feat(internal/metadataproviders/system): do not return empty host.id

.chloggen/drosiek-host-id.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# 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. filelogreceiver)
+component: resourcedetectionprocessor
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "avoid returning empty host.id on the `system` detector"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [24230]
+
+# (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:

internal/metadataproviders/go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/hashicorp/consul/api v1.22.0
 	github.com/stretchr/testify v1.8.4
 	go.opentelemetry.io/collector/semconv v0.81.0
+	go.opentelemetry.io/otel v1.16.0
 	go.opentelemetry.io/otel/sdk v1.16.0
 )
 
@@ -41,7 +42,6 @@ require (
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/stretchr/objx v0.5.0 // indirect
-	go.opentelemetry.io/otel v1.16.0 // indirect
 	go.opentelemetry.io/otel/metric v1.16.0 // indirect
 	go.opentelemetry.io/otel/trace v1.16.0 // indirect
 	golang.org/x/exp v0.0.0-20230321023759-10a507213a29 // indirect

internal/metadataproviders/system/metadata.go

@@ -60,10 +60,11 @@ type Provider interface {
 
 type systemMetadataProvider struct {
 	nameInfoProvider
+	newResource func(context.Context, ...resource.Option) (*resource.Resource, error)
 }
 
 func NewProvider() Provider {
-	return systemMetadataProvider{nameInfoProvider: newNameInfoProvider()}
+	return systemMetadataProvider{nameInfoProvider: newNameInfoProvider(), newResource: resource.New}
 }
 
 func (systemMetadataProvider) OSType() (string, error) {
@@ -120,7 +121,7 @@ func (p systemMetadataProvider) reverseLookup(ipAddresses []string) (string, err
 }
 
 func (p systemMetadataProvider) HostID(ctx context.Context) (string, error) {
-	res, err := resource.New(ctx,
+	res, err := p.newResource(ctx,
 		resource.WithHostID(),
 	)
 
@@ -132,7 +133,12 @@ func (p systemMetadataProvider) HostID(ctx context.Context) (string, error) {
 
 	for iter.Next() {
 		if iter.Attribute().Key == conventions.AttributeHostID {
-			return iter.Attribute().Value.Emit(), nil
+			v := iter.Attribute().Value.Emit()
+
+			if v == "" {
+				return "", fmt.Errorf("empty host id")
+			}
+			return v, nil
 		}
 	}
 

internal/metadataproviders/system/metadata_test.go

@@ -4,12 +4,15 @@
 package system
 
 import (
+	"context"
 	"fmt"
 	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 func TestLookupCNAME_Linux(t *testing.T) {
@@ -40,6 +43,65 @@ func TestReverseLookupHost_Windows(t *testing.T) {
 	assert.Equal(t, "my-windows-vm.abcdefghijklmnopqrstuvwxyz.xx.internal.foo.net", fqdn)
 }
 
+func TestHostID(t *testing.T) {
+	tests := []struct {
+		name         string
+		resValue     string
+		resError     error
+		fakeResource func(context.Context, ...resource.Option) (*resource.Resource, error)
+		err          string
+		expected     string
+	}{
+		{
+			name:     "valid host.id",
+			resValue: "my-linux-host-id",
+			resError: nil,
+			expected: "my-linux-host-id",
+		},
+		{
+			name:     "empty host.id",
+			resValue: "",
+			resError: nil,
+			err:      "failed to obtain host id",
+			expected: "",
+		},
+		{
+			name:     "error",
+			resValue: "",
+			resError: fmt.Errorf("some error"),
+			err:      "failed to obtain host id: some error",
+			expected: "",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			p := fakeLinuxSystemMetadataProvider()
+			p.newResource = func(ctx context.Context, o ...resource.Option) (*resource.Resource, error) {
+				if tt.resValue == "" {
+					return resource.NewSchemaless(), tt.resError
+				}
+
+				v := attribute.KeyValue{
+					Key:   "host.id",
+					Value: attribute.StringValue(tt.resValue),
+				}
+				ret := resource.NewSchemaless(v)
+
+				return ret, tt.resError
+			}
+			id, err := p.HostID(context.Background())
+
+			if tt.err != "" {
+				require.EqualError(t, err, tt.err)
+				return
+			}
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, id)
+		})
+	}
+}
+
 func fakeLinuxSystemMetadataProvider() *systemMetadataProvider {
 	return &systemMetadataProvider{
 		nameInfoProvider: fakeLinuxNameInfoProvider(),