[service] fix: use ipv6-aware host and port concatenation function (#…

…10343)

#### Description
Fixing the bug: the latest version of otel-collector failed to start
with ipv6 metrics endpoint service telemetry.

This problem began to occur after
#9037 with
the feature gate flag enabled was merged. This problem is probably an
implementation omission because the enabled codepath, which was
originally added by
#7871, is
marked as WIP.

You can reproduce the issue with the config and the environment variable
(`MY_POD_IP=::1`).
```yaml
service:
  telemetry:
    logs:
      encoding: json
    metrics:
      address: '[${env:MY_POD_IP}]:8888'
```

#### Link to tracking issue
Fixes
#10011

---------

Co-authored-by: Tyler Helmuth <[email protected]>

.chloggen/fix_ipv6_too_many_colon.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: service
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fixed a bug that caused otel-collector to fail to start with ipv6 metrics endpoint service telemetry.
+
+# One or more tracking issues or pull requests related to the change
+issues: [10011]
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

internal/testutil/testutil.go

@@ -4,6 +4,7 @@
 package testutil // import "go.opentelemetry.io/collector/internal/testutil"
 
 import (
+ "fmt"
  "net"
  "os/exec"
  "runtime"
@@ -31,15 +32,44 @@ func GetAvailableLocalAddress(t testing.TB) string {
  // which do not show up under the "netstat -ano" but can only be found by
  // "netsh interface ipv4 show excludedportrange protocol=tcp". We'll use []exclusions to hold those ranges and
  // retry if the port returned by GetAvailableLocalAddress falls in one of those them.
+ network := "tcp4"
  var exclusions []portpair
  portFound := false
  if runtime.GOOS == "windows" {
- exclusions = getExclusionsList(t)
+ exclusions = getExclusionsList(network, t)
  }
 
  var endpoint string
  for !portFound {
- endpoint = findAvailableAddress(t)
+ endpoint = findAvailableAddress(network, t)
+ _, port, err := net.SplitHostPort(endpoint)
+ require.NoError(t, err)
+ portFound = true
+ if runtime.GOOS == "windows" {
+ for _, pair := range exclusions {
+ if port >= pair.first && port <= pair.last {
+ portFound = false
+ break
+ }
+ }
+ }
+ }
+
+ return endpoint
+}
+
+// GetAvailableLocalIPv6Address is IPv6 version of GetAvailableLocalAddress.
+func GetAvailableLocalIPv6Address(t testing.TB) string {
+ network := "tcp6"
+ var exclusions []portpair
+ portFound := false
+ if runtime.GOOS == "windows" {
+ exclusions = getExclusionsList(network, t)
+ }
+
+ var endpoint string
+ for !portFound {
+ endpoint = findAvailableAddress(network, t)
  _, port, err := net.SplitHostPort(endpoint)
  require.NoError(t, err)
  portFound = true
@@ -72,8 +102,17 @@ func GetAvailableLocalAddressPrometheus(t testing.TB) *config.Prometheus {
  }
 }
 
-func findAvailableAddress(t testing.TB) string {
- ln, err := net.Listen("tcp", "localhost:0")
+func findAvailableAddress(network string, t testing.TB) string {
+ var host string
+ switch network {
+ case "tcp", "tcp4":
+ host = "localhost"
+ case "tcp6":
+ host = "[::1]"
+ }
+ require.NotZero(t, host, "network must be either of tcp, tcp4 or tcp6")
+
+ ln, err := net.Listen("tcp", fmt.Sprintf("%s:0", host))
  require.NoError(t, err, "Failed to get a free local port")
  // There is a possible race if something else takes this same port before
  // the test uses it, however, that is unlikely in practice.
@@ -84,8 +123,16 @@ func findAvailableAddress(t testing.TB) string {
 }
 
 // Get excluded ports on Windows from the command: netsh interface ipv4 show excludedportrange protocol=tcp
-func getExclusionsList(t testing.TB) []portpair {
- cmdTCP := exec.Command("netsh", "interface", "ipv4", "show", "excludedportrange", "protocol=tcp")
+func getExclusionsList(network string, t testing.TB) []portpair {
+ var cmdTCP *exec.Cmd
+ switch network {
+ case "tcp", "tcp4":
+ cmdTCP = exec.Command("netsh", "interface", "ipv4", "show", "excludedportrange", "protocol=tcp")
+ case "tcp6":
+ cmdTCP = exec.Command("netsh", "interface", "ipv6", "show", "excludedportrange", "protocol=tcp")
+ }
+ require.NotZero(t, cmdTCP, "network must be either of tcp, tcp4 or tcp6")
+
  outputTCP, errTCP := cmdTCP.CombinedOutput()
  require.NoError(t, errTCP)
  exclusions := createExclusionsList(string(outputTCP), t)

internal/testutil/testutil_test.go

@@ -29,14 +29,32 @@ func TestGetAvailableLocalAddress(t *testing.T) {
  require.Nil(t, ln1)
 }
 
