feat: Production readiness improvements for WHOOSH council formation

Major security, observability, and configuration improvements:

## Security Hardening
- Implemented configurable CORS (no more wildcards)
- Added comprehensive auth middleware for admin endpoints
- Enhanced webhook HMAC validation
- Added input validation and rate limiting
- Security headers and CSP policies

## Configuration Management
- Made N8N webhook URL configurable (WHOOSH_N8N_BASE_URL)
- Replaced all hardcoded endpoints with environment variables
- Added feature flags for LLM vs heuristic composition
- Gitea fetch hardening with EAGER_FILTER and FULL_RESCAN options

## API Completeness
- Implemented GetCouncilComposition function
- Added GET /api/v1/councils/{id} endpoint
- Council artifacts API (POST/GET /api/v1/councils/{id}/artifacts)
- /admin/health/details endpoint with component status
- Database lookup for repository URLs (no hardcoded fallbacks)

## Observability & Performance
- Added OpenTelemetry distributed tracing with goal/pulse correlation
- Performance optimization database indexes
- Comprehensive health monitoring
- Enhanced logging and error handling

## Infrastructure
- Production-ready P2P discovery (replaces mock implementation)
- Removed unused Redis configuration
- Enhanced Docker Swarm integration
- Added migration files for performance indexes

## Code Quality
- Comprehensive input validation
- Graceful error handling and failsafe fallbacks
- Backwards compatibility maintained
- Following security best practices

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

vendor/go.opentelemetry.io/otel/internal/global/handler.go

@@ -0,0 +1,102 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"log"
+	"os"
+	"sync/atomic"
+)
+
+var (
+	// GlobalErrorHandler provides an ErrorHandler that can be used
+	// throughout an OpenTelemetry instrumented project. When a user
+	// specified ErrorHandler is registered (`SetErrorHandler`) all calls to
+	// `Handle` and will be delegated to the registered ErrorHandler.
+	GlobalErrorHandler = defaultErrorHandler()
+
+	// Compile-time check that delegator implements ErrorHandler.
+	_ ErrorHandler = (*ErrDelegator)(nil)
+	// Compile-time check that errLogger implements ErrorHandler.
+	_ ErrorHandler = (*ErrLogger)(nil)
+)
+
+// ErrorHandler handles irremediable events.
+type ErrorHandler interface {
+	// Handle handles any error deemed irremediable by an OpenTelemetry
+	// component.
+	Handle(error)
+}
+
+type ErrDelegator struct {
+	delegate atomic.Pointer[ErrorHandler]
+}
+
+func (d *ErrDelegator) Handle(err error) {
+	d.getDelegate().Handle(err)
+}
+
+func (d *ErrDelegator) getDelegate() ErrorHandler {
+	return *d.delegate.Load()
+}
+
+// setDelegate sets the ErrorHandler delegate.
+func (d *ErrDelegator) setDelegate(eh ErrorHandler) {
+	d.delegate.Store(&eh)
+}
+
+func defaultErrorHandler() *ErrDelegator {
+	d := &ErrDelegator{}
+	d.setDelegate(&ErrLogger{l: log.New(os.Stderr, "", log.LstdFlags)})
+	return d
+}
+
+// ErrLogger logs errors if no delegate is set, otherwise they are delegated.
+type ErrLogger struct {
+	l *log.Logger
+}
+
+// Handle logs err if no delegate is set, otherwise it is delegated.
+func (h *ErrLogger) Handle(err error) {
+	h.l.Print(err)
+}
+
+// GetErrorHandler returns the global ErrorHandler instance.
+//
+// The default ErrorHandler instance returned will log all errors to STDERR
+// until an override ErrorHandler is set with SetErrorHandler. All
+// ErrorHandler returned prior to this will automatically forward errors to
+// the set instance instead of logging.
+//
+// Subsequent calls to SetErrorHandler after the first will not forward errors
+// to the new ErrorHandler for prior returned instances.
+func GetErrorHandler() ErrorHandler {
+	return GlobalErrorHandler
+}
+
+// SetErrorHandler sets the global ErrorHandler to h.
+//
+// The first time this is called all ErrorHandler previously returned from
+// GetErrorHandler will send errors to h instead of the default logging
+// ErrorHandler. Subsequent calls will set the global ErrorHandler, but not
+// delegate errors to h.
+func SetErrorHandler(h ErrorHandler) {
+	GlobalErrorHandler.setDelegate(h)
+}
+
+// Handle is a convenience function for ErrorHandler().Handle(err).
+func Handle(err error) {
+	GetErrorHandler().Handle(err)
+}

