[chore] Add pipeline module

.chloggen/add-pipeline-module.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: new_component
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: pipeline
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Adds new `pipeline` module to house the concept of pipeline ID and Signal.
+
+# One or more tracking issues or pull requests related to the change
+issues: [11209]
+
+# (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: [api]

Makefile

@@ -303,11 +303,13 @@ check-contrib:
 		-replace go.opentelemetry.io/collector/extension/zpagesextension=$(CURDIR)/extension/zpagesextension  \
 		-replace go.opentelemetry.io/collector/featuregate=$(CURDIR)/featuregate  \
 		-replace go.opentelemetry.io/collector/internal/globalgates=$(CURDIR)/internal/globalgates \
+		-replace go.opentelemetry.io/collector/internal/globalsignal=$(CURDIR)/internal/globalsignal \
 		-replace go.opentelemetry.io/collector/otelcol=$(CURDIR)/otelcol  \
 		-replace go.opentelemetry.io/collector/otelcol/otelcoltest=$(CURDIR)/otelcol/otelcoltest  \
 		-replace go.opentelemetry.io/collector/pdata=$(CURDIR)/pdata  \
 		-replace go.opentelemetry.io/collector/pdata/testdata=$(CURDIR)/pdata/testdata  \
 		-replace go.opentelemetry.io/collector/pdata/pprofile=$(CURDIR)/pdata/pprofile  \
+		-replace go.opentelemetry.io/collector/pipeline=$(CURDIR)/pipeline  \
 		-replace go.opentelemetry.io/collector/processor=$(CURDIR)/processor  \
 		-replace go.opentelemetry.io/collector/processor/batchprocessor=$(CURDIR)/processor/batchprocessor  \
 		-replace go.opentelemetry.io/collector/processor/memorylimiterprocessor=$(CURDIR)/processor/memorylimiterprocessor  \
@@ -369,11 +371,13 @@ restore-contrib:
 		-dropreplace go.opentelemetry.io/collector/extension/zpagesextension  \
 		-dropreplace go.opentelemetry.io/collector/featuregate  \
 		-dropreplace go.opentelemetry.io/collector/internal/globalgates \
+		-dropreplace go.opentelemetry.io/collector/internal/globalsignal \
 		-dropreplace go.opentelemetry.io/collector/otelcol  \
 		-dropreplace go.opentelemetry.io/collector/otelcol/otelcoltest  \
 		-dropreplace go.opentelemetry.io/collector/pdata  \
 		-dropreplace go.opentelemetry.io/collector/pdata/testdata  \
 		-dropreplace go.opentelemetry.io/collector/pdata/pprofile  \
+		-dropreplace go.opentelemetry.io/collector/pipeline  \
 		-dropreplace go.opentelemetry.io/collector/processor  \
 		-dropreplace go.opentelemetry.io/collector/processor/batchprocessor  \
 		-dropreplace go.opentelemetry.io/collector/processor/memorylimiterprocessor  \

internal/globalsignal/Makefile

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

internal/globalsignal/go.mod

@@ -0,0 +1,11 @@
+module go.opentelemetry.io/collector/internal/globalsignal
+
+go 1.22.0
+
+require github.com/stretchr/testify v1.9.0
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

internal/globalsignal/signal.go

@@ -0,0 +1,50 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package globalsignal // import "go.opentelemetry.io/collector/internal/globalsignal"
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// Signal represents the signals supported by the collector.
+type Signal struct {
+	name string
+}
+
+// String returns the string representation of the signal.
+func (s Signal) String() string {
+	return s.name
+}
+
+// MarshalText marshals the Signal.
+func (s Signal) MarshalText() (text []byte, err error) {
+	return []byte(s.name), nil
+}
+
+// signalRegex is used to validate the signal.
+// A signal must consist of 1 to 62 lowercase ASCII alphabetic characters.
+var signalRegex = regexp.MustCompile(`^[a-z]{1,62}$`)
+
+// NewSignal creates a Signal. It returns an error if the Signal is invalid.
+// A Signal must consist of 1 to 62 lowercase ASCII alphabetic characters.
+func NewSignal(signal string) (Signal, error) {
+	if len(signal) == 0 {
+		return Signal{}, fmt.Errorf("signal must not be empty")
+	}
+	if !signalRegex.MatchString(signal) {
+		return Signal{}, fmt.Errorf("invalid character(s) in type %q", signal)
+	}
+	return Signal{name: signal}, nil
+}
+
+// MustNewSignal creates a Signal. It panics if the Signal is invalid.
+// A signal must consist of 1 to 62 lowercase ASCII alphabetic characters.
+func MustNewSignal(signal string) Signal {
+	s, err := NewSignal(signal)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}

internal/globalsignal/signal_test.go

@@ -0,0 +1,41 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package globalsignal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_NewSignal(t *testing.T) {
+	s, err := NewSignal("traces")
+	require.NoError(t, err)
+	assert.Equal(t, Signal{name: "traces"}, s)
+}
+
+func Test_NewSignal_Invalid(t *testing.T) {
+	_, err := NewSignal("")
+	require.Error(t, err)
+	_, err = NewSignal("TRACES")
+	require.Error(t, err)
+}
+
+func Test_MustNewSignal(t *testing.T) {
+	s := MustNewSignal("traces")
+	assert.Equal(t, Signal{name: "traces"}, s)
+}
+
+func Test_Signal_String(t *testing.T) {
+	s := MustNewSignal("traces")
+	assert.Equal(t, "traces", s.String())
+}
+
+func Test_Signal_MarshalText(t *testing.T) {
+	s := MustNewSignal("traces")
+	b, err := s.MarshalText()
+	require.NoError(t, err)
+	assert.Equal(t, []byte("traces"), b)
+}

