cmd/ocagent: fix Zipkin logical conflict detection typo

The Zipkin logical conflict detection had 2 errors:
a) By mistake, it resolved the receiver{Host, Port}
from the exporterHostPort address
b) During IP resolution to check say if "localhost" and "//zipkin"
were the same, if the results were the same, the ports weren't
checked for equivalence hence if we had:
    "localhost:9410" and "127.0.0.1:9411"
it would incorrectly report a logical conflict.

Added a regression test as well.

Fixes #233

cmd/ocagent/config.go

@@ -183,7 +183,7 @@ func (c *config) checkLogicalConflicts(blob []byte) error {
  zExporterHostPort, zReceiverHostPort)
  }
  zExpHost, zExpPort, _ := net.SplitHostPort(zExporterHostPort)
- zReceiverHost, zReceiverPort, _ := net.SplitHostPort(zExporterHostPort)
+ zReceiverHost, zReceiverPort, _ := net.SplitHostPort(zReceiverHostPort)
  if eqHosts(zExpHost, zReceiverHost) && zExpPort == zReceiverPort {
  return fmt.Errorf("ZipkinExporter address (%q) aka (%s on port %s)\nis the same as the receiver address (%q) aka (%s on port %s)",
  zExporterHostPort, zExpHost, zExpPort, zReceiverHostPort, zReceiverHost, zReceiverPort)
@@ -192,7 +192,7 @@ func (c *config) checkLogicalConflicts(blob []byte) error {
  // Otherwise, now let's resolve the IPs and ensure that they aren't the same
  zExpIPAddr, _ := net.ResolveIPAddr("ip", zExpHost)
  zReceiverIPAddr, _ := net.ResolveIPAddr("ip", zReceiverHost)
- if zExpIPAddr != nil && zReceiverIPAddr != nil && reflect.DeepEqual(zExpIPAddr, zReceiverIPAddr) {
+ if zExpIPAddr != nil && zReceiverIPAddr != nil && reflect.DeepEqual(zExpIPAddr, zReceiverIPAddr) && zExpPort == zReceiverPort {
  return fmt.Errorf("ZipkinExporter address (%q) aka (%+v)\nis the same as the\nreceiver address (%q) aka (%+v)",
  zExporterHostPort, zExpIPAddr, zReceiverHostPort, zReceiverIPAddr)
  }

cmd/ocagent/config_test.go

@@ -0,0 +1,62 @@
+// Copyright 2018, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+ "testing"
+
+ yaml "gopkg.in/yaml.v2"
+
+ "github.com/census-instrumentation/opencensus-service/exporter/exporterparser"
+)
+
+// Issue #233: Zipkin receiver and exporter loopback detection
+// would mistakenly report that "localhost:9410" and "localhost:9411"
+// were equal, due to a mistake in parsing out their addresses,
+// but also after IP resolution, the equivalence of ports was not being
+// checked.
+func TestZipkinReceiverExporterLogicalConflictChecks(t *testing.T) {
+ regressionYAML := []byte(`
+receivers:
+ zipkin:
+ address: "localhost:9410"
+
+exporters:
+ zipkin:
+ endpoint: "http://localhost:9411/api/v2/spans"
+`)
+
+ cfg, err := parseOCAgentConfig(regressionYAML)
+ if err != nil {
+ t.Fatalf("Unexpected YAML parse error: %v", err)
+ }
+ if err := cfg.checkLogicalConflicts(regressionYAML); err != nil {
+ t.Fatalf("Unexpected error: %v", err)
+ }
+
+ if g, w := cfg.Receivers.Zipkin.Address, "localhost:9410"; g != w {
+ t.Errorf("Receivers.Zipkin.EndpointURL mismatch\nGot: %s\nWant:%s", g, w)
+ }
+
+ var ecfg struct {
+ Exporters *struct {
+ Zipkin *exporterparser.ZipkinConfig `yaml:"zipkin"`
+ } `yaml:"exporters"`
+ }
+ _ = yaml.Unmarshal(regressionYAML, &ecfg)
+ if g, w := ecfg.Exporters.Zipkin.EndpointURL(), "http://localhost:9411/api/v2/spans"; g != w {
+ t.Errorf("Exporters.Zipkin.EndpointURL mismatch\nGot: %s\nWant:%s", g, w)
+ }
+}