following trace in your Instana dashboard:

The HTTP instrumentation has started a new entry span, potentially picking up the trace initiated by another service monitored by Instana or the End-User Monitoring script. This span is than used as a parent to trace the request processing, which is time.Sleep() in our case, and finally there is a database call that happens after the request handling is done.