feat(inputs.http_listener_v2): add unix socket mode

plugins/inputs/http_listener_v2/README.md

@@ -39,6 +39,17 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
   ## Address and port to host HTTP listener on
   service_address = ":8080"
 
+  ## Network type to listen to default tcp
+  # if set to unix service_address will be interpreted as unix socket path
+  # network = "tcp"
+
+  ## Permission for unix sockets (only available for network unix)
+  ## This setting may not be respected by some platforms. To safely restrict
+  ## permissions it is recommended to place the socket into a previously
+  ## created directory with the desired permissions.
+  ##   ex: socket_mode = "777"
+  # socket_mode = ""
+
   ## Paths to listen to.
   # paths = ["/telegraf"]
 

plugins/inputs/http_listener_v2/http_listener_v2.go

@@ -7,10 +7,15 @@ import (
 	"crypto/tls"
 	_ "embed"
 	"errors"
+	"fmt"
 	"io"
 	"net"
 	"net/http"
 	"net/url"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -47,6 +52,8 @@ type TimeFunc func() time.Time
 // HTTPListenerV2 is an input plugin that collects external metrics sent via HTTP
 type HTTPListenerV2 struct {
 	ServiceAddress string            `toml:"service_address"`
+	Network        string            `toml:"network"`
+	SocketMode     string            `toml:"socket_mode"`
 	Path           string            `toml:"path" deprecated:"1.20.0;1.35.0;use 'paths' instead"`
 	Paths          []string          `toml:"paths"`
 	PathTag        bool              `toml:"path_tag"`
@@ -151,18 +158,49 @@ func (h *HTTPListenerV2) Init() error {
 		return err
 	}
 
+	switch h.Network {
+	case "tcp":
+	case "unix":
+		path := filepath.FromSlash(h.ServiceAddress)
+		if runtime.GOOS == "windows" && strings.Contains(path, ":") {
+			path = strings.TrimPrefix(path, `\`)
+		}
+		if err := os.Remove(path); err != nil && !errors.Is(err, os.ErrNotExist) {
+			return fmt.Errorf("removing socket failed: %w", err)
+		}
+	default:
+		return fmt.Errorf("unknown protocol %q", h.Network)
+	}
+
 	var listener net.Listener
 	if tlsConf != nil {
-		listener, err = tls.Listen("tcp", h.ServiceAddress, tlsConf)
+		listener, err = tls.Listen(h.Network, h.ServiceAddress, tlsConf)
 	} else {
-		listener, err = net.Listen("tcp", h.ServiceAddress)
+		listener, err = net.Listen(h.Network, h.ServiceAddress)
 	}
 	if err != nil {
 		return err
 	}
 	h.tlsConf = tlsConf
 	h.listener = listener
-	h.Port = listener.Addr().(*net.TCPAddr).Port
+
+	if h.Network == "tcp" {
+		h.Port = listener.Addr().(*net.TCPAddr).Port
+	}
+
+	if h.Network == "unix" && h.SocketMode != "" {
+		// Set permissions on socket
+		// Convert from octal in string to int
+		i, err := strconv.ParseUint(h.SocketMode, 8, 32)
+		if err != nil {
+			return fmt.Errorf("converting socket mode failed: %w", err)
+		}
+
+		perm := os.FileMode(uint32(i))
+		if err := os.Chmod(h.ServiceAddress, perm); err != nil {
+			return fmt.Errorf("changing socket permissions failed: %w", err)
+		}
+	}
 
 	if h.SuccessCode == 0 {
 		h.SuccessCode = http.StatusNoContent
@@ -375,6 +413,7 @@ func init() {
 	inputs.Add("http_listener_v2", func() telegraf.Input {
 		return &HTTPListenerV2{
 			ServiceAddress: ":8080",
+			Network:        "tcp",
 			TimeFunc:       time.Now,
 			Paths:          []string{"/telegraf"},
 			Methods:        []string{"POST", "PUT"},

plugins/inputs/http_listener_v2/http_listener_v2_test.go

@@ -2,9 +2,11 @@ package http_listener_v2
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"crypto/x509"
 	"fmt"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -42,9 +44,7 @@ cpu_load_short,host=server06 value=12.0 1422568543702900257
 	basicPassword = "super-secure-password!"
 )
 