vendor/go.opentelemetry.io/otel/internal/global/instruments.go

@@ -0,0 +1,371 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"context"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/embedded"
+)
+
+// unwrapper unwraps to return the underlying instrument implementation.
+type unwrapper interface {
+	Unwrap() metric.Observable
+}
+
+type afCounter struct {
+	embedded.Float64ObservableCounter
+	metric.Float64Observable
+
+	name string
+	opts []metric.Float64ObservableCounterOption
+
+	delegate atomic.Value // metric.Float64ObservableCounter
+}
+
+var (
+	_ unwrapper                       = (*afCounter)(nil)
+	_ metric.Float64ObservableCounter = (*afCounter)(nil)
+)
+
+func (i *afCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Float64ObservableCounter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *afCounter) Unwrap() metric.Observable {
+	if ctr := i.delegate.Load(); ctr != nil {
+		return ctr.(metric.Float64ObservableCounter)
+	}
+	return nil
+}
+
+type afUpDownCounter struct {
+	embedded.Float64ObservableUpDownCounter
+	metric.Float64Observable
+
+	name string
+	opts []metric.Float64ObservableUpDownCounterOption
+
+	delegate atomic.Value // metric.Float64ObservableUpDownCounter
+}
+
+var (
+	_ unwrapper                             = (*afUpDownCounter)(nil)
+	_ metric.Float64ObservableUpDownCounter = (*afUpDownCounter)(nil)
+)
+
+func (i *afUpDownCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Float64ObservableUpDownCounter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *afUpDownCounter) Unwrap() metric.Observable {
+	if ctr := i.delegate.Load(); ctr != nil {
+		return ctr.(metric.Float64ObservableUpDownCounter)
+	}
+	return nil
+}
+
+type afGauge struct {
+	embedded.Float64ObservableGauge
+	metric.Float64Observable
+
+	name string
+	opts []metric.Float64ObservableGaugeOption
+
+	delegate atomic.Value // metric.Float64ObservableGauge
+}
+
+var (
+	_ unwrapper                     = (*afGauge)(nil)
+	_ metric.Float64ObservableGauge = (*afGauge)(nil)
+)
+
+func (i *afGauge) setDelegate(m metric.Meter) {
+	ctr, err := m.Float64ObservableGauge(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *afGauge) Unwrap() metric.Observable {
+	if ctr := i.delegate.Load(); ctr != nil {
+		return ctr.(metric.Float64ObservableGauge)
+	}
+	return nil
+}
+
+type aiCounter struct {
+	embedded.Int64ObservableCounter
+	metric.Int64Observable
+
+	name string
+	opts []metric.Int64ObservableCounterOption
+
+	delegate atomic.Value // metric.Int64ObservableCounter
+}
+
+var (
+	_ unwrapper                     = (*aiCounter)(nil)
+	_ metric.Int64ObservableCounter = (*aiCounter)(nil)
+)
+
+func (i *aiCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Int64ObservableCounter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *aiCounter) Unwrap() metric.Observable {
+	if ctr := i.delegate.Load(); ctr != nil {
+		return ctr.(metric.Int64ObservableCounter)
+	}
+	return nil
+}
+
+type aiUpDownCounter struct {
+	embedded.Int64ObservableUpDownCounter
+	metric.Int64Observable
+
+	name string
+	opts []metric.Int64ObservableUpDownCounterOption
+
+	delegate atomic.Value // metric.Int64ObservableUpDownCounter
+}
+
+var (
+	_ unwrapper                           = (*aiUpDownCounter)(nil)
+	_ metric.Int64ObservableUpDownCounter = (*aiUpDownCounter)(nil)
+)
+
+func (i *aiUpDownCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Int64ObservableUpDownCounter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *aiUpDownCounter) Unwrap() metric.Observable {
+	if ctr := i.delegate.Load(); ctr != nil {
+		return ctr.(metric.Int64ObservableUpDownCounter)
+	}
+	return nil
+}
+
+type aiGauge struct {
+	embedded.Int64ObservableGauge
+	metric.Int64Observable
+
+	name string
+	opts []metric.Int64ObservableGaugeOption
+
+	delegate atomic.Value // metric.Int64ObservableGauge
