Add a host resource detector

.github/dependabot.yml

@@ -172,6 +172,15 @@ updates:
     schedule:
       interval: weekly
       day: sunday
+  - package-ecosystem: gomod
+    directory: /detectors/host
+    labels:
+      - dependencies
+      - go
+      - Skip Changelog
+    schedule:
+      interval: weekly
+      day: sunday
   - package-ecosystem: gomod
     directory: /exporters/autoexport
     labels:

CHANGELOG.md

@@ -12,6 +12,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 - Add the new `go.opentelemetry.io/contrib/instrgen` package to provide auto-generated source code instrumentation. (#3068, #3108)
 - `NewSDK` in `go.opentelemetry.io/contrib/config` now returns a configured SDK with a valid `MeterProvider`. (#4804)
+- Add the new `go.opentelemetry.io/contrib/detectors/host` package to provide a resource detector for physical hosts. (#5399)
 
 ### Fixed
 

detectors/host/README.md

@@ -0,0 +1,35 @@
+# Host Resource detector
+
+The host resource detector supports detecting host-specific attributes on physical hosts.
+
+## Usage
+
+```golang
+// Instantiate a new host resource detector
+hostResourceDetector := host.NewResourceDetector()
+resource, err := hostResourceDetector.Detect(context.Background())
+```
+
+To populate optional attributes, the resource detector constructor accepts functional options `WithIPAddresses` to enable `host.ip`, and `WithMACAddresses` to enable `host.mac`.
+
+```golang
+// Instantiate a new host resource detector with all opt-in attributes
+hostResourceDetector := host.NewResourceDetector(
+	WithIPAddresses(),
+	WithMACAddresses(),
+)
+resource, err := hostResourceDetector.Detect(context.Background())
+```
+
+## Supported attributes
+
+According to [semantic conventions for host resources](https://github.com/open-telemetry/semantic-conventions/blob/main/docs/resource/host.md), each of the following attributes is added if it is available:
+
+* `host.arch`
+* `host.id`
+* `host.name`
+
+The following attributes require an explicit opt-in during the initialization of the host resource detector:
+
+* `host.ip`
+* `host.mac`

detectors/host/go.mod

@@ -0,0 +1,20 @@
+module go.opentelemetry.io/contrib/detectors/host
+
+go 1.21
+
+require (
+	github.com/stretchr/testify v1.9.0
+	go.opentelemetry.io/otel v1.25.0
+	go.opentelemetry.io/otel/sdk v1.25.0
+	golang.org/x/sys v0.18.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/otel/metric v1.25.0 // indirect
+	go.opentelemetry.io/otel/trace v1.25.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

detectors/host/go.sum

@@ -0,0 +1,27 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
+github.com/go-logr/logr v1.4.1 h1:pKouT5E8xu9zeFC39JXRDukb6JFQPXM5p5I91188VAQ=
+github.com/go-logr/logr v1.4.1/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+go.opentelemetry.io/otel v1.25.0 h1:gldB5FfhRl7OJQbUHt/8s0a7cE8fbsPAtdpRaApKy4k=
+go.opentelemetry.io/otel v1.25.0/go.mod h1:Wa2ds5NOXEMkCmUou1WA7ZBfLTHWIsp034OVD7AO+Vg=
+go.opentelemetry.io/otel/metric v1.25.0 h1:LUKbS7ArpFL/I2jJHdJcqMGxkRdxpPHE0VU/D4NuEwA=
+go.opentelemetry.io/otel/metric v1.25.0/go.mod h1:rkDLUSd2lC5lq2dFNrX9LGAbINP5B7WBkC78RXCpH5s=
+go.opentelemetry.io/otel/sdk v1.25.0 h1:PDryEJPC8YJZQSyLY5eqLeafHtG+X7FWnf3aXMtxbqo=
+go.opentelemetry.io/otel/sdk v1.25.0/go.mod h1:oFgzCM2zdsxKzz6zwpTZYLLQsFwc+K0daArPdIhuxkw=
+go.opentelemetry.io/otel/trace v1.25.0 h1:tqukZGLwQYRIFtSQM2u2+yfMVTgGVeqRLPUYx1Dq6RM=
+go.opentelemetry.io/otel/trace v1.25.0/go.mod h1:hCCs70XM/ljO+BeQkyFnbK28SBIJ/Emuha+ccrCRT7I=
+golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
+golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

