[management, proxy] Add CrowdSec IP reputation integration for reverse proxy (#5722)

proxy/internal/crowdsec/registry.go

@@ -0,0 +1,103 @@
+package crowdsec
+
+import (
+	"context"
+	"sync"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/proxy/internal/types"
+)
+
+// Registry manages a single shared Bouncer instance with reference counting.
+// The bouncer starts when the first service acquires it and stops when the
+// last service releases it.
+type Registry struct {
+	mu      sync.Mutex
+	bouncer *Bouncer
+	refs    map[types.ServiceID]struct{}
+	apiURL  string
+	apiKey  string
+	logger  *log.Entry
+	cancel  context.CancelFunc
+}
+
+// NewRegistry creates a registry. The bouncer is not started until Acquire is called.
+func NewRegistry(apiURL, apiKey string, logger *log.Entry) *Registry {
+	return &Registry{
+		apiURL: apiURL,
+		apiKey: apiKey,
+		logger: logger,
+		refs:   make(map[types.ServiceID]struct{}),
+	}
+}
+
+// Available returns true when the LAPI URL and API key are configured.
+func (r *Registry) Available() bool {
+	return r.apiURL != "" && r.apiKey != ""
+}
+
+// Acquire registers svcID as a consumer and starts the bouncer if this is the
+// first consumer. Returns the shared Bouncer (which implements the restrict
+// package's CrowdSecChecker interface). Returns nil if not Available.
+func (r *Registry) Acquire(svcID types.ServiceID) *Bouncer {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if !r.Available() {
+		return nil
+	}
+
+	if _, exists := r.refs[svcID]; exists {
+		return r.bouncer
+	}
+
+	if r.bouncer == nil {
+		r.startLocked()
+	}
+
+	// startLocked may fail, leaving r.bouncer nil.
+	if r.bouncer == nil {
+		return nil
+	}
+
+	r.refs[svcID] = struct{}{}
+	return r.bouncer
+}
+
+// Release removes svcID as a consumer. Stops the bouncer when the last
+// consumer releases.
+func (r *Registry) Release(svcID types.ServiceID) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	delete(r.refs, svcID)
+
+	if len(r.refs) == 0 && r.bouncer != nil {
+		r.stopLocked()
+	}
+}
+
+func (r *Registry) startLocked() {
+	b := NewBouncer(r.apiURL, r.apiKey, r.logger)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	r.cancel = cancel
+
+	if err := b.Start(ctx); err != nil {
+		r.logger.Errorf("failed to start CrowdSec bouncer: %v", err)
+		cancel()
+		return
+	}
+
+	r.bouncer = b
+	r.logger.Info("CrowdSec bouncer started")
+}
+
+func (r *Registry) stopLocked() {
+	r.bouncer.Stop()
+	r.cancel()
+	r.bouncer = nil
+	r.cancel = nil
+	r.logger.Info("CrowdSec bouncer stopped")
+}