+}
+
+var (
+	_ unwrapper                   = (*aiGauge)(nil)
+	_ metric.Int64ObservableGauge = (*aiGauge)(nil)
+)
+
+func (i *aiGauge) setDelegate(m metric.Meter) {
+	ctr, err := m.Int64ObservableGauge(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *aiGauge) Unwrap() metric.Observable {
+	if ctr := i.delegate.Load(); ctr != nil {
+		return ctr.(metric.Int64ObservableGauge)
+	}
+	return nil
+}
+
+// Sync Instruments.
+type sfCounter struct {
+	embedded.Float64Counter
+
+	name string
+	opts []metric.Float64CounterOption
+
+	delegate atomic.Value // metric.Float64Counter
+}
+
+var _ metric.Float64Counter = (*sfCounter)(nil)
+
+func (i *sfCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Float64Counter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *sfCounter) Add(ctx context.Context, incr float64, opts ...metric.AddOption) {
+	if ctr := i.delegate.Load(); ctr != nil {
+		ctr.(metric.Float64Counter).Add(ctx, incr, opts...)
+	}
+}
+
+type sfUpDownCounter struct {
+	embedded.Float64UpDownCounter
+
+	name string
+	opts []metric.Float64UpDownCounterOption
+
+	delegate atomic.Value // metric.Float64UpDownCounter
+}
+
+var _ metric.Float64UpDownCounter = (*sfUpDownCounter)(nil)
+
+func (i *sfUpDownCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Float64UpDownCounter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *sfUpDownCounter) Add(ctx context.Context, incr float64, opts ...metric.AddOption) {
+	if ctr := i.delegate.Load(); ctr != nil {
+		ctr.(metric.Float64UpDownCounter).Add(ctx, incr, opts...)
+	}
+}
+
+type sfHistogram struct {
+	embedded.Float64Histogram
+
+	name string
+	opts []metric.Float64HistogramOption
+
+	delegate atomic.Value // metric.Float64Histogram
+}
+
+var _ metric.Float64Histogram = (*sfHistogram)(nil)
+
+func (i *sfHistogram) setDelegate(m metric.Meter) {
+	ctr, err := m.Float64Histogram(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *sfHistogram) Record(ctx context.Context, x float64, opts ...metric.RecordOption) {
+	if ctr := i.delegate.Load(); ctr != nil {
+		ctr.(metric.Float64Histogram).Record(ctx, x, opts...)
+	}
+}
+
+type siCounter struct {
+	embedded.Int64Counter
+
+	name string
+	opts []metric.Int64CounterOption
+
+	delegate atomic.Value // metric.Int64Counter
+}
+
+var _ metric.Int64Counter = (*siCounter)(nil)
+
+func (i *siCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Int64Counter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *siCounter) Add(ctx context.Context, x int64, opts ...metric.AddOption) {
+	if ctr := i.delegate.Load(); ctr != nil {
+		ctr.(metric.Int64Counter).Add(ctx, x, opts...)
+	}
+}
+
+type siUpDownCounter struct {
+	embedded.Int64UpDownCounter
+
+	name string
+	opts []metric.Int64UpDownCounterOption
+
+	delegate atomic.Value // metric.Int64UpDownCounter
+}
+
+var _ metric.Int64UpDownCounter = (*siUpDownCounter)(nil)
+
+func (i *siUpDownCounter) setDelegate(m metric.Meter) {
+	ctr, err := m.Int64UpDownCounter(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *siUpDownCounter) Add(ctx context.Context, x int64, opts ...metric.AddOption) {
+	if ctr := i.delegate.Load(); ctr != nil {
+		ctr.(metric.Int64UpDownCounter).Add(ctx, x, opts...)
+	}
+}
+
+type siHistogram struct {
+	embedded.Int64Histogram
+
+	name string
+	opts []metric.Int64HistogramOption
+
+	delegate atomic.Value // metric.Int64Histogram
+}
+
+var _ metric.Int64Histogram = (*siHistogram)(nil)
+
+func (i *siHistogram) setDelegate(m metric.Meter) {
+	ctr, err := m.Int64Histogram(i.name, i.opts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+		return
+	}
+	i.delegate.Store(ctr)
+}
+
+func (i *siHistogram) Record(ctx context.Context, x int64, opts ...metric.RecordOption) {
+	if ctr := i.delegate.Load(); ctr != nil {
+		ctr.(metric.Int64Histogram).Record(ctx, x, opts...)
+	}
+}

