Hands-On Software Engineering with Golang

Putting it all together

The main file prepares a microservice deployment environment via a call to the deployServices helper function. The idea here is to string together the services in such a manner so that tracing a request through the system will yield an interesting trace graph. Let's see how this is done.

First, the helper starts three Provider instances and keeps track of their addresses:

var err error
providerAddrs := make([]string, 3)
for i := 0; i < len(providerAddrs); i++ {
    provider := service.NewProvider(fmt.Sprintf("vendor-%d", i))
    if providerAddrs[i], err = provider.Serve(ctx); err != nil {
        return nil, err
    }
}

Then, it starts an Aggregator instance and sets it up to connect to providers 1 and 2 from the preceding list:

aggr1 ...