otelconf: add support for v0.4.0

Makefile

@@ -323,7 +323,7 @@ update-all-otel-deps:
 OPENTELEMETRY_CONFIGURATION_JSONSCHEMA_SRC_DIR=tmp/opentelemetry-configuration
 
 # The SHA matching the current version of the opentelemetry-configuration schema to use
-OPENTELEMETRY_CONFIGURATION_JSONSCHEMA_VERSION=v0.3.0
+OPENTELEMETRY_CONFIGURATION_JSONSCHEMA_VERSION=v0.4.0
 
 # Cleanup temporary directory
 genjsonschema-cleanup:

otelconf/v0.4.0/config.go

@@ -0,0 +1,207 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package otelconf provides an OpenTelemetry declarative configuration SDK.
+package otelconf // import "go.opentelemetry.io/contrib/otelconf/v0.3.0"
+
+import (
+	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"os"
+
+	yaml "sigs.k8s.io/yaml/goyaml.v3"
+
+	"go.opentelemetry.io/otel/baggage"
+	"go.opentelemetry.io/otel/log"
+	nooplog "go.opentelemetry.io/otel/log/noop"
+	"go.opentelemetry.io/otel/metric"
+	noopmetric "go.opentelemetry.io/otel/metric/noop"
+	"go.opentelemetry.io/otel/trace"
+	nooptrace "go.opentelemetry.io/otel/trace/noop"
+)
+
+const (
+	compressionGzip = "gzip"
+	compressionNone = "none"
+)
+
+type configOptions struct {
+	ctx                 context.Context
+	opentelemetryConfig OpenTelemetryConfiguration
+}
+
+type shutdownFunc func(context.Context) error
+
+func noopShutdown(context.Context) error {
+	return nil
+}
+
+// SDK is a struct that contains all the providers
+// configured via the configuration model.
+type SDK struct {
+	meterProvider  metric.MeterProvider
+	tracerProvider trace.TracerProvider
+	loggerProvider log.LoggerProvider
+	shutdown       shutdownFunc
+}
+
+// TracerProvider returns a configured trace.TracerProvider.
+func (s *SDK) TracerProvider() trace.TracerProvider {
+	return s.tracerProvider
+}
+
+// MeterProvider returns a configured metric.MeterProvider.
+func (s *SDK) MeterProvider() metric.MeterProvider {
+	return s.meterProvider
+}
+
+// LoggerProvider returns a configured log.LoggerProvider.
+func (s *SDK) LoggerProvider() log.LoggerProvider {
+	return s.loggerProvider
+}
+
+// Shutdown calls shutdown on all configured providers.
+func (s *SDK) Shutdown(ctx context.Context) error {
+	return s.shutdown(ctx)
+}
+
+var noopSDK = SDK{
+	loggerProvider: nooplog.LoggerProvider{},
+	meterProvider:  noopmetric.MeterProvider{},
+	tracerProvider: nooptrace.TracerProvider{},
+	shutdown:       func(ctx context.Context) error { return nil },
+}
+
+// NewSDK creates SDK providers based on the configuration model.
+func NewSDK(opts ...ConfigurationOption) (SDK, error) {
+	o := configOptions{}
+	for _, opt := range opts {
+		o = opt.apply(o)
+	}
+	if o.opentelemetryConfig.Disabled != nil && *o.opentelemetryConfig.Disabled {
+		return noopSDK, nil
+	}
+
+	resource, ok := o.opentelemetryConfig.Resource.(ResourceJson)
+	if !ok {
+		return noopSDK, errors.New("invalid resource")
+	}
+	r := newResource(&resource)
+
+	mp, mpShutdown, err := meterProvider(o, r)
+	if err != nil {
+		return noopSDK, err
+	}
+
+	tp, tpShutdown, err := tracerProvider(o, r)
+	if err != nil {
+		return noopSDK, err
+	}
+
+	lp, lpShutdown, err := loggerProvider(o, r)
+	if err != nil {
+		return noopSDK, err
+	}
+
+	return SDK{
+		meterProvider:  mp,
+		tracerProvider: tp,
+		loggerProvider: lp,
+		shutdown: func(ctx context.Context) error {
+			return errors.Join(mpShutdown(ctx), tpShutdown(ctx), lpShutdown(ctx))
+		},
+	}, nil
+}
+
+// ConfigurationOption configures options for providers.
+type ConfigurationOption interface {
+	apply(configOptions) configOptions
+}
+
+type configurationOptionFunc func(configOptions) configOptions
+
+func (fn configurationOptionFunc) apply(cfg configOptions) configOptions {
+	return fn(cfg)
+}
+
+// WithContext sets the context.Context for the SDK.
+func WithContext(ctx context.Context) ConfigurationOption {
+	return configurationOptionFunc(func(c configOptions) configOptions {
+		c.ctx = ctx
+		return c
+	})
+}
+
+// WithOpenTelemetryConfiguration sets the OpenTelemetryConfiguration used
+// to produce the SDK.
+func WithOpenTelemetryConfiguration(cfg OpenTelemetryConfiguration) ConfigurationOption {
+	return configurationOptionFunc(func(c configOptions) configOptions {
+		c.opentelemetryConfig = cfg
+		return c
+	})
+}
+
+// ParseYAML parses a YAML configuration file into an OpenTelemetryConfiguration.
+func ParseYAML(file []byte) (*OpenTelemetryConfiguration, error) {
+	var cfg OpenTelemetryConfiguration
+	err := yaml.Unmarshal(file, &cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return &cfg, nil
+}
+
+// createTLSConfig creates a tls.Config from certificate files.
+func createTLSConfig(caCertFile *string, clientCertFile *string, clientKeyFile *string) (*tls.Config, error) {
+	tlsConfig := &tls.Config{}
+	if caCertFile != nil {
+		caText, err := os.ReadFile(*caCertFile)
+		if err != nil {
+			return nil, err
+		}
+		certPool := x509.NewCertPool()
+		if !certPool.AppendCertsFromPEM(caText) {
+			return nil, errors.New("could not create certificate authority chain from certificate")
+		}
+		tlsConfig.RootCAs = certPool
+	}
+	if clientCertFile != nil {
+		if clientKeyFile == nil {
+			return nil, errors.New("client certificate was provided but no client key was provided")
+		}
+		clientCert, err := tls.LoadX509KeyPair(*clientCertFile, *clientKeyFile)
+		if err != nil {
+			return nil, fmt.Errorf("could not use client certificate: %w", err)
+		}
+		tlsConfig.Certificates = []tls.Certificate{clientCert}
+	}
+	return tlsConfig, nil
+}
+
+// createHeadersConfig combines the two header config fields. Headers take precedence over headersList.
+func createHeadersConfig(headers []NameStringValuePair, headersList *string) (map[string]string, error) {
+	result := make(map[string]string)
+	if headersList != nil {
+		// Parsing follows https://github.com/open-telemetry/opentelemetry-configuration/blob/568e5080816d40d75792eb754fc96bde09654159/schema/type_descriptions.yaml#L584.
+		headerslist, err := baggage.Parse(*headersList)
+		if err != nil {
+			return nil, fmt.Errorf("invalid headers list: %w", err)
+		}
+		for _, kv := range headerslist.Members() {
+			result[kv.Key()] = kv.Value()
+		}
+	}
+	// Headers take precedence over HeadersList, so this has to be after HeadersList is processed
+	if len(headers) > 0 {
+		for _, kv := range headers {
+			if kv.Value != nil {
+				result[kv.Name] = *kv.Value
+			}
+		}
+	}
+	return result, nil
+}