[processor/resource][processor/attributes] Option to read client addr…

…ess (open-telemetry#34048)

We have options to extract headers and auth info from the client. This
change adds an option to extract client address by specifying
`client.address` value in the `from_context` field.

The code to extract address from the client info is taken from the
k8sattributes receiver.

Fixes
open-telemetry#34051

---------

Co-authored-by: Curtis Robert <crobert@splunk.com>

.chloggen/attribute-from-client-address.yaml

@@ -0,0 +1,22 @@
+# 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. filelogreceiver)
+component: processor/resource, processor/attributes
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add an option to extract value from a client address by specifying `client.address` value in the `from_context` field.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [34051]
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# 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/coreinternal/attraction/attraction.go

@@ -12,6 +12,8 @@ import (
 	"go.opentelemetry.io/collector/client"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.uber.org/zap"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal/clientutil"
 )
 
 // Settings specifies the processor settings.
@@ -341,14 +343,17 @@ func (ap *AttrProc) Process(ctx context.Context, logger *zap.Logger, attrs pcomm
 
 func getAttributeValueFromContext(ctx context.Context, key string) (pcommon.Value, bool) {
 	const (
-		metadataPrefix = "metadata."
-		authPrefix     = "auth."
+		metadataPrefix   = "metadata."
+		authPrefix       = "auth."
+		clientAddressKey = "client.address"
 	)
 
 	ci := client.FromContext(ctx)
 	var vals []string
 
 	switch {
+	case key == clientAddressKey:
+		vals = []string{clientutil.Address(ci)}
 	case strings.HasPrefix(key, metadataPrefix):
 		mdKey := strings.TrimPrefix(key, metadataPrefix)
 		vals = ci.Metadata.Get(mdKey)

internal/coreinternal/attraction/attraction_test.go

@@ -10,6 +10,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"net"
 	"regexp"
 	"testing"
 
@@ -958,6 +959,9 @@ func TestFromContext(t *testing.T) {
 		Auth: mockInfoAuth{
 			"source_auth_val": "auth_val",
 		},
+		Addr: &net.IPAddr{
+			IP: net.IPv4(192, 168, 1, 1),
+		},
 	})
 
 	testCases := []struct {
@@ -1008,6 +1012,12 @@ func TestFromContext(t *testing.T) {
 			expectedAttributes: map[string]any{},
 			action:             &ActionKeyValue{Key: "dest", FromContext: "auth.unknown_val", Action: INSERT},
 		},
+		{
+			name:               "with_address",
+			ctx:                mdCtx,
+			expectedAttributes: map[string]any{"dest": "192.168.1.1"},
+			action:             &ActionKeyValue{Key: "dest", FromContext: "client.address", Action: INSERT},
+		},
 	}
 
 	for _, tc := range testCases {

internal/coreinternal/clientutil/client.go

@@ -0,0 +1,40 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package clientutil // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal/clientutil"
+
+import (
+	"net"
+	"strings"
+
+	"go.opentelemetry.io/collector/client"
+)
+
+// Address returns the address of the client connecting to the collector.
+func Address(client client.Info) string {
+	if client.Addr == nil {
+		return ""
+	}
+	switch addr := client.Addr.(type) {
+	case *net.UDPAddr:
+		return addr.IP.String()
+	case *net.TCPAddr:
+		return addr.IP.String()
+	case *net.IPAddr:
+		return addr.IP.String()
+	}
+
+	// If this is not a known address type, check for known "untyped" formats.
+	// 1.1.1.1:<port>
+
+	lastColonIndex := strings.LastIndex(client.Addr.String(), ":")
+	if lastColonIndex != -1 {
+		ipString := client.Addr.String()[:lastColonIndex]
+		ip := net.ParseIP(ipString)
+		if ip != nil {
+			return ip.String()
+		}
+	}
+
+	return client.Addr.String()
+}

internal/coreinternal/clientutil/client_test.go

@@ -0,0 +1,79 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package clientutil
+
+import (
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/collector/client"
+)
+
+type fakeAddr string
+
+func (s fakeAddr) String() string {
+	return string(s)
+}
+
+func (fakeAddr) Network() string {
+	return "tcp"
+}
+
+func TestAddress(t *testing.T) {
+	tests := []struct {
+		name   string
+		client client.Info
+		want   string
+	}{
+		{
+			name: "UDPAddr",
+			client: client.Info{
+				Addr: &net.UDPAddr{
+					IP:   net.IPv4(192, 0, 2, 1),
+					Port: 1234,
+				},
+			},
+			want: "192.0.2.1",
+		},
+		{
+			name: "TCPAddr",
+			client: client.Info{
+				Addr: &net.TCPAddr{
+					IP:   net.IPv4(192, 0, 2, 2),
+					Port: 1234,
+				},
+			},
+			want: "192.0.2.2",
+		},
+		{
+			name: "IPAddr",
+			client: client.Info{
+				Addr: &net.IPAddr{
+					IP: net.IPv4(192, 0, 2, 3),
+				},
+			},
+			want: "192.0.2.3",
+		},
+		{
+			name: "fake_addr_with_port",
+			client: client.Info{
+				Addr: fakeAddr("1.1.1.1:3200"),
+			},
+			want: "1.1.1.1",
+		},
+		{
+			name: "fake_addr_without_port",
+			client: client.Info{
+				Addr: fakeAddr("1.1.1.1"),
+			},
+			want: "1.1.1.1",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, Address(tt.client))
+		})
+	}
+}

