[mdatagen] allow filtering out metrics based on resource attributes

.chloggen/mdatagen-filter.yaml

@@ -0,0 +1,25 @@
+# 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. otlpreceiver)
+component: "cmd/metadatagen"
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "support excluding some metrics based on string and regexes in resource_attributes"
+
+# One or more tracking issues or pull requests related to the change
+issues: [9661]
+
+# (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:
+
+# 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]

cmd/mdatagen/go.mod

@@ -8,6 +8,7 @@ require (
 	go.opentelemetry.io/collector/component v0.95.0
 	go.opentelemetry.io/collector/confmap v0.95.0
 	go.opentelemetry.io/collector/confmap/provider/fileprovider v0.95.0
+	go.opentelemetry.io/collector/filter v0.0.0-00010101000000-000000000000
 	go.opentelemetry.io/collector/pdata v1.2.0
 	go.opentelemetry.io/collector/receiver v0.95.0
 	go.opentelemetry.io/collector/semconv v0.95.0
@@ -70,6 +71,8 @@ replace go.opentelemetry.io/collector/featuregate => ../../featuregate
 
 replace go.opentelemetry.io/collector/consumer => ../../consumer
 
+replace go.opentelemetry.io/collector/filter => ../../filter
+
 replace go.opentelemetry.io/collector => ../..
 
 replace go.opentelemetry.io/collector/config/configtelemetry => ../../config/configtelemetry

cmd/mdatagen/loader.go

@@ -13,6 +13,7 @@ import (
 
 	"go.opentelemetry.io/collector/confmap"
 	"go.opentelemetry.io/collector/confmap/provider/fileprovider"
+	"go.opentelemetry.io/collector/filter"
 	"go.opentelemetry.io/collector/pdata/pcommon"
 )
 
@@ -156,6 +157,10 @@ type attribute struct {
 	NameOverride string `mapstructure:"name_override"`
 	// Enabled defines whether the attribute is enabled by default.
 	Enabled bool `mapstructure:"enabled"`
+	// Include can be used to filter attributes.
+	Include []filter.Config `mapstructure:"include"`
+	// Include can be used to filter attributes.
+	Exclude []filter.Config `mapstructure:"exclude"`
 	// Enum can optionally describe the set of values to which the attribute can belong.
 	Enum []string `mapstructure:"enum"`
 	// Type is an attribute type.

cmd/mdatagen/templates/config.go.tmpl

@@ -5,7 +5,9 @@ package {{ .Package }}
 {{ if or .Metrics .ResourceAttributes -}}
 import "go.opentelemetry.io/collector/confmap"
 {{- end }}
-
+{{ if .ResourceAttributes -}}
+import "go.opentelemetry.io/collector/filter"
+{{- end }}
 {{ if .Metrics -}}
 
 // MetricConfig provides common config for a particular metric.
@@ -49,6 +51,8 @@ func DefaultMetricsConfig() MetricsConfig {
 // ResourceAttributeConfig provides common config for a particular resource attribute.
 type ResourceAttributeConfig struct {
 	Enabled bool `mapstructure:"enabled"`
+	Include []filter.Config `mapstructure:"include"`
+	Exclude []filter.Config `mapstructure:"exclude"`
 
 	enabledSetByUser bool
 }

cmd/mdatagen/templates/metrics.go.tmpl

@@ -16,6 +16,9 @@ import (
 	{{- if .SemConvVersion }}
 	conventions "go.opentelemetry.io/collector/semconv/v{{ .SemConvVersion }}"
 	{{- end }}
+	{{ if .ResourceAttributes -}}
+	"go.opentelemetry.io/collector/filter"
+	{{- end }}
 )
 
