API: Add GET /api/v1/cluster/metrics endpoint #98 #5230

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

internal/api/cluster_metrics.go

@@ -0,0 +1,60 @@
+package api
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/photoprism/photoprism/internal/auth/acl"
+	"github.com/photoprism/photoprism/internal/photoprism/get"
+	"github.com/photoprism/photoprism/internal/service/cluster"
+	reg "github.com/photoprism/photoprism/internal/service/cluster/registry"
+)
+
+// ClusterMetrics returns lightweight metrics about the cluster.
+//
+//	@Summary	temporary cluster metrics (counts only)
+//	@Id		ClusterMetrics
+//	@Tags		Cluster
+//	@Produce	json
+//	@Success	200			{object}	cluster.MetricsResponse
+//	@Failure	401,403,429	{object}	i18n.Response
+//	@Router	/api/v1/cluster/metrics [get]
+func ClusterMetrics(router *gin.RouterGroup) {
+	router.GET("/cluster/metrics", func(c *gin.Context) {
+		s := Auth(c, acl.ResourceCluster, acl.ActionView)
+		if s.Abort(c) {
+			return
+		}
+
+		conf := get.Config()
+		if !conf.IsPortal() {
+			AbortFeatureDisabled(c)
+			return
+		}
+
+		regy, err := reg.NewClientRegistryWithConfig(conf)
+		if err != nil {
+			AbortUnexpectedError(c)
+			return
+		}
+
+		nodes, _ := regy.List()
+		counts := map[string]int{"total": len(nodes)}
+		for _, node := range nodes {
+			role := node.Role
+			if role == "" {
+				role = "unknown"
+			}
+			counts[role]++
+		}
+
+		c.JSON(http.StatusOK, cluster.MetricsResponse{
+			UUID:        conf.ClusterUUID(),
+			ClusterCIDR: conf.ClusterCIDR(),
+			Nodes:       counts,
+			Time:        time.Now().UTC().Format(time.RFC3339),
+		})
+	})
+}