vendor/go.opentelemetry.io/otel/internal/global/internal_logging.go

@@ -0,0 +1,69 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"log"
+	"os"
+	"sync/atomic"
+
+	"github.com/go-logr/logr"
+	"github.com/go-logr/stdr"
+)
+
+// globalLogger is the logging interface used within the otel api and sdk provide details of the internals.
+//
+// The default logger uses stdr which is backed by the standard `log.Logger`
+// interface. This logger will only show messages at the Error Level.
+var globalLogger atomic.Pointer[logr.Logger]
+
+func init() {
+	SetLogger(stdr.New(log.New(os.Stderr, "", log.LstdFlags|log.Lshortfile)))
+}
+
+// SetLogger overrides the globalLogger with l.
+//
+// To see Warn messages use a logger with `l.V(1).Enabled() == true`
+// To see Info messages use a logger with `l.V(4).Enabled() == true`
+// To see Debug messages use a logger with `l.V(8).Enabled() == true`.
+func SetLogger(l logr.Logger) {
+	globalLogger.Store(&l)
+}
+
+func getLogger() logr.Logger {
+	return *globalLogger.Load()
+}
+
+// Info prints messages about the general state of the API or SDK.
+// This should usually be less than 5 messages a minute.
+func Info(msg string, keysAndValues ...interface{}) {
+	getLogger().V(4).Info(msg, keysAndValues...)
+}
+
+// Error prints messages about exceptional states of the API or SDK.
+func Error(err error, msg string, keysAndValues ...interface{}) {
+	getLogger().Error(err, msg, keysAndValues...)
+}
+
+// Debug prints messages about all internal changes in the API or SDK.
+func Debug(msg string, keysAndValues ...interface{}) {
+	getLogger().V(8).Info(msg, keysAndValues...)
+}
+
+// Warn prints messages about warnings in the API or SDK.
+// Not an error but is likely more important than an informational event.
+func Warn(msg string, keysAndValues ...interface{}) {
+	getLogger().V(1).Info(msg, keysAndValues...)
+}