 {{ range $name, $info := .Attributes }}
@@ -132,6 +135,10 @@ type MetricsBuilder struct {
 	metricsCapacity int                  // maximum observed number of metrics per resource.
 	metricsBuffer   pmetric.Metrics      // accumulates metrics data before emitting.
 	buildInfo       component.BuildInfo  // contains version information.
+	{{ if .ResourceAttributes -}}
+	resourceAttributeIncludeFilter map[string]filter.Filter
+	resourceAttributeExcludeFilter map[string]filter.Filter
+	{{- end }}
 	{{- range $name, $metric := .Metrics }}
 	metric{{ $name.Render }} metric{{ $name.Render }}
 	{{- end }}
@@ -190,7 +197,20 @@ func NewMetricsBuilder(mbc MetricsBuilderConfig, settings receiver.CreateSetting
 		{{- range $name, $metric := .Metrics }}
 		metric{{ $name.Render }}: newMetric{{ $name.Render }}(mbc.Metrics.{{ $name.Render }}),
 		{{- end }}
+		{{ if .ResourceAttributes -}}
+		resourceAttributeIncludeFilter: make(map[string]filter.Filter),
+		resourceAttributeExcludeFilter: make(map[string]filter.Filter),
+		{{- end }}
+	}
+	{{- range $name, $attr := .ResourceAttributes }}
+	if mbc.ResourceAttributes.{{ $name.Render }}.Include != nil {
+		mb.resourceAttributeIncludeFilter["{{ $name }}"] = filter.CreateFilter(mbc.ResourceAttributes.{{ $name.Render }}.Include)
+	}
+	if mbc.ResourceAttributes.{{ $name.Render }}.Exclude != nil {
+		mb.resourceAttributeExcludeFilter["{{ $name }}"] = filter.CreateFilter(mbc.ResourceAttributes.{{ $name.Render }}.Exclude)
 	}
+	{{- end }}
+
 	for _, op := range options {
 		op(mb)
 	}
@@ -263,6 +283,21 @@ func (mb *MetricsBuilder) EmitForResource(rmo ...ResourceMetricsOption) {
 	for _, op := range rmo {
 		op(rm)
 	}
+	{{ if .ResourceAttributes -}}
+	for name, val := range rm.Resource().Attributes().AsRaw() {
+		if filter, ok := mb.resourceAttributeIncludeFilter[name]; ok {
+			if !filter.Matches(val) {
+				return
+			}
+		}
+		if filter, ok := mb.resourceAttributeExcludeFilter[name]; ok {
+			if filter.Matches(val) {
+				return
+			}
+		}
+	}
+	{{- end }}
+
 	if ils.Metrics().Len() > 0 {
 		mb.updateCapacity(rm)
 		rm.MoveTo(mb.metricsBuffer.ResourceMetrics().AppendEmpty())

filter/Makefile

@@ -0,0 +1 @@
+include ../Makefile.Common

filter/config.go

@@ -0,0 +1,72 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package filter // import "go.opentelemetry.io/collector/filter"
+
+import (
+	"errors"
+	"regexp"
+)
+
+// Config configures the matching behavior of a FilterSet.
+type Config struct {
+	Strict string `mapstructure:"strict"`
+	Regex  string `mapstructure:"regexp"`
+}
+
+func (c Config) Validate() error {
+	if c.Strict == "" && c.Regex == "" {
+		return errors.New("must specify either strict or regex")
+	}
+	if c.Strict != "" && c.Regex != "" {
+		return errors.New("strict and regex cannot be used together")
+	}
+
+	if c.Regex != "" {
+		_, err := regexp.Compile(c.Regex)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+type CombinedFilter struct {
+	stricts map[any]struct{}
+	regexes []*regexp.Regexp
+}
+
+// CreateFilter creates a Filter from yaml config.
+func CreateFilter(configs []Config) Filter {
+	cf := &CombinedFilter{
+		stricts: make(map[any]struct{}),
+	}
+	for _, config := range configs {
+		if config.Strict != "" {
+			cf.stricts[config.Strict] = struct{}{}
+		}
+
+		if config.Regex != "" {
+			// Validate() call above ensures that the regex is valid.
+			re := regexp.MustCompile(config.Regex)
+			cf.regexes = append(cf.regexes, re)
+		}
+	}
+	return cf
+}
+
+func (cf *CombinedFilter) Matches(toMatch any) bool {
+	_, ok := cf.stricts[toMatch]
+	if ok {
+		return ok
+	}
+	if str, ok := toMatch.(string); ok {
+		for _, re := range cf.regexes {
+			if re.MatchString(str) {
+				return true
+			}
+		}
+	}
+	return false
+}