-var (
-	pki = testutil.NewPKI("../../../testutil/pki")
-)
+var pki = testutil.NewPKI("../../../testutil/pki")
 
 func newTestHTTPListenerV2() (*HTTPListenerV2, error) {
 	parser := &influx.Parser{}
@@ -54,6 +54,7 @@ func newTestHTTPListenerV2() (*HTTPListenerV2, error) {
 
 	listener := &HTTPListenerV2{
 		Log:            testutil.Logger{},
+		Network:        "tcp",
 		ServiceAddress: "localhost:0",
 		Path:           "/write",
 		Methods:        []string{"POST"},
@@ -84,6 +85,7 @@ func newTestHTTPSListenerV2() (*HTTPListenerV2, error) {
 
 	listener := &HTTPListenerV2{
 		Log:            testutil.Logger{},
+		Network:        "tcp",
 		ServiceAddress: "localhost:0",
 		Path:           "/write",
 		Methods:        []string{"POST"},
@@ -124,6 +126,7 @@ func TestInvalidListenerConfig(t *testing.T) {
 
 	listener := &HTTPListenerV2{
 		Log:            testutil.Logger{},
+		Network:        "tcp",
 		ServiceAddress: "address_without_port",
 		Path:           "/write",
 		Methods:        []string{"POST"},
@@ -231,8 +234,10 @@ func TestWriteHTTP(t *testing.T) {
 	require.EqualValues(t, 204, resp.StatusCode)
 
 	acc.Wait(2)
-	hostTags := []string{"server02", "server03",
-		"server04", "server05", "server06"}
+	hostTags := []string{
+		"server02", "server03",
+		"server04", "server05", "server06",
+	}
 	for _, hostTag := range hostTags {
 		acc.AssertContainsTaggedFields(t, "cpu_load_short",
 			map[string]interface{}{"value": float64(12)},
@@ -359,6 +364,7 @@ func TestWriteHTTPExactMaxBodySize(t *testing.T) {
 
 	listener := &HTTPListenerV2{
 		Log:            testutil.Logger{},
+		Network:        "tcp",
 		ServiceAddress: "localhost:0",
 		Path:           "/write",
 		Methods:        []string{"POST"},
@@ -385,6 +391,7 @@ func TestWriteHTTPVerySmallMaxBody(t *testing.T) {
 
 	listener := &HTTPListenerV2{
 		Log:            testutil.Logger{},
+		Network:        "tcp",
 		ServiceAddress: "localhost:0",
 		Path:           "/write",
 		Methods:        []string{"POST"},
@@ -429,8 +436,10 @@ func TestWriteHTTPGzippedData(t *testing.T) {
 	require.NoError(t, resp.Body.Close())
 	require.EqualValues(t, 204, resp.StatusCode)
 
-	hostTags := []string{"server02", "server03",
-		"server04", "server05", "server06"}
+	hostTags := []string{
+		"server02", "server03",
+		"server04", "server05", "server06",
+	}
 	acc.Wait(len(hostTags))
 	for _, hostTag := range hostTags {
 		acc.AssertContainsTaggedFields(t, "cpu_load_short",
@@ -724,6 +733,32 @@ func TestServerHeaders(t *testing.T) {
 	require.Equal(t, "value", resp.Header.Get("key"))
 }
 
+func TestUnixSocket(t *testing.T) {
+	listener, err := newTestHTTPListenerV2()
+	require.NoError(t, err)
+	listener.Network = "unix"
+	file, err := os.CreateTemp("", "*.socket")
+	require.NoError(t, err)
+	defer os.Remove(file.Name())
+	socketName := file.Name()
+	listener.ServiceAddress = socketName
+	listener.SocketMode = "777"
+	acc := &testutil.Accumulator{}
+	require.NoError(t, listener.Init())
+	require.NoError(t, listener.Start(acc))
+	httpc := http.Client{
+		Transport: &http.Transport{
+			DialContext: func(_ context.Context, _, _ string) (net.Conn, error) {
+				return net.Dial("unix", socketName)
+			},
+		},
+	}
+	resp, err := httpc.Post(createURL(listener, "http", "/write", "db=mydb"), "", bytes.NewBufferString(testMsg))
+	require.NoError(t, err)
+	require.NoError(t, resp.Body.Close())
+	require.EqualValues(t, 204, resp.StatusCode)
+}
+
 func mustReadHugeMetric() []byte {
 	filePath := "testdata/huge_metric"
 	data, err := os.ReadFile(filePath)

plugins/inputs/http_listener_v2/sample.conf

@@ -3,6 +3,17 @@
   ## Address and port to host HTTP listener on
   service_address = ":8080"
 
+  ## Network type to listen to default tcp
+  # if set to unix service_address will be interpreted as unix socket path
+  # network = "tcp"
+
+  ## Permission for unix sockets (only available for network unix)
+  ## This setting may not be respected by some platforms. To safely restrict
+  ## permissions it is recommended to place the socket into a previously
+  ## created directory with the desired permissions.
+  ##   ex: socket_mode = "777"
+  # socket_mode = ""
+
   ## Paths to listen to.
   # paths = ["/telegraf"]