vendor/go.opentelemetry.io/otel/internal/global/meter.go

@@ -0,0 +1,356 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"container/list"
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/embedded"
+)
+
+// meterProvider is a placeholder for a configured SDK MeterProvider.
+//
+// All MeterProvider functionality is forwarded to a delegate once
+// configured.
+type meterProvider struct {
+	embedded.MeterProvider
+
+	mtx    sync.Mutex
+	meters map[il]*meter
+
+	delegate metric.MeterProvider
+}
+
+// setDelegate configures p to delegate all MeterProvider functionality to
+// provider.
+//
+// All Meters provided prior to this function call are switched out to be
+// Meters provided by provider. All instruments and callbacks are recreated and
+// delegated.
+//
+// It is guaranteed by the caller that this happens only once.
+func (p *meterProvider) setDelegate(provider metric.MeterProvider) {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	p.delegate = provider
+
+	if len(p.meters) == 0 {
+		return
+	}
+
+	for _, meter := range p.meters {
+		meter.setDelegate(provider)
+	}
+
+	p.meters = nil
+}
+
+// Meter implements MeterProvider.
+func (p *meterProvider) Meter(name string, opts ...metric.MeterOption) metric.Meter {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Meter(name, opts...)
+	}
+
+	// At this moment it is guaranteed that no sdk is installed, save the meter in the meters map.
+
+	c := metric.NewMeterConfig(opts...)
+	key := il{
+		name:    name,
+		version: c.InstrumentationVersion(),
+	}
+
+	if p.meters == nil {
+		p.meters = make(map[il]*meter)
+	}
+
+	if val, ok := p.meters[key]; ok {
+		return val
+	}
+
+	t := &meter{name: name, opts: opts}
+	p.meters[key] = t
+	return t
+}
+
+// meter is a placeholder for a metric.Meter.
+//
+// All Meter functionality is forwarded to a delegate once configured.
+// Otherwise, all functionality is forwarded to a NoopMeter.
+type meter struct {
+	embedded.Meter
+
+	name string
+	opts []metric.MeterOption
+
+	mtx         sync.Mutex
+	instruments []delegatedInstrument
+
+	registry list.List
+
+	delegate atomic.Value // metric.Meter
+}
+
+type delegatedInstrument interface {
+	setDelegate(metric.Meter)
+}
+
+// setDelegate configures m to delegate all Meter functionality to Meters
+// created by provider.
+//
+// All subsequent calls to the Meter methods will be passed to the delegate.
+//
+// It is guaranteed by the caller that this happens only once.
+func (m *meter) setDelegate(provider metric.MeterProvider) {
+	meter := provider.Meter(m.name, m.opts...)
+	m.delegate.Store(meter)
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	for _, inst := range m.instruments {
+		inst.setDelegate(meter)
+	}
+
+	var n *list.Element
+	for e := m.registry.Front(); e != nil; e = n {
+		r := e.Value.(*registration)
+		r.setDelegate(meter)
+		n = e.Next()
+		m.registry.Remove(e)
+	}
+
+	m.instruments = nil
+	m.registry.Init()
+}
+
+func (m *meter) Int64Counter(name string, options ...metric.Int64CounterOption) (metric.Int64Counter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Int64Counter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &siCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Int64UpDownCounter(name string, options ...metric.Int64UpDownCounterOption) (metric.Int64UpDownCounter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Int64UpDownCounter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &siUpDownCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Int64Histogram(name string, options ...metric.Int64HistogramOption) (metric.Int64Histogram, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Int64Histogram(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &siHistogram{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Int64ObservableCounter(name string, options ...metric.Int64ObservableCounterOption) (metric.Int64ObservableCounter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Int64ObservableCounter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &aiCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Int64ObservableUpDownCounter(name string, options ...metric.Int64ObservableUpDownCounterOption) (metric.Int64ObservableUpDownCounter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Int64ObservableUpDownCounter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &aiUpDownCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Int64ObservableGauge(name string, options ...metric.Int64ObservableGaugeOption) (metric.Int64ObservableGauge, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Int64ObservableGauge(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &aiGauge{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Float64Counter(name string, options ...metric.Float64CounterOption) (metric.Float64Counter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Float64Counter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &sfCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Float64UpDownCounter(name string, options ...metric.Float64UpDownCounterOption) (metric.Float64UpDownCounter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Float64UpDownCounter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &sfUpDownCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Float64Histogram(name string, options ...metric.Float64HistogramOption) (metric.Float64Histogram, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Float64Histogram(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &sfHistogram{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Float64ObservableCounter(name string, options ...metric.Float64ObservableCounterOption) (metric.Float64ObservableCounter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Float64ObservableCounter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &afCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Float64ObservableUpDownCounter(name string, options ...metric.Float64ObservableUpDownCounterOption) (metric.Float64ObservableUpDownCounter, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Float64ObservableUpDownCounter(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &afUpDownCounter{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+func (m *meter) Float64ObservableGauge(name string, options ...metric.Float64ObservableGaugeOption) (metric.Float64ObservableGauge, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		return del.Float64ObservableGauge(name, options...)
+	}
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	i := &afGauge{name: name, opts: options}
+	m.instruments = append(m.instruments, i)
+	return i, nil
+}
+
+// RegisterCallback captures the function that will be called during Collect.
+func (m *meter) RegisterCallback(f metric.Callback, insts ...metric.Observable) (metric.Registration, error) {
+	if del, ok := m.delegate.Load().(metric.Meter); ok {
+		insts = unwrapInstruments(insts)
+		return del.RegisterCallback(f, insts...)
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	reg := &registration{instruments: insts, function: f}
+	e := m.registry.PushBack(reg)
+	reg.unreg = func() error {
+		m.mtx.Lock()
+		_ = m.registry.Remove(e)
+		m.mtx.Unlock()
+		return nil
+	}
+	return reg, nil
+}
+
+type wrapped interface {
+	unwrap() metric.Observable
+}
+
+func unwrapInstruments(instruments []metric.Observable) []metric.Observable {
+	out := make([]metric.Observable, 0, len(instruments))
+
+	for _, inst := range instruments {
+		if in, ok := inst.(wrapped); ok {
+			out = append(out, in.unwrap())
+		} else {
+			out = append(out, inst)
+		}
+	}
+
+	return out
+}
+
+type registration struct {
+	embedded.Registration
+
+	instruments []metric.Observable
+	function    metric.Callback
+
+	unreg   func() error
+	unregMu sync.Mutex
+}
+
+func (c *registration) setDelegate(m metric.Meter) {
+	insts := unwrapInstruments(c.instruments)
+
+	c.unregMu.Lock()
+	defer c.unregMu.Unlock()
+
+	if c.unreg == nil {
+		// Unregister already called.
+		return
+	}
+
+	reg, err := m.RegisterCallback(c.function, insts...)
+	if err != nil {
+		GetErrorHandler().Handle(err)
+	}
+
+	c.unreg = reg.Unregister
+}
+
+func (c *registration) Unregister() error {
+	c.unregMu.Lock()
+	defer c.unregMu.Unlock()
+	if c.unreg == nil {
+		// Unregister already called.
+		return nil
+	}
+
+	var err error
+	err, c.unreg = c.unreg(), nil
+	return err
+}

