From 861f754dadbfc2dfa84939879caa4065da89ae1b Mon Sep 17 00:00:00 2001 From: Matt Keeler Date: Wed, 19 Feb 2020 14:41:43 -0500 Subject: [PATCH] Properly detect no alt domain set (#7323) --- agent/dns.go | 8 +++++++- agent/dns_test.go | 15 +++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/agent/dns.go b/agent/dns.go index e44a6fda96..c44ee69b0a 100644 --- a/agent/dns.go +++ b/agent/dns.go @@ -190,7 +190,13 @@ func (d *DNSServer) ListenAndServe(network, addr string, notif func()) error { d.mux = dns.NewServeMux() d.mux.HandleFunc("arpa.", d.handlePtr) d.mux.HandleFunc(d.domain, d.handleQuery) - if d.altDomain != "" { + // this is not an empty string check because NewDNSServer will have + // converted the configured alt domain into an FQDN which will ensure that + // the value ends with a ".". Therefore "." is the empty string equivalent + // for originally having no alternate domain set. If there is a reason + // why consul should be configured to handle the root zone I have yet + // to think of it. + if d.altDomain != "." { d.mux.HandleFunc(d.altDomain, d.handleQuery) } d.toggleRecursorHandlerFromConfig(cfg) diff --git a/agent/dns_test.go b/agent/dns_test.go index 57d420af2d..a56aee2a04 100644 --- a/agent/dns_test.go +++ b/agent/dns_test.go @@ -188,6 +188,21 @@ func TestDNS_Over_TCP(t *testing.T) { } } +func TestDNS_EmptyAltDomain(t *testing.T) { + t.Parallel() + a := NewTestAgent(t, t.Name(), "") + defer a.Shutdown() + testrpc.WaitForLeader(t, a.RPC, "dc1") + + m := new(dns.Msg) + m.SetQuestion("consul.service.", dns.TypeA) + + c := new(dns.Client) + in, _, err := c.Exchange(m, a.DNSAddr()) + require.NoError(t, err) + require.Empty(t, in.Answer) +} + func TestDNS_NodeLookup(t *testing.T) { t.Parallel() a := NewTestAgent(t, t.Name(), "")