From 8c12c6939aab9106db14ec2d11d983bc5b29fb2c Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 7 Jul 2019 21:33:44 +0100 Subject: Switch to modules --- .../google.golang.org/grpc/naming/dns_resolver.go | 290 --------------------- 1 file changed, 290 deletions(-) delete mode 100644 vendor/google.golang.org/grpc/naming/dns_resolver.go (limited to 'vendor/google.golang.org/grpc/naming/dns_resolver.go') diff --git a/vendor/google.golang.org/grpc/naming/dns_resolver.go b/vendor/google.golang.org/grpc/naming/dns_resolver.go deleted file mode 100644 index 0f8a908..0000000 --- a/vendor/google.golang.org/grpc/naming/dns_resolver.go +++ /dev/null @@ -1,290 +0,0 @@ -/* - * - * Copyright 2017 gRPC 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 naming - -import ( - "errors" - "fmt" - "net" - "strconv" - "time" - - "golang.org/x/net/context" - "google.golang.org/grpc/grpclog" -) - -const ( - defaultPort = "443" - defaultFreq = time.Minute * 30 -) - -var ( - errMissingAddr = errors.New("missing address") - errWatcherClose = errors.New("watcher has been closed") -) - -// NewDNSResolverWithFreq creates a DNS Resolver that can resolve DNS names, and -// create watchers that poll the DNS server using the frequency set by freq. -func NewDNSResolverWithFreq(freq time.Duration) (Resolver, error) { - return &dnsResolver{freq: freq}, nil -} - -// NewDNSResolver creates a DNS Resolver that can resolve DNS names, and create -// watchers that poll the DNS server using the default frequency defined by defaultFreq. -func NewDNSResolver() (Resolver, error) { - return NewDNSResolverWithFreq(defaultFreq) -} - -// dnsResolver handles name resolution for names following the DNS scheme -type dnsResolver struct { - // frequency of polling the DNS server that the watchers created by this resolver will use. - freq time.Duration -} - -// formatIP returns ok = false if addr is not a valid textual representation of an IP address. -// If addr is an IPv4 address, return the addr and ok = true. -// If addr is an IPv6 address, return the addr enclosed in square brackets and ok = true. -func formatIP(addr string) (addrIP string, ok bool) { - ip := net.ParseIP(addr) - if ip == nil { - return "", false - } - if ip.To4() != nil { - return addr, true - } - return "[" + addr + "]", true -} - -// parseTarget takes the user input target string, returns formatted host and port info. -// If target doesn't specify a port, set the port to be the defaultPort. -// If target is in IPv6 format and host-name is enclosed in sqarue brackets, brackets -// are strippd when setting the host. -// examples: -// target: "www.google.com" returns host: "www.google.com", port: "443" -// target: "ipv4-host:80" returns host: "ipv4-host", port: "80" -// target: "[ipv6-host]" returns host: "ipv6-host", port: "443" -// target: ":80" returns host: "localhost", port: "80" -// target: ":" returns host: "localhost", port: "443" -func parseTarget(target string) (host, port string, err error) { - if target == "" { - return "", "", errMissingAddr - } - - if ip := net.ParseIP(target); ip != nil { - // target is an IPv4 or IPv6(without brackets) address - return target, defaultPort, nil - } - if host, port, err := net.SplitHostPort(target); err == nil { - // target has port, i.e ipv4-host:port, [ipv6-host]:port, host-name:port - if host == "" { - // Keep consistent with net.Dial(): If the host is empty, as in ":80", the local system is assumed. - host = "localhost" - } - if port == "" { - // If the port field is empty(target ends with colon), e.g. "[::1]:", defaultPort is used. - port = defaultPort - } - return host, port, nil - } - if host, port, err := net.SplitHostPort(target + ":" + defaultPort); err == nil { - // target doesn't have port - return host, port, nil - } - return "", "", fmt.Errorf("invalid target address %v", target) -} - -// Resolve creates a watcher that watches the name resolution of the target. -func (r *dnsResolver) Resolve(target