vendor/go.opentelemetry.io/otel/internal/global/propagator.go

@@ -0,0 +1,82 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/propagation"
+)
+
+// textMapPropagator is a default TextMapPropagator that delegates calls to a
+// registered delegate if one is set, otherwise it defaults to delegating the
+// calls to a the default no-op propagation.TextMapPropagator.
+type textMapPropagator struct {
+	mtx      sync.Mutex
+	once     sync.Once
+	delegate propagation.TextMapPropagator
+	noop     propagation.TextMapPropagator
+}
+
+// Compile-time guarantee that textMapPropagator implements the
+// propagation.TextMapPropagator interface.
+var _ propagation.TextMapPropagator = (*textMapPropagator)(nil)
+
+func newTextMapPropagator() *textMapPropagator {
+	return &textMapPropagator{
+		noop: propagation.NewCompositeTextMapPropagator(),
+	}
+}
+
+// SetDelegate sets a delegate propagation.TextMapPropagator that all calls are
+// forwarded to. Delegation can only be performed once, all subsequent calls
+// perform no delegation.
+func (p *textMapPropagator) SetDelegate(delegate propagation.TextMapPropagator) {
+	if delegate == nil {
+		return
+	}
+
+	p.mtx.Lock()
+	p.once.Do(func() { p.delegate = delegate })
+	p.mtx.Unlock()
+}
+
+// effectiveDelegate returns the current delegate of p if one is set,
+// otherwise the default noop TextMapPropagator is returned. This method
+// can be called concurrently.
+func (p *textMapPropagator) effectiveDelegate() propagation.TextMapPropagator {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+	if p.delegate != nil {
+		return p.delegate
+	}
+	return p.noop
+}
+
+// Inject set cross-cutting concerns from the Context into the carrier.
+func (p *textMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
+	p.effectiveDelegate().Inject(ctx, carrier)
+}
+
+// Extract reads cross-cutting concerns from the carrier into a Context.
+func (p *textMapPropagator) Extract(ctx context.Context, carrier propagation.TextMapCarrier) context.Context {
+	return p.effectiveDelegate().Extract(ctx, carrier)
+}
+
+// Fields returns the keys whose values are set with Inject.
+func (p *textMapPropagator) Fields() []string {
+	return p.effectiveDelegate().Fields()
+}

