feat: tlsmiddlebox experiment (#817)

See https://github.com/ooni/probe/issues/2124

internal/engine/experiment/tlsmiddlebox/dns.go

@@ -0,0 +1,29 @@
+package tlsmiddlebox
+
+//
+// DNS Lookup for tlsmiddlebox
+//
+
+import (
+	"context"
+	"time"
+
+	"github.com/ooni/probe-cli/v3/internal/measurexlite"
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+// DNSLookup performs a DNS Lookup for the passed domain
+func (m *Measurer) DNSLookup(ctx context.Context, index int64, zeroTime time.Time,
+	logger model.Logger, domain string, tk *TestKeys) ([]string, error) {
+	url := m.config.resolverURL()
+	trace := measurexlite.NewTrace(index, zeroTime)
+	ol := measurexlite.NewOperationLogger(logger, "DNSLookup #%d, %s, %s", index, url, domain)
+	// TODO(DecFox, bassosimone): We are currently using the DoH resolver, we will
+	// switch to the TRR2 resolver once we have it in measurexlite
+	// Issue: https://github.com/ooni/probe/issues/2185
+	resolver := trace.NewParallelDNSOverHTTPSResolver(logger, url)
+	addrs, err := resolver.LookupHost(ctx, domain)
+	ol.Stop(err)
+	tk.addQueries(trace.DNSLookupsFromRoundTrip())
+	return addrs, err
+}