processor/attributesprocessor/README.md

@@ -61,8 +61,9 @@ For the actions `insert`, `update` and `upsert`,
   # If the key is prefixed with `metadata.`, the values are searched
   # in the receiver's transport protocol additional information like gRPC Metadata or HTTP Headers. 
   # If the key is prefixed with `auth.`, the values are searched
-  # in the authentication information set by the server authenticator. 
+  # in the authentication information set by the server authenticator.
   # Refer to the server authenticator's documentation part of your pipeline for more information about which attributes are available.
+  # If the key is `client.address`, the value will be set to the client address. 
   # If the key doesn't exist, no action is performed.
   # If the key has multiple values the values will be joined with `;` separator.
   from_context: <other key>

processor/k8sattributesprocessor/go.mod

@@ -5,6 +5,7 @@ go 1.21.0
 require (
 	github.com/google/go-cmp v0.6.0
 	github.com/google/uuid v1.6.0
+	github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal v0.0.0-00010101000000-000000000000
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8sconfig v0.104.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8stest v0.104.0
 	github.com/stretchr/testify v1.9.0
@@ -132,7 +133,15 @@ retract (
 	v0.65.0
 )
 
+replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal => ../../internal/coreinternal
+
 replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8stest => ../../internal/k8stest
 
 // ambiguous import: found package cloud.google.com/go/compute/metadata in multiple modules
 replace cloud.google.com/go v0.54.0 => cloud.google.com/go v0.110.10
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil => ../../pkg/pdatautil
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatatest => ../../pkg/pdatatest
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden => ../../pkg/golden

processor/k8sattributesprocessor/pod_association.go

@@ -6,12 +6,12 @@ package k8sattributesprocessor // import "github.com/open-telemetry/opentelemetr
 import (
 	"context"
 	"net"
-	"strings"
 
 	"go.opentelemetry.io/collector/client"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	conventions "go.opentelemetry.io/collector/semconv/v1.6.1"
 
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal/clientutil"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/k8sattributesprocessor/internal/kube"
 )
 
@@ -22,7 +22,7 @@ func extractPodID(ctx context.Context, attrs pcommon.Map, associations []kube.As
 		return extractPodIDNoAssociations(ctx, attrs)
 	}
 
-	connectionIP := connectionIP(ctx)
+	connectionIP := clientutil.Address(client.FromContext(ctx))
 	for _, asso := range associations {
 		skip := false
 
@@ -81,7 +81,7 @@ func extractPodIDNoAssociations(ctx context.Context, attrs pcommon.Map) kube.Pod
 		}
 	}
 
-	connectionIP := connectionIP(ctx)
+	connectionIP := clientutil.Address(client.FromContext(ctx))
 	if connectionIP != "" {
 		return kube.PodIdentifier{
 			kube.PodIdentifierAttributeFromConnection(connectionIP),
@@ -98,36 +98,6 @@ func extractPodIDNoAssociations(ctx context.Context, attrs pcommon.Map) kube.Pod
 	return kube.PodIdentifier{}
 }
 
-func connectionIP(ctx context.Context) string {
-	c := client.FromContext(ctx)
-	if c.Addr == nil {
-		return ""
-	}
-	switch addr := c.Addr.(type) {
-	case *net.UDPAddr:
-		return addr.IP.String()
-	case *net.TCPAddr:
-		return addr.IP.String()
-	case *net.IPAddr:
-		return addr.IP.String()
-	}
-
-	// If this is not a known address type, check for known "untyped" formats.
-	// 1.1.1.1:<port>
-
-	lastColonIndex := strings.LastIndex(c.Addr.String(), ":")
-	if lastColonIndex != -1 {
-		ipString := c.Addr.String()[:lastColonIndex]
-		ip := net.ParseIP(ipString)
-		if ip != nil {
-			return ip.String()
-		}
-	}
-
-	return c.Addr.String()
-
-}
-
 func stringAttributeFromMap(attrs pcommon.Map, key string) string {
 	if val, ok := attrs.Get(key); ok {
 		if val.Type() == pcommon.ValueTypeStr {