66 lines
1.7 KiB
Go
66 lines
1.7 KiB
Go
// Copyright 2015 The etcd Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package client
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import (
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"fmt"
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"net"
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"net/url"
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)
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var (
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// indirection for testing
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lookupSRV = net.LookupSRV
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)
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type srvDiscover struct{}
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// NewSRVDiscover constructs a new Discoverer that uses the stdlib to lookup SRV records.
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func NewSRVDiscover() Discoverer {
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return &srvDiscover{}
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}
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// Discover looks up the etcd servers for the domain.
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func (d *srvDiscover) Discover(domain string) ([]string, error) {
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var urls []*url.URL
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updateURLs := func(service, scheme string) error {
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_, addrs, err := lookupSRV(service, "tcp", domain)
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if err != nil {
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return err
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}
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for _, srv := range addrs {
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urls = append(urls, &url.URL{
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Scheme: scheme,
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Host: net.JoinHostPort(srv.Target, fmt.Sprintf("%d", srv.Port)),
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})
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}
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return nil
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}
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errHTTPS := updateURLs("etcd-client-ssl", "https")
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errHTTP := updateURLs("etcd-client", "http")
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if errHTTPS != nil && errHTTP != nil {
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return nil, fmt.Errorf("dns lookup errors: %s and %s", errHTTPS, errHTTP)
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}
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endpoints := make([]string, len(urls))
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for i := range urls {
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endpoints[i] = urls[i].String()
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}
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return endpoints, nil
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}
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