Function setupDNS

internal/xds/balancer/cdsbalancer/cdsbalancer_test.go:175–186

setupDNS unregisters the DNS resolver and registers a manual resolver for the same scheme. This allows the test to fake the DNS resolution by supplying the addresses of the test backends. Returns the following: - a channel onto which the DNS target being resolved is written to by the fake DNS resol

(t *testing.T)

//     fake DNS resolver
//   - a manual resolver which is used to fake the actual DNS resolution
func setupDNS(t *testing.T) (chan resolver.Target, *manual.Resolver) {
	targetCh := make(chan resolver.Target, 1)

	mr := manual.NewBuilderWithScheme("dns")
	mr.BuildCallback = func(target resolver.Target, _ resolver.ClientConn, _ resolver.BuildOptions) { targetCh <- target }

	dnsResolverBuilder := resolver.Get("dns")
	resolver.Register(mr)

	t.Cleanup(func() { resolver.Register(dnsResolverBuilder) })
	return targetCh, mr
}

// Performs the following setup required for tests:
//   - Spins up an xDS management server and the provided onStreamRequest