vendor/go.opentelemetry.io/otel/internal/global/state.go

@@ -0,0 +1,156 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+import (
+	"errors"
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/trace"
+)
+
+type (
+	tracerProviderHolder struct {
+		tp trace.TracerProvider
+	}
+
+	propagatorsHolder struct {
+		tm propagation.TextMapPropagator
+	}
+
+	meterProviderHolder struct {
+		mp metric.MeterProvider
+	}
+)
+
+var (
+	globalTracer        = defaultTracerValue()
+	globalPropagators   = defaultPropagatorsValue()
+	globalMeterProvider = defaultMeterProvider()
+
+	delegateTraceOnce             sync.Once
+	delegateTextMapPropagatorOnce sync.Once
+	delegateMeterOnce             sync.Once
+)
+
+// TracerProvider is the internal implementation for global.TracerProvider.
+func TracerProvider() trace.TracerProvider {
+	return globalTracer.Load().(tracerProviderHolder).tp
+}
+
+// SetTracerProvider is the internal implementation for global.SetTracerProvider.
+func SetTracerProvider(tp trace.TracerProvider) {
+	current := TracerProvider()
+
+	if _, cOk := current.(*tracerProvider); cOk {
+		if _, tpOk := tp.(*tracerProvider); tpOk && current == tp {
+			// Do not assign the default delegating TracerProvider to delegate
+			// to itself.
+			Error(
+				errors.New("no delegate configured in tracer provider"),
+				"Setting tracer provider to its current value. No delegate will be configured",
+			)
+			return
+		}
+	}
+
+	delegateTraceOnce.Do(func() {
+		if def, ok := current.(*tracerProvider); ok {
+			def.setDelegate(tp)
+		}
+	})
+	globalTracer.Store(tracerProviderHolder{tp: tp})
+}
+
+// TextMapPropagator is the internal implementation for global.TextMapPropagator.
+func TextMapPropagator() propagation.TextMapPropagator {
+	return globalPropagators.Load().(propagatorsHolder).tm
+}
+
+// SetTextMapPropagator is the internal implementation for global.SetTextMapPropagator.
+func SetTextMapPropagator(p propagation.TextMapPropagator) {
+	current := TextMapPropagator()
+
+	if _, cOk := current.(*textMapPropagator); cOk {
+		if _, pOk := p.(*textMapPropagator); pOk && current == p {
+			// Do not assign the default delegating TextMapPropagator to
+			// delegate to itself.
+			Error(
+				errors.New("no delegate configured in text map propagator"),
+				"Setting text map propagator to its current value. No delegate will be configured",
+			)
+			return
+		}
+	}
+
+	// For the textMapPropagator already returned by TextMapPropagator
+	// delegate to p.
+	delegateTextMapPropagatorOnce.Do(func() {
+		if def, ok := current.(*textMapPropagator); ok {
+			def.SetDelegate(p)
+		}
+	})
+	// Return p when subsequent calls to TextMapPropagator are made.
+	globalPropagators.Store(propagatorsHolder{tm: p})
+}
+
+// MeterProvider is the internal implementation for global.MeterProvider.
+func MeterProvider() metric.MeterProvider {
+	return globalMeterProvider.Load().(meterProviderHolder).mp
+}
+
+// SetMeterProvider is the internal implementation for global.SetMeterProvider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	current := MeterProvider()
+	if _, cOk := current.(*meterProvider); cOk {
+		if _, mpOk := mp.(*meterProvider); mpOk && current == mp {
+			// Do not assign the default delegating MeterProvider to delegate
+			// to itself.
+			Error(
+				errors.New("no delegate configured in meter provider"),
+				"Setting meter provider to its current value. No delegate will be configured",
+			)
+			return
+		}
+	}
+
+	delegateMeterOnce.Do(func() {
+		if def, ok := current.(*meterProvider); ok {
+			def.setDelegate(mp)
+		}
+	})
+	globalMeterProvider.Store(meterProviderHolder{mp: mp})
+}
+
+func defaultTracerValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(tracerProviderHolder{tp: &tracerProvider{}})
+	return v
+}
+
+func defaultPropagatorsValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(propagatorsHolder{tm: newTextMapPropagator()})
+	return v
+}
+
+func defaultMeterProvider() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(meterProviderHolder{mp: &meterProvider{}})
+	return v
+}

