go.etcd.io/etcd@v3.3.27+incompatible/etcdserver/api/v2http/capability.go (about)

     1  // Copyright 2015 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package v2http
    16  
    17  import (
    18  	"fmt"
    19  	"net/http"
    20  
    21  	"github.com/coreos/etcd/etcdserver/api"
    22  	"github.com/coreos/etcd/etcdserver/api/v2http/httptypes"
    23  )
    24  
    25  func capabilityHandler(c api.Capability, fn func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
    26  	return func(w http.ResponseWriter, r *http.Request) {
    27  		if !api.IsCapabilityEnabled(c) {
    28  			notCapable(w, r, c)
    29  			return
    30  		}
    31  		fn(w, r)
    32  	}
    33  }
    34  
    35  func notCapable(w http.ResponseWriter, r *http.Request, c api.Capability) {
    36  	herr := httptypes.NewHTTPError(http.StatusInternalServerError, fmt.Sprintf("Not capable of accessing %s feature during rolling upgrades.", c))
    37  	if err := herr.WriteTo(w); err != nil {
    38  		plog.Debugf("error writing HTTPError (%v) to %s", err, r.RemoteAddr)
    39  	}
    40  }