Security: Add "header" package for setting common response headers #98

Signed-off-by: Michael Mayer <michael@photoprism.app>

internal/server/extensions.go

@@ -0,0 +1,58 @@
+package server
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/photoprism/photoprism/internal/config"
+	"github.com/photoprism/photoprism/pkg/clean"
+)
+
+var (
+	extInit    sync.Once
+	extMutex   sync.Mutex
+	extensions atomic.Value
+)
+
+// Register registers a new package extension.
+func Register(name string, init func(router *gin.Engine, conf *config.Config) error) {
+	extMutex.Lock()
+	h, _ := extensions.Load().(Extensions)
+	extensions.Store(append(h, Extension{name: name, init: init}))
+	extMutex.Unlock()
+}
+
+// Ext returns all registered package extensions.
+func Ext() (ext Extensions) {
+	extMutex.Lock()
+	ext, _ = extensions.Load().(Extensions)
+	extMutex.Unlock()
+	return ext
+}
+
+// Extension represents a named package extension with callbacks.
+type Extension struct {
+	name string
+	init func(router *gin.Engine, conf *config.Config) error
+}
+
+// Extensions represents a list of package extensions.
+type Extensions []Extension
+
+// Init initializes the registered extensions.
+func (ext Extensions) Init(router *gin.Engine, conf *config.Config) {
+	extInit.Do(func() {
+		for _, e := range ext {
+			start := time.Now()
+
+			if err := e.init(router, conf); err != nil {
+				log.Warnf("server: %s in %s extension [%s]", err, clean.Log(e.name), time.Since(start))
+			} else {
+				log.Infof("server: %s extension loaded [%s]", clean.Log(e.name), time.Since(start))
+			}
+		}
+	})
+}