Plugins: Add /meta and /metas APIs to plugins app (#113775)

* add /meta and /metas APIs * wrapped storage route * format file * fix switch statement lint issue * fix plugininstaller test --------- Co-authored-by: Todd Treece <todd.treece@grafana.com>
2025-11-24 18:20:11 +00:00
parent 335111e783
commit f1dbbcbe00
33 changed files with 4057 additions and 1041 deletions
@@ -0,0 +1,131 @@
+package meta
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sync"
+	"time"
+
+	pluginsv0alpha1 "github.com/grafana/grafana/apps/plugins/pkg/apis/plugins/v0alpha1"
+)
+
+const (
+	defaultCleanupInterval = 10 * time.Minute
+)
+
+// cachedMeta represents a cached metadata entry with expiration time
+type cachedMeta struct {
+	meta      pluginsv0alpha1.PluginMetaJSONData
+	ttl       time.Duration
+	expiresAt time.Time
+}
+
+// ProviderManager searches multiple providers for Plugin Meta in order until one succeeds, and caches
+// results with per-provider TTLs.
+// It implements app.Runnable to manage the cleanup goroutine lifecycle.
+type ProviderManager struct {
+	providers []Provider
+	cache     map[string]*cachedMeta
+	cacheMu   sync.RWMutex
+}
+
+// NewProviderManager creates a new ProviderManager that chains the given providers
+// and caches results with per-provider TTLs.
+func NewProviderManager(providers ...Provider) *ProviderManager {
+	if len(providers) == 0 {
+		panic("ProviderManager requires at least one provider")
+	}
+
+	return &ProviderManager{
+		providers: providers,
+		cache:     make(map[string]*cachedMeta),
+	}
+}
+
+// Run implements app.Runnable. It runs the cleanup loop until the context is cancelled.
+// This method blocks until the context is cancelled (when the app shuts down).
+func (pm *ProviderManager) Run(ctx context.Context) error {
+	ticker := time.NewTicker(defaultCleanupInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		case <-ticker.C:
+			pm.cleanupExpired()
+		}
+	}
+}
+
+// GetMeta tries each provider in order until one succeeds, using cache when available.
+// Returns ErrMetaNotFound only if all providers return ErrMetaNotFound.
+// Otherwise, returns the last non-ErrMetaNotFound error if all providers fail.
+func (pm *ProviderManager) GetMeta(ctx context.Context, pluginID, version string) (*Result, error) {
+	cacheKey := pm.cacheKey(pluginID, version)
+
+	// Check cache first
+	pm.cacheMu.RLock()
+	cached, exists := pm.cache[cacheKey]
+	pm.cacheMu.RUnlock()
+
+	if exists && time.Now().Before(cached.expiresAt) {
+		return &Result{
+			Meta: cached.meta,
+			TTL:  cached.ttl,
+		}, nil
+	}
+
+	// Try each provider in order until one succeeds
+	var lastErr error
+	for _, provider := range pm.providers {
+		result, err := provider.GetMeta(ctx, pluginID, version)
+		if err == nil {
+			// Don't cache results with a zero TTL
+			if result.TTL == 0 {
+				continue
+			}
+
+			pm.cacheMu.Lock()
+			pm.cache[cacheKey] = &cachedMeta{
+				meta:      result.Meta,
+				ttl:       result.TTL,
+				expiresAt: time.Now().Add(result.TTL),
+			}
+			pm.cacheMu.Unlock()
+
+			return result, nil
+		}
+
+		// If not found, try next provider
+		if errors.Is(err, ErrMetaNotFound) {
+			continue
+		}
+
+		lastErr = err
+	}
+
+	if lastErr != nil {
+		return nil, fmt.Errorf("failed to fetch plugin metadata from any provider: %w", lastErr)
+	}
+
+	return nil, ErrMetaNotFound
+}
+
+// cleanupExpired removes expired entries from the cache.
+func (pm *ProviderManager) cleanupExpired() {
+	now := time.Now()
+
+	pm.cacheMu.Lock()
+	defer pm.cacheMu.Unlock()
+	for key, entry := range pm.cache {
+		if now.After(entry.expiresAt) {
+			delete(pm.cache, key)
+		}
+	}
+}
+
+func (pm *ProviderManager) cacheKey(pluginID, version string) string {
+	return fmt.Sprintf("%s:%s", pluginID, version)
+}