detectors/host/host.go

@@ -0,0 +1,137 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package host // import "go.opentelemetry.io/contrib/detectors/host"
+
+import (
+	"context"
+	"net"
+	"os"
+	"runtime"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/resource"
+	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+)
+
+type config struct {
+	optInIPAddresses  bool
+	optInMACAddresses bool
+}
+
+func newConfig(options ...Option) *config {
+	c := &config{}
+	for _, option := range options {
+		option.apply(c)
+	}
+
+	return c
+}
+
+// Option applies an Azure VM detector configuration option.
+type Option interface {
+	apply(*config)
+}
+
+type optionFunc func(*config)
+
+func (fn optionFunc) apply(c *config) {
+	fn(c)
+}
+
+// WithIPAddresses adds the optional attribute `host.ip`.
+func WithIPAddresses() Option {
+	return optionFunc(func(c *config) {
+		c.optInIPAddresses = true
+	})
+}
+
+// WithMACAddresses adds the optional attribute `host.ip`.
+func WithMACAddresses() Option {
+	return optionFunc(func(c *config) {
+		c.optInMACAddresses = true
+	})
+}
+
+type resourceDetector struct {
+	config *config
+}
+
+// NewResourceDetector returns a resource detector that will detect host resources.
+func NewResourceDetector(opts ...Option) resource.Detector {
+	c := newConfig(opts...)
+	return &resourceDetector{config: c}
+}
+
+// Detect detects associated resources when running on a physical host.
+func (detector *resourceDetector) Detect(ctx context.Context) (*resource.Resource, error) {
+	attributes := []attribute.KeyValue{
+		semconv.HostArchKey.String(runtime.GOARCH),
+	}
+
+	hostName, err := os.Hostname()
+	if err == nil {
+		attributes = append(attributes, semconv.HostName(hostName))
+	}
+
+	machineId, err := getHostId()
+	if err == nil {
+		attributes = append(attributes, semconv.HostID(machineId))
+	}
+
+	if detector.config.optInIPAddresses {
+		ipAddresses := getIPAddresses()
+		if len(ipAddresses) > 0 {
+			attributes = append(attributes, semconv.HostIP(ipAddresses...))
+		}
+	}
+
+	if detector.config.optInMACAddresses {
+		macAddresses := getMACAddresses()
+		if len(macAddresses) > 0 {
+			attributes = append(attributes, semconv.HostMac(macAddresses...))
+		}
+	}
+
+	return resource.NewWithAttributes(semconv.SchemaURL, attributes...), nil
+}
+
+func getIPAddresses() []string {
+	var ipAddresses []string
+
+	ifaces, err := net.Interfaces()
+	if err == nil {
+		for _, iface := range ifaces {
+			if iface.Flags&net.FlagLoopback != 0 {
+				continue
+			}
+
+			addrs, err := iface.Addrs()
+			if err != nil {
+				continue
+			}
+			for _, addr := range addrs {
+				ipAddresses = append(ipAddresses, addr.String())
+			}
+		}
+	}
+
+	return ipAddresses
+}
+
+func getMACAddresses() []string {
+	var macAddresses []string
+
+	ifaces, err := net.Interfaces()
+	if err == nil {
+		for _, iface := range ifaces {
+			if iface.Flags&net.FlagLoopback != 0 {
+				continue
+			}
+
+			macAddresses = append(macAddresses, iface.HardwareAddr.String())
+		}
+	}
+
+	return macAddresses
+}

detectors/host/host_id_darwin.go

@@ -0,0 +1,21 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build darwin
+// +build darwin
+
+package host // import "go.opentelemetry.io/contrib/detectors/host"
+
+import (
+	"os/exec"
+	"strings"
+)
+
+func getHostId() (string, error) {
+	machineId, err := exec.Command("ioreg", "-rd1", "-c", "IOPlatformExpertDevice").Output()
+	if err != nil {
+		return "", err
+	}
+
+	return strings.Trim(string(machineId), "\n"), nil
+}

detectors/host/host_id_linux.go

@@ -0,0 +1,21 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build linux
+// +build linux
+
+package host // import "go.opentelemetry.io/contrib/detectors/host"
+
+import (
+	"os"
+	"strings"
+)
+
+func getHostId() (string, error) {
+	machineId, err := os.ReadFile("/etc/machine-id")
+	if err != nil {
+		return "", err
+	}
+
+	return strings.Trim(string(machineId), "\n"), nil
+}

detectors/host/host_id_windows.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build windows
+// +build windows
+
+package host // import "go.opentelemetry.io/contrib/detectors/host"
+
+import (
+	"golang.org/x/sys/windows/registry"
+)
+
+func getHostId() (string, error) {
+	key, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Cryptography`, registry.QUERY_VALUE)
+	if err != nil {
+		return "", err
+	}
+
+	defer key.Close()
+
+	machineId, _, err := key.GetStringValue("MachineGuid")
+
+	return machineId, err
+}

detectors/host/host_test.go

@@ -0,0 +1,73 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package host
+
+import (
+	"context"
+	"os"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/resource"
+	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+)
+
+func Test_Detect(t *testing.T) {
+	detector := NewResourceDetector()
+
+	hostResource, err := detector.Detect(context.Background())
+
+	assert.True(t, err == nil)
+
+	hostName, _ := os.Hostname()
+
+	attributes := []attribute.KeyValue{
+		semconv.HostArchKey.String(runtime.GOARCH),
+		semconv.HostName(hostName),
+	}
+
+	// The host id is added conditionally, as it might not be available under all circumstances (for example in Windows containers)
+	machineId, err := getHostId()
+	if err == nil {
+		attributes = append(attributes, semconv.HostID(machineId))
+	}
+
+	expectedResource := resource.NewWithAttributes(semconv.SchemaURL, attributes...)
+
+	assert.Equal(t, expectedResource, hostResource)
+}
+
+func Test_Detect_WithOptIns(t *testing.T) {
+	detector := NewResourceDetector(
+		WithIPAddresses(),
+		WithMACAddresses(),
+	)
+
+	hostResource, err := detector.Detect(context.Background())
+
+	assert.True(t, err == nil)
+
+	hostName, _ := os.Hostname()
+
+	attributes := []attribute.KeyValue{
+		semconv.HostArchKey.String(runtime.GOARCH),
+		semconv.HostName(hostName),
+	}
+
+	// The host id is added conditionally, as it might not be available under all circumstances (for example in Windows containers)
+	machineId, err := getHostId()
+	if err == nil {
+		attributes = append(attributes, semconv.HostID(machineId))
+	}
+
+	attributes = append(attributes, semconv.HostIP(getIPAddresses()...))
+	attributes = append(attributes, semconv.HostMac(getMACAddresses()...))
+
+	expectedResource := resource.NewWithAttributes(semconv.SchemaURL, attributes...)
+
+	assert.Equal(t, expectedResource, hostResource)
+}