vendor/go.opentelemetry.io/otel/internal/global/trace.go

@@ -0,0 +1,199 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/internal/global"
+
+/*
+This file contains the forwarding implementation of the TracerProvider used as
+the default global instance. Prior to initialization of an SDK, Tracers
+returned by the global TracerProvider will provide no-op functionality. This
+means that all Span created prior to initialization are no-op Spans.
+
+Once an SDK has been initialized, all provided no-op Tracers are swapped for
+Tracers provided by the SDK defined TracerProvider. However, any Span started
+prior to this initialization does not change its behavior. Meaning, the Span
+remains a no-op Span.
+
+The implementation to track and swap Tracers locks all new Tracer creation
+until the swap is complete. This assumes that this operation is not
+performance-critical. If that assumption is incorrect, be sure to configure an
+SDK prior to any Tracer creation.
+*/
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+	"go.opentelemetry.io/otel/trace/embedded"
+)
+
+// tracerProvider is a placeholder for a configured SDK TracerProvider.
+//
+// All TracerProvider functionality is forwarded to a delegate once
+// configured.
+type tracerProvider struct {
+	embedded.TracerProvider
+
+	mtx      sync.Mutex
+	tracers  map[il]*tracer
+	delegate trace.TracerProvider
+}
+
+// Compile-time guarantee that tracerProvider implements the TracerProvider
+// interface.
+var _ trace.TracerProvider = &tracerProvider{}
+
+// setDelegate configures p to delegate all TracerProvider functionality to
+// provider.
+//
+// All Tracers provided prior to this function call are switched out to be
+// Tracers provided by provider.
+//
+// It is guaranteed by the caller that this happens only once.
+func (p *tracerProvider) setDelegate(provider trace.TracerProvider) {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	p.delegate = provider
+
+	if len(p.tracers) == 0 {
+		return
+	}
+
+	for _, t := range p.tracers {
+		t.setDelegate(provider)
+	}
+
+	p.tracers = nil
+}
+
+// Tracer implements TracerProvider.
+func (p *tracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.Tracer {
+	p.mtx.Lock()
+	defer p.mtx.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Tracer(name, opts...)
+	}
+
+	// At this moment it is guaranteed that no sdk is installed, save the tracer in the tracers map.
+
+	c := trace.NewTracerConfig(opts...)
+	key := il{
+		name:    name,
+		version: c.InstrumentationVersion(),
+	}
+
+	if p.tracers == nil {
+		p.tracers = make(map[il]*tracer)
+	}
+
+	if val, ok := p.tracers[key]; ok {
+		return val
+	}
+
+	t := &tracer{name: name, opts: opts, provider: p}
+	p.tracers[key] = t
+	return t
+}
+
+type il struct {
+	name    string
+	version string
+}
+
+// tracer is a placeholder for a trace.Tracer.
+//
+// All Tracer functionality is forwarded to a delegate once configured.
+// Otherwise, all functionality is forwarded to a NoopTracer.
+type tracer struct {
+	embedded.Tracer
+
+	name     string
+	opts     []trace.TracerOption
+	provider *tracerProvider
+
+	delegate atomic.Value
+}
+
+// Compile-time guarantee that tracer implements the trace.Tracer interface.
+var _ trace.Tracer = &tracer{}
+
+// setDelegate configures t to delegate all Tracer functionality to Tracers
+// created by provider.
+//
+// All subsequent calls to the Tracer methods will be passed to the delegate.
+//
+// It is guaranteed by the caller that this happens only once.
+func (t *tracer) setDelegate(provider trace.TracerProvider) {
+	t.delegate.Store(provider.Tracer(t.name, t.opts...))
+}
+
+// Start implements trace.Tracer by forwarding the call to t.delegate if
+// set, otherwise it forwards the call to a NoopTracer.
+func (t *tracer) Start(ctx context.Context, name string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {
+	delegate := t.delegate.Load()
+	if delegate != nil {
+		return delegate.(trace.Tracer).Start(ctx, name, opts...)
+	}
+
+	s := nonRecordingSpan{sc: trace.SpanContextFromContext(ctx), tracer: t}
+	ctx = trace.ContextWithSpan(ctx, s)
+	return ctx, s
+}
+
+// nonRecordingSpan is a minimal implementation of a Span that wraps a
+// SpanContext. It performs no operations other than to return the wrapped
+// SpanContext.
+type nonRecordingSpan struct {
+	embedded.Span
+
+	sc     trace.SpanContext
+	tracer *tracer
+}
+
+var _ trace.Span = nonRecordingSpan{}
+
+// SpanContext returns the wrapped SpanContext.
+func (s nonRecordingSpan) SpanContext() trace.SpanContext { return s.sc }
+
+// IsRecording always returns false.
+func (nonRecordingSpan) IsRecording() bool { return false }
+
+// SetStatus does nothing.
+func (nonRecordingSpan) SetStatus(codes.Code, string) {}
+
+// SetError does nothing.
+func (nonRecordingSpan) SetError(bool) {}
+
+// SetAttributes does nothing.
+func (nonRecordingSpan) SetAttributes(...attribute.KeyValue) {}
+
+// End does nothing.
+func (nonRecordingSpan) End(...trace.SpanEndOption) {}
+
+// RecordError does nothing.
+func (nonRecordingSpan) RecordError(error, ...trace.EventOption) {}
+
+// AddEvent does nothing.
+func (nonRecordingSpan) AddEvent(string, ...trace.EventOption) {}
+
+// SetName does nothing.
+func (nonRecordingSpan) SetName(string) {}
+
+func (s nonRecordingSpan) TracerProvider() trace.TracerProvider { return s.tracer.provider }