[confighttp] support http+unix

.chloggen/unix-socket-support.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: confighttp
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Support http+unix scheme, for both client and HTTP servers.
+
+# One or more tracking issues or pull requests related to the change
+issues: [8752]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# 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: []

cmd/otelcorecol/go.mod

@@ -61,6 +61,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/mostynb/go-grpc-compression v1.2.2 // indirect
+	github.com/peterbourgon/unixtransport v0.0.3 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c // indirect
 	github.com/prometheus/client_golang v1.17.0 // indirect

config/confighttp/confighttp.go

@@ -6,11 +6,13 @@ package confighttp // import "go.opentelemetry.io/collector/config/confighttp"
 import (
 	"crypto/tls"
 	"errors"
+	"fmt"
 	"io"
 	"net"
 	"net/http"
 	"time"
 
+	"github.com/peterbourgon/unixtransport"
 	"github.com/rs/cors"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel"
@@ -189,6 +191,8 @@ func (hcs *HTTPClientSettings) ToClient(host component.Host, settings component.
 		}
 	}
 
+	unixtransport.Register(transport)
+
 	return &http.Client{
 		Transport: clientTransport,
 		Timeout:   hcs.Timeout,
@@ -215,6 +219,10 @@ type HTTPServerSettings struct {
 	// Endpoint configures the listening address for the server.
 	Endpoint string `mapstructure:"endpoint"`
 
+	// Network configures the network associated with the server.
+	// The network must be "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
+	Network string `mapstructure:"network"`
+
 	// TLSSetting struct exposes TLS client configuration.
 	TLSSetting *configtls.TLSServerSetting `mapstructure:"tls"`
 
@@ -238,7 +246,14 @@ type HTTPServerSettings struct {
 
 // ToListener creates a net.Listener.
 func (hss *HTTPServerSettings) ToListener() (net.Listener, error) {
-	listener, err := net.Listen("tcp", hss.Endpoint)
+	network := hss.Network
+	if network == "" {
+		network = "tcp"
+	}
+	if network == "http+unix" || network == "https+unix" || network == "unixpacket" {
+		network = "unix"
+	}
+	listener, err := net.Listen(network, hss.Endpoint)
 	if err != nil {
 		return nil, err
 	}
@@ -255,6 +270,15 @@ func (hss *HTTPServerSettings) ToListener() (net.Listener, error) {
 	return listener, nil
 }
 
+func (hss *HTTPServerSettings) Validate() error {
+	switch hss.Network {
+	case "tcp", "tcp4", "tcp6", "unix", "unixpacket", "http+unix", "https+unix", "":
+	default:
+		return fmt.Errorf("invalid network %q", hss.Network)
+	}
+	return nil
+}
+
 // toServerOptions has options that change the behavior of the HTTP server
 // returned by HTTPServerSettings.ToServer().
 type toServerOptions struct {

config/confighttp/confighttp_test.go

@@ -13,6 +13,7 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"path/filepath"
+	"runtime"
 	"testing"
 	"time"
 
@@ -1303,3 +1304,132 @@ func BenchmarkHttpRequest(b *testing.B) {
 		})
 	}
 }
+
+type recordingHandler struct {
+	requests []*http.Request
+}
+
+func (r *recordingHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
+	r.requests = append(r.requests, req)
+	resp.WriteHeader(200)
+}
+
+func TestUnixSocket(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("Skipping for Windows")
+	}
+	socketLocation := filepath.Join(t.TempDir(), "foo")
+	hss := &HTTPServerSettings{Endpoint: socketLocation, Network: "unix"}
+	handler := &recordingHandler{}
+	s, err := hss.ToServer(componenttest.NewNopHost(), componenttest.NewNopTelemetrySettings(), handler)
+	require.NoError(t, err)
+	l, err := hss.ToListener()
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		require.NoError(t, s.Close())
+	})
+	go func() {
+		_ = s.Serve(l)
+	}()
+	hcs := NewDefaultHTTPClientSettings()
+	hcs.Endpoint = fmt.Sprintf("http+unix:%s:/", socketLocation)
+	c, err := hcs.ToClient(componenttest.NewNopHost(), componenttest.NewNopTelemetrySettings())
+	require.NoError(t, err)
+	resp, err := c.Get(hcs.Endpoint)
+	require.NoError(t, err)
+	require.Equal(t, 200, resp.StatusCode)
+}
+
+func TestHTTPServerSettings_Validate(t *testing.T) {
+	unixSocket := filepath.Join(t.TempDir(), "socket")
+	tests := []struct {
+		name    string
+		hss     *HTTPServerSettings
+		wantErr error
+	}{
+		{
+			"default",
+			&HTTPServerSettings{
+				Endpoint: "localhost:0",
+			},
+			nil,
+		},
+		{
+			"tcp",
+			&HTTPServerSettings{
+				Network:  "tcp",
+				Endpoint: "localhost:0",
+			},
+			nil,
+		},
+		{
+			"tcp4",
+			&HTTPServerSettings{
+				Network:  "tcp4",
+				Endpoint: "localhost:0",
+			},
+			nil,
+		},
+		{
+			"tcp6",
+			&HTTPServerSettings{
+				Network:  "tcp6",
+				Endpoint: "localhost:0",
+			},
+			nil,
+		},
+		{
+			"unix",
+			&HTTPServerSettings{
+				Network:  "unix",
+				Endpoint: unixSocket,
+			},
+			nil,
+		},
+		{
+			"unixpacket",
+			&HTTPServerSettings{
+				Network:  "unixpacket",
+				Endpoint: unixSocket,
+			},
+			nil,
+		},
+		{
+			"http+unix",
+			&HTTPServerSettings{
+				Network:  "http+unix",
+				Endpoint: unixSocket,
+			},
+			nil,
+		},
+		{
+			"https+unix",
+			&HTTPServerSettings{
+				Network:  "https+unix",
+				Endpoint: unixSocket,
+			},
+			nil,
+		},
+		{
+			"invalid",
+			&HTTPServerSettings{
+				Network: "invalid",
+			},
+			errors.New("invalid network \"invalid\""),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.hss.Validate()
+			if tt.wantErr == nil {
+				assert.NoError(t, err)
+				l, err2 := tt.hss.ToListener()
+				assert.NoError(t, err2)
+				require.NoError(t, l.Close())
+			} else {
+				assert.Equal(t, tt.wantErr, err)
+			}
+		})
+	}
+}

config/confighttp/go.mod

@@ -5,6 +5,7 @@ go 1.20
 require (
 	github.com/golang/snappy v0.0.4
 	github.com/klauspost/compress v1.17.2
+	github.com/peterbourgon/unixtransport v0.0.3
 	github.com/rs/cors v1.10.1
 	github.com/stretchr/testify v1.8.4
 	go.opentelemetry.io/collector v0.88.0