65 lines
1.8 KiB
Go
65 lines
1.8 KiB
Go
/*
|
|
Copyright 2021 The Dapr Authors
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package nameresolution
|
|
|
|
import (
|
|
"context"
|
|
"math/rand"
|
|
"strconv"
|
|
)
|
|
|
|
// Resolver is the interface of name resolver.
|
|
type Resolver interface {
|
|
// Init initializes name resolver.
|
|
Init(ctx context.Context, metadata Metadata) error
|
|
// ResolveID resolves name to address.
|
|
ResolveID(ctx context.Context, req ResolveRequest) (string, error)
|
|
}
|
|
|
|
// ResolverMulti is an optional interface for name resolvers that can return multiple addresses.
|
|
type ResolverMulti interface {
|
|
ResolveIDMulti(ctx context.Context, req ResolveRequest) (AddressList, error)
|
|
}
|
|
|
|
// ResolveRequest represents service discovery resolver request.
|
|
type ResolveRequest struct {
|
|
ID string
|
|
Namespace string
|
|
Port int
|
|
Data map[string]string
|
|
}
|
|
|
|
// CacheKey returns a string that can be used to identify this ResolveRequest in a cache
|
|
func (r ResolveRequest) CacheKey() string {
|
|
return r.Namespace + "/" + r.ID + "/" + strconv.Itoa(r.Port)
|
|
}
|
|
|
|
// AddressList is a list of addresses resolved by the nameresolver
|
|
type AddressList []string
|
|
|
|
// Pick returns a random address from the list
|
|
func (a AddressList) Pick() string {
|
|
l := len(a)
|
|
switch l {
|
|
case 0:
|
|
return ""
|
|
case 1:
|
|
return a[0]
|
|
default:
|
|
// We use math/rand here as we are just picking a random address, so we don't need a CSPRNG
|
|
//nolint:gosec
|
|
return a[rand.Intn(l)]
|
|
}
|
|
}
|