+func TestGetAvailableLocalIpv6Address(t *testing.T) {
+ endpoint := GetAvailableLocalIPv6Address(t)
+
+ // Endpoint should be free.
+ ln0, err := net.Listen("tcp", endpoint)
+ require.NoError(t, err)
+ require.NotNil(t, ln0)
+ t.Cleanup(func() {
+ assert.NoError(t, ln0.Close())
+ })
+
+ // Ensure that the endpoint wasn't something like ":0" by checking that a
+ // second listener will fail.
+ ln1, err := net.Listen("tcp", endpoint)
+ require.Error(t, err)
+ require.Nil(t, ln1)
+}
+
 func TestCreateExclusionsList(t *testing.T) {
  // Test two examples of typical output from "netsh interface ipv4 show excludedportrange protocol=tcp"
  emptyExclusionsText := `
 
 Protocol tcp Port Exclusion Ranges
 
-Start Port End Port 
----------- -------- 
+Start Port End Port
+---------- --------
 
 * - Administered port exclusions.`
 

service/internal/proctelemetry/config.go

@@ -8,6 +8,7 @@ import (
  "encoding/json"
  "errors"
  "fmt"
+ "net"
  "net/http"
  "net/url"
  "os"
@@ -175,7 +176,7 @@ func initPrometheusExporter(prometheusConfig *config.Prometheus, asyncErrorChann
  return nil, nil, fmt.Errorf("error creating otel prometheus exporter: %w", err)
  }
 
- return exporter, InitPrometheusServer(promRegistry, fmt.Sprintf("%s:%d", *prometheusConfig.Host, *prometheusConfig.Port), asyncErrorChannel), nil
+ return exporter, InitPrometheusServer(promRegistry, net.JoinHostPort(*prometheusConfig.Host, fmt.Sprintf("%d", *prometheusConfig.Port)), asyncErrorChannel), nil
 }
 
 func initPullExporter(exporter config.MetricExporter, asyncErrorChannel chan error) (sdkmetric.Reader, *http.Server, error) {

service/service_test.go

@@ -7,6 +7,7 @@ import (
  "bufio"
  "context"
  "errors"
+ "fmt"
  "net/http"
  "strings"
  "sync"
@@ -253,13 +254,16 @@ func TestServiceTelemetryCleanupOnError(t *testing.T) {
 
 func TestServiceTelemetry(t *testing.T) {
  for _, tc := range ownMetricsTestCases() {
- t.Run(tc.name, func(t *testing.T) {
- testCollectorStartHelper(t, tc)
+ t.Run(fmt.Sprintf("ipv4_%s", tc.name), func(t *testing.T) {
+ testCollectorStartHelper(t, tc, "tcp4")
+ })
+ t.Run(fmt.Sprintf("ipv6_%s", tc.name), func(t *testing.T) {
+ testCollectorStartHelper(t, tc, "tcp6")
  })
  }
 }
 
-func testCollectorStartHelper(t *testing.T, tc ownMetricsTestCase) {
+func testCollectorStartHelper(t *testing.T, tc ownMetricsTestCase, network string) {
  var once sync.Once
  loggingHookCalled := false
  hook := func(zapcore.Entry) error {
@@ -269,8 +273,20 @@ func testCollectorStartHelper(t *testing.T, tc ownMetricsTestCase) {
  return nil
  }
 
- metricsAddr := testutil.GetAvailableLocalAddress(t)
- zpagesAddr := testutil.GetAvailableLocalAddress(t)
+ var (
+ metricsAddr string
+ zpagesAddr string
+ )
+ switch network {
+ case "tcp", "tcp4":
+ metricsAddr = testutil.GetAvailableLocalAddress(t)
+ zpagesAddr = testutil.GetAvailableLocalAddress(t)
+ case "tcp6":
+ metricsAddr = testutil.GetAvailableLocalIPv6Address(t)
+ zpagesAddr = testutil.GetAvailableLocalIPv6Address(t)
+ }
+ require.NotZero(t, metricsAddr, "network must be either of tcp, tcp4 or tcp6")
+ require.NotZero(t, zpagesAddr, "network must be either of tcp, tcp4 or tcp6")
 
  set := newNopSettings()
  set.BuildInfo = component.BuildInfo{Version: "test version", Command: otelCommand}