diff --git a/middleware/proxy/upstream.go b/middleware/proxy/upstream.go index 59e1a534f..cabcd9ba8 100644 --- a/middleware/proxy/upstream.go +++ b/middleware/proxy/upstream.go @@ -4,8 +4,10 @@ import ( "fmt" "io" "io/ioutil" + "log" "net" "net/http" + "net/url" "strconv" "strings" "sync/atomic" @@ -14,7 +16,6 @@ import ( "github.com/coredns/coredns/middleware" "github.com/coredns/coredns/middleware/pkg/dnsutil" "github.com/coredns/coredns/middleware/pkg/tls" - "github.com/mholt/caddy/caddyfile" "github.com/miekg/dns" ) @@ -229,16 +230,38 @@ func parseBlock(c *caddyfile.Dispenser, u *staticUpstream) error { func (u *staticUpstream) healthCheck() { for _, host := range u.Hosts { - port := "" - if u.HealthCheck.Port != "" { - port = ":" + u.HealthCheck.Port + var hostName, checkPort string + + // The DNS server might be an HTTP server. If so, extract its name. + if url, err := url.Parse(host.Name); err == nil { + hostName = url.Host + } else { + hostName = host.Name } - hostURL := host.Name + port + u.HealthCheck.Path + + // Extract the port number from the parsed server name. + checkHostName, checkPort, err := net.SplitHostPort(hostName) + if err != nil { + checkHostName = hostName + } + + if u.HealthCheck.Port != "" { + checkPort = u.HealthCheck.Port + } + + hostURL := "http://" + net.JoinHostPort(checkHostName, checkPort) + u.HealthCheck.Path + host.Unhealthy = false + if r, err := http.Get(hostURL); err == nil { io.Copy(ioutil.Discard, r.Body) r.Body.Close() - host.Unhealthy = r.StatusCode < 200 || r.StatusCode >= 400 + if r.StatusCode < 200 || r.StatusCode >= 400 { + log.Printf("[WARNING] Health check URL %s returned HTTP code %d\n", + hostURL, r.StatusCode) + host.Unhealthy = true + } } else { + log.Printf("[WARNING] Health check probe failed: %v\n", err) host.Unhealthy = true } } diff --git a/test/proxy_http_health_test.go b/test/proxy_http_health_test.go new file mode 100644 index 000000000..9bfc3b209 --- /dev/null +++ b/test/proxy_http_health_test.go @@ -0,0 +1,95 @@ +package test + +import ( + "io" + "io/ioutil" + "log" + "net/http" + "net/http/httptest" + "net/url" + "testing" + + "github.com/coredns/coredns/middleware/proxy" + "github.com/coredns/coredns/middleware/test" + "github.com/coredns/coredns/request" + "github.com/miekg/dns" +) + +func TestProxyWithHTTPCheckOK(t *testing.T) { + log.SetOutput(ioutil.Discard) + + healthCheckServer := httptest.NewServer(http.HandlerFunc( + func(w http.ResponseWriter, r *http.Request) { + w.WriteHeader(http.StatusOK) + io.WriteString(w, "OK\n") + })) + defer healthCheckServer.Close() + + healthCheckURL, err := url.Parse(healthCheckServer.URL) + if err != nil { + t.Fatal(err) + } + healthCheckPort := healthCheckURL.Port() + + name, rm, err := test.TempFile(".", exampleOrg) + if err != nil { + t.Fatalf("failed to create zone: %s", err) + } + defer rm() + + // We have to bind to 127.0.0.1 because the server started by + // httptest.NewServer does, and the IP addresses of the backend + // DNS and HTTP servers must match. + authoritativeCorefile := `example.org:0 { + bind 127.0.0.1 + file ` + name + ` +} +` + + authoritativeInstance, err := CoreDNSServer(authoritativeCorefile) + if err != nil { + t.Fatalf("Could not get CoreDNS authoritative instance: %s", err) + } + + authoritativeAddr, _ := CoreDNSServerPorts(authoritativeInstance, 0) + if authoritativeAddr == "" { + t.Fatalf("Could not get CoreDNS authoritative instance UDP listening port") + } + defer authoritativeInstance.Stop() + + proxyCorefile := `example.org:0 { + proxy . ` + authoritativeAddr + ` { + health_check /health:` + healthCheckPort + ` 1s + + } +} +` + + proxyInstance, err := CoreDNSServer(proxyCorefile) + if err != nil { + t.Fatalf("Could not get CoreDNS proxy instance: %s", err) + } + + proxyAddr, _ := CoreDNSServerPorts(proxyInstance, 0) + if proxyAddr == "" { + t.Fatalf("Could not get CoreDNS proxy instance UDP listening port") + } + defer proxyInstance.Stop() + + p := proxy.NewLookup([]string{proxyAddr}) + state := request.Request{W: &test.ResponseWriter{}, Req: new(dns.Msg)} + resp, err := p.Lookup(state, "example.org.", dns.TypeA) + if err != nil { + t.Fatal("Expected to receive reply, but didn't") + } + // expect answer section with A record in it + if len(resp.Answer) == 0 { + t.Fatalf("Expected to at least one RR in the answer section, got none: %s", resp) + } + if resp.Answer[0].Header().Rrtype != dns.TypeA { + t.Errorf("Expected RR to A, got: %d", resp.Answer[0].Header().Rrtype) + } + if resp.Answer[0].(*dns.A).A.String() != "127.0.0.1" { + t.Errorf("Expected 127.0.0.1, got: %s", resp.Answer[0].(*dns.A).A.String()) + } +}