Return proper HTTP status on leave

cluster/cluster.go

@@ -186,6 +186,7 @@ type cluster struct {
 }
 
 var ErrDegraded = errors.New("cluster is currently degraded")
+var ErrUnknownNode = errors.New("unknown node id")
 
 func New(config Config) (Cluster, error) {
 	c := &cluster{
@@ -717,6 +718,14 @@ func (c *cluster) Leave(origin, id string) error {
 		id = c.nodeID
 	}
 
+	c.nodesLock.RLock()
+	_, hasNode := c.nodes[id]
+	c.nodesLock.RUnlock()
+
+	if !hasNode {
+		return ErrUnknownNode
+	}
+
 	c.logger.Debug().WithFields(log.Fields{
 		"nodeid": id,
 	}).Log("Received leave request for server")

http/handler/api/cluster.go

@@ -1,6 +1,7 @@
 package api
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -196,7 +197,14 @@ func (h *ClusterHandler) Leave(c echo.Context) error {
 		}
 	}
 
-	h.cluster.Leave("", nodeid.ID)
+	err = h.cluster.Leave("", nodeid.ID)
+	if err != nil {
+		if errors.Is(err, cluster.ErrUnknownNode) {
+			return api.Err(http.StatusNotFound, "", "node not found")
+		}
+
+		return api.Err(http.StatusInternalServerError, "", "%s", err.Error())
+	}
 
 	return c.JSON(http.StatusOK, "OK")
 }