pipeline/Makefile

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

pipeline/go.mod

@@ -0,0 +1,16 @@
+module go.opentelemetry.io/collector/pipeline
+
+go 1.22.0
+
+require (
+	github.com/stretchr/testify v1.9.0
+	go.opentelemetry.io/collector/internal/globalsignal v0.109.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
+
+replace go.opentelemetry.io/collector/internal/globalsignal => ../internal/globalsignal

pipeline/pipeline.go

@@ -0,0 +1,131 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pipeline // import "go.opentelemetry.io/collector/pipeline"
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"go.opentelemetry.io/collector/internal/globalsignal"
+)
+
+// typeAndNameSeparator is the separator that is used between type and name in type/name composite keys.
+const typeAndNameSeparator = "/"
+
+// ID represents the identity for a pipeline. It combines two values:
+// * signal - the Signal of the pipeline.
+// * name - the name of that pipeline.
+type ID struct {
+	signal Signal `mapstructure:"-"`
+	name   string `mapstructure:"-"`
+}
+
+// NewID returns a new ID with the given Signal and empty name.
+func NewID(signal Signal) ID {
+	return ID{signal: signal}
+}
+
+// MustNewID builds a Signal and returns a new ID with the given Signal and empty name.
+// It panics if the Signal is invalid.
+// A signal must consist of 1 to 62 lowercase ASCII alphabetic characters.
+func MustNewID(signal string) ID {
+	return ID{signal: globalsignal.MustNewSignal(signal)}
+}
+
+// NewIDWithName returns a new ID with the given Signal and name.
+func NewIDWithName(signal Signal, name string) ID {
+	return ID{signal: signal, name: name}
+}
+
+// MustNewIDWithName builds a Signal and returns a new ID with the given Signal and name.
+// It panics if the Signal is invalid or name is invalid.
+// A signal must consist of 1 to 62 lowercase ASCII alphabetic characters.
+// A name must consist of 1 to 1024 unicode characters excluding whitespace, control characters, and symbols.
+func MustNewIDWithName(signal string, name string) ID {
+	id := ID{signal: globalsignal.MustNewSignal(signal)}
+	err := validateName(name)
+	if err != nil {
+		panic(err)
+	}
+	id.name = name
+	return id
+}
+
+// Signal returns the Signal of the ID.
+func (i ID) Signal() Signal {
+	return i.signal
+}
+
+// Name returns the name of the ID.
+func (i ID) Name() string {
+	return i.name
+}
+
+// MarshalText implements the encoding.TextMarshaler interface.
+// This marshals the Signal and name as one string in the config.
+func (i ID) MarshalText() (text []byte, err error) {
+	return []byte(i.String()), nil
+}
+
+// UnmarshalText implements the encoding.TextUnmarshaler interface.
+func (i *ID) UnmarshalText(text []byte) error {
+	idStr := string(text)
+	items := strings.SplitN(idStr, typeAndNameSeparator, 2)
+	var signalStr, nameStr string
+	if len(items) >= 1 {
+		signalStr = strings.TrimSpace(items[0])
+	}
+
+	if len(items) == 1 && signalStr == "" {
+		return errors.New("id must not be empty")
+	}
+
+	if signalStr == "" {
+		return fmt.Errorf("in %q id: the part before %s should not be empty", idStr, typeAndNameSeparator)
+	}
+
+	if len(items) > 1 {
+		// "name" part is present.
+		nameStr = strings.TrimSpace(items[1])
+		if nameStr == "" {
+			return fmt.Errorf("in %q id: the part after %s should not be empty", idStr, typeAndNameSeparator)
+		}
+		if err := validateName(nameStr); err != nil {
+			return fmt.Errorf("in %q id: %w", nameStr, err)
+		}
+	}
+
+	var err error
+	if i.signal, err = globalsignal.NewSignal(signalStr); err != nil {
+		return fmt.Errorf("in %q id: %w", idStr, err)
+	}
+	i.name = nameStr
+
+	return nil
+}
+
+// String returns the ID string representation as "signal[/name]" format.
+func (i ID) String() string {
+	if i.name == "" {
+		return i.signal.String()
+	}
+
+	return i.signal.String() + typeAndNameSeparator + i.name
+}
+
+// nameRegexp is used to validate the name of an ID. A name can consist of
+// 1 to 1024 unicode characters excluding whitespace, control characters, and
+// symbols.
+var nameRegexp = regexp.MustCompile(`^[^\pZ\pC\pS]+$`)
+
+func validateName(nameStr string) error {
+	if len(nameStr) > 1024 {
+		return fmt.Errorf("name %q is longer than 1024 characters (%d characters)", nameStr, len(nameStr))
+	}
+	if !nameRegexp.MatchString(nameStr) {
+		return fmt.Errorf("invalid character(s) in name %q", nameStr)
+	}
+	return nil
+}