[processor/resourcedetection] Add fail_on_missing_metadata to EC2 det…

…ector (#37453)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
Add `fail_on_missing_metadata` option on EC2 detector

If the EC2 metadata endpoint is unavailable, the EC2 detector by default
ignores the error.
By setting `fail_on_missing_metadata` to true on the detector, the user
will now trigger an error explicitly,
which will stop the collector from starting.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Relates to #35936

.chloggen/ec2_fail_on_missing_metadata.yaml

@@ -0,0 +1,30 @@
+# 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: resourcedetectionprocessor
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add `fail_on_missing_metadata` option on EC2 detector
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35936]
+
+# (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: |
+  If the EC2 metadata endpoint is unavailable, the EC2 detector by default ignores the error.
+  By setting `fail_on_missing_metadata` to true on the detector, the user will now trigger an error explicitly,
+  which will stop the collector from starting.
+
+# 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: []

processor/resourcedetectionprocessor/README.md

@@ -253,6 +253,7 @@ In some cases, you might need to change the behavior of the AWS metadata client
 By default, the client retries 3 times with a max backoff delay of 20s.
 
 We offer a limited set of options to override those defaults specifically, such that you can set the client to retry 10 times, for up to 5 minutes, for example:
+
 ```yaml
 processors:
   resourcedetection/ec2:
@@ -262,6 +263,16 @@ processors:
       max_backoff: 5m
 ```
 
+The EC2 detector will report an error in logs if the EC2 metadata endpoint is unavailable. You can configure the detector to instead fail with this flag:
+
+```yaml
+processors:
+  resourcedetection/ec2:
+    detectors: ["ec2"]
+    ec2:
+      fail_on_missing_metadata: true
+```
+
 ### Amazon ECS
 
 Queries the [Task Metadata Endpoint](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task-metadata-endpoint.html) (TMDE) to record information about the current ECS Task. Only TMDE V4 and V3 are supported.

processor/resourcedetectionprocessor/internal/aws/ec2/config.go

@@ -15,10 +15,11 @@ import (
 type Config struct {
 	// Tags is a list of regex's to match ec2 instance tag keys that users want
 	// to add as resource attributes to processed data
-	Tags               []string                          `mapstructure:"tags"`
-	ResourceAttributes metadata.ResourceAttributesConfig `mapstructure:"resource_attributes"`
-	MaxAttempts        int                               `mapstructure:"max_attempts"`
-	MaxBackoff         time.Duration                     `mapstructure:"max_backoff"`
+	Tags                  []string                          `mapstructure:"tags"`
+	ResourceAttributes    metadata.ResourceAttributesConfig `mapstructure:"resource_attributes"`
+	MaxAttempts           int                               `mapstructure:"max_attempts"`
+	MaxBackoff            time.Duration                     `mapstructure:"max_backoff"`
+	FailOnMissingMetadata bool                              `mapstructure:"fail_on_missing_metadata"`
 }
 
 func CreateDefaultConfig() Config {

processor/resourcedetectionprocessor/internal/aws/ec2/ec2.go

@@ -51,11 +51,12 @@ func (e *ec2ClientBuilder) buildClient(ctx context.Context, region string, clien
 }
 
 type Detector struct {
-	metadataProvider ec2provider.Provider
-	tagKeyRegexes    []*regexp.Regexp
-	logger           *zap.Logger
-	rb               *metadata.ResourceBuilder
-	ec2ClientBuilder ec2ifaceBuilder
+	metadataProvider      ec2provider.Provider
+	tagKeyRegexes         []*regexp.Regexp
+	logger                *zap.Logger
+	rb                    *metadata.ResourceBuilder
+	ec2ClientBuilder      ec2ifaceBuilder
+	failOnMissingMetadata bool
 }
 
 func NewDetector(set processor.Settings, dcfg internal.DetectorConfig) (internal.Detector, error) {
@@ -76,17 +77,21 @@ func NewDetector(set processor.Settings, dcfg internal.DetectorConfig) (internal
 	}
 
 	return &Detector{
-		metadataProvider: ec2provider.NewProvider(awsConfig),
-		tagKeyRegexes:    tagKeyRegexes,
-		logger:           set.Logger,
-		rb:               metadata.NewResourceBuilder(cfg.ResourceAttributes),
-		ec2ClientBuilder: &ec2ClientBuilder{},
+		metadataProvider:      ec2provider.NewProvider(awsConfig),
+		tagKeyRegexes:         tagKeyRegexes,
+		logger:                set.Logger,
+		rb:                    metadata.NewResourceBuilder(cfg.ResourceAttributes),
+		ec2ClientBuilder:      &ec2ClientBuilder{},
+		failOnMissingMetadata: cfg.FailOnMissingMetadata,
 	}, nil
 }
 
 func (d *Detector) Detect(ctx context.Context) (resource pcommon.Resource, schemaURL string, err error) {
 	if _, err = d.metadataProvider.InstanceID(ctx); err != nil {
 		d.logger.Debug("EC2 metadata unavailable", zap.Error(err))
+		if d.failOnMissingMetadata {
+			return pcommon.NewResource(), "", err
+		}
 		return pcommon.NewResource(), "", nil
 	}
 

processor/resourcedetectionprocessor/internal/aws/ec2/ec2_test.go

@@ -153,13 +153,14 @@ func TestDetector_Detect(t *testing.T) {
 		ctx context.Context
 	}
 	tests := []struct {
-		name          string
-		fields        fields
-		tagKeyRegexes []*regexp.Regexp
-		args          args
-		want          pcommon.Resource
-		wantErr       bool
-		tagsProvider  ec2ifaceBuilder
+		name                  string
+		fields                fields
+		tagKeyRegexes         []*regexp.Regexp
+		args                  args
+		want                  pcommon.Resource
+		wantErr               bool
+		tagsProvider          ec2ifaceBuilder
+		failOnMissingMetadata bool
 	}{
 		{
 			name: "success",
@@ -267,6 +268,18 @@ func TestDetector_Detect(t *testing.T) {
 			want:    pcommon.NewResource(),
 			wantErr: false,
 		},
+		{
+			name: "endpoint not available, with fail_on_missing_metadata",
+			fields: fields{metadataProvider: &mockMetadata{
+				retIDDoc:    imds.InstanceIdentityDocument{},
+				retErrIDDoc: errors.New("should not be called"),
+				isAvailable: false,
+			}},
+			args:                  args{ctx: context.Background()},
+			want:                  pcommon.NewResource(),
+			wantErr:               true,
+			failOnMissingMetadata: true,
+		},
 		{
 			name: "get fails",
 			fields: fields{metadataProvider: &mockMetadata{
@@ -294,11 +307,12 @@ func TestDetector_Detect(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			d := &Detector{
-				metadataProvider: tt.fields.metadataProvider,
-				logger:           zap.NewNop(),
-				rb:               metadata.NewResourceBuilder(metadata.DefaultResourceAttributesConfig()),
-				tagKeyRegexes:    tt.tagKeyRegexes,
-				ec2ClientBuilder: tt.tagsProvider,
+				metadataProvider:      tt.fields.metadataProvider,
+				logger:                zap.NewNop(),
+				rb:                    metadata.NewResourceBuilder(metadata.DefaultResourceAttributesConfig()),
+				tagKeyRegexes:         tt.tagKeyRegexes,
+				ec2ClientBuilder:      tt.tagsProvider,
+				failOnMissingMetadata: tt.failOnMissingMetadata,
 			}
 			got, _, err := d.Detect(tt.args.ctx)