[processor/resourcedetection] Disable host.id on system detector by default

.chloggen/mx-psi_system-detector-host-id.yaml

@@ -0,0 +1,30 @@
+# 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: breaking
+
+# 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: "Disable `host.id` by default on the `system` detector. This restores the behavior prior to v0.72.0 when using the `system` detector together with other detectors that set `host.id`"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [21233]
+
+# (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: |
+  To re-enable `host.id` on the `system` detector set `system::resource_attributes::host.id::enabled` to `true`:  
+
+  ```
+  resourcedetection:
+    detectors: [system]
+    system:
+      resource_attributes:
+        host.id:
+          enabled: true
+  ```

processor/resourcedetectionprocessor/README.md

@@ -515,8 +515,6 @@ resourcedetection:
         enabled: false
 ```
 
-NOTE: Currently all attributes are enabled by default for backwards compatibility purposes, but it will change in the future.
-
 ## Ordering
 
 Note that if multiple detectors are inserting the same attribute name, the first detector to insert wins. For example if you had `detectors: [eks, ec2]` then `cloud.platform` will be `aws_eks` instead of `ec2`. The below ordering is recommended.

processor/resourcedetectionprocessor/internal/system/metadata.yaml

@@ -10,8 +10,8 @@ resource_attributes:
   host.id:
     description: The host.id
     type: string
-    enabled: true
+    enabled: false
   os.type:
     description: The os.type
     type: string
-    enabled: true
+    enabled: true

processor/resourcedetectionprocessor/internal/system/system_test.go

@@ -98,7 +98,6 @@ func TestDetectFQDNAvailable(t *testing.T) {
 	expected := map[string]any{
 		conventions.AttributeHostName: "fqdn",
 		conventions.AttributeOSType:   "darwin",
-		conventions.AttributeHostID:   "2",
 	}
 
 	assert.Equal(t, expected, res.Attributes().AsRaw())
@@ -110,10 +109,32 @@ func TestFallbackHostname(t *testing.T) {
 	mdHostname.On("Hostname").Return("hostname", nil)
 	mdHostname.On("FQDN").Return("", errors.New("err"))
 	mdHostname.On("OSType").Return("darwin", nil)
+	mdHostname.On("HostID").Return("3", nil)
+
+	resourceAttributes := CreateDefaultConfig().ResourceAttributes
+	detector := &Detector{provider: mdHostname, logger: zap.NewNop(), hostnameSources: []string{"dns", "os"}, resourceAttributes: resourceAttributes}
+	res, schemaURL, err := detector.Detect(context.Background())
+	require.NoError(t, err)
+	assert.Equal(t, conventions.SchemaURL, schemaURL)
+	mdHostname.AssertExpectations(t)
+
+	expected := map[string]any{
+		conventions.AttributeHostName: "hostname",
+		conventions.AttributeOSType:   "darwin",
+	}
+
+	assert.Equal(t, expected, res.Attributes().AsRaw())
+}
+
+func TestEnableHostID(t *testing.T) {
+	mdHostname := &mockMetadata{}
+	mdHostname.On("Hostname").Return("hostname", nil)
+	mdHostname.On("FQDN").Return("", errors.New("err"))
 	mdHostname.On("OSType").Return("darwin", nil)
 	mdHostname.On("HostID").Return("3", nil)
 
 	resourceAttributes := CreateDefaultConfig().ResourceAttributes
+	resourceAttributes.HostID.Enabled = true
 	detector := &Detector{provider: mdHostname, logger: zap.NewNop(), hostnameSources: []string{"dns", "os"}, resourceAttributes: resourceAttributes}
 	res, schemaURL, err := detector.Detect(context.Background())
 	require.NoError(t, err)
@@ -145,7 +166,6 @@ func TestUseHostname(t *testing.T) {
 	expected := map[string]any{
 		conventions.AttributeHostName: "hostname",
 		conventions.AttributeOSType:   "darwin",
-		conventions.AttributeHostID:   "1",
 	}
 
 	assert.Equal(t, expected, res.Attributes().AsRaw())