string) (Watcher, error) { - host, port, err := parseTarget(target) - if err != nil { - return nil, err - } - - if net.ParseIP(host) != nil { - ipWatcher := &ipWatcher{ - updateChan: make(chan *Update, 1), - } - host, _ = formatIP(host) - ipWatcher.updateChan <- &Update{Op: Add, Addr: host + ":" + port} - return ipWatcher, nil - } - - ctx, cancel := context.WithCancel(context.Background()) - return &dnsWatcher{ - r: r, - host: host, - port: port, - ctx: ctx, - cancel: cancel, - t: time.NewTimer(0), - }, nil -} - -// dnsWatcher watches for the name resolution update for a specific target -type dnsWatcher struct { - r *dnsResolver - host string - port string - // The latest resolved address set - curAddrs map[string]*Update - ctx context.Context - cancel context.CancelFunc - t *time.Timer -} - -// ipWatcher watches for the name resolution update for an IP address. -type ipWatcher struct { - updateChan chan *Update -} - -// Next returns the address resolution Update for the target. For IP address, -// the resolution is itself, thus polling name server is unnecessary. Therefore, -// Next() will return an Update the first time it is called, and will be blocked -// for all following calls as no Update exists until watcher is closed. -func (i *ipWatcher) Next() ([]*Update, error) { - u, ok := <-i.updateChan - if !ok { - return nil, errWatcherClose - } - return []*Update{u}, nil -} - -// Close closes the ipWatcher. -func (i *ipWatcher) Close() { - close(i.updateChan) -} - -// AddressType indicates the address type returned by name resolution. -type AddressType uint8 - -const ( - // Backend indicates the server is a backend server. - Backend AddressType = iota - // GRPCLB indicates the server is a grpclb load balancer. - GRPCLB -) - -// AddrMetadataGRPCLB contains the information the name resolver for grpclb should provide. The -// name resolver used by the grpclb balancer is required to provide this type of metadata in -// its address updates. -type AddrMetadataGRPCLB struct { - // AddrType is the type of server (grpc load balancer or backend). - AddrType AddressType - // ServerName is the name of the grpc load balancer. Used for authentication. - ServerName string -} - -// compileUpdate compares the old resolved addresses and newly resolved addresses, -// and generates an update list -func (w *dnsWatcher) compileUpdate(newAddrs map[string]*Update) []*Update { - var res []*Update - for a, u := range w.curAddrs { - if _, ok := newAddrs[a]; !ok { - u.Op = Delete - res = append(res, u) - } - } - for a, u := range newAddrs { - if _, ok := w.curAddrs[a]; !ok { - res = append(res, u) - } - } - return res -} - -func (w *dnsWatcher) lookupSRV() map[string]*Update { - newAddrs := make(map[string]*Update) - _, srvs, err := lookupSRV(w.ctx, "grpclb", "tcp", w.host) - if err != nil { - grpclog.Infof("grpc: failed dns SRV record lookup due to %v.\n", err) - return nil - } - for _, s := range srvs { - lbAddrs, err := lookupHost(w.ctx, s.Target) - if err != nil { - grpclog.Warningf("grpc: failed load banlacer address dns lookup due to %v.\n", err) - continue - } - for _, a := range lbAddrs { - a, ok := formatIP(a) - if !ok { - grpclog.Errorf("grpc: failed IP parsing due to %v.\n", err) - continue - } - addr := a + ":" + strconv.Itoa(int(s.Port)) - newAddrs[addr] = &Update{Addr: addr, - Metadata: AddrMetadataGRPCLB{AddrType: GRPCLB, ServerName: s.Target}} - } - } - return newAddrs -} - -func (w *dnsWatcher) lookupHost() map[string]*Update { - newAddrs := make(map[string]*Update) - addrs, err := lookupHost(w.ctx, w.host) - if err != nil { - grpclog.Warningf("grpc: failed dns A record lookup due to %v.\n", err) - return nil - } - for _, a := range addrs { - a, ok := formatIP(a) - if !ok { - grpclog.Errorf("grpc: failed IP parsing due to %v.\n", err) - continue - } - addr := a + ":" + w.port - newAddrs[addr] = &Update{Addr: addr} - } - return newAddrs -} - -func (w *dnsWatcher) lookup() []*Update { - newAddrs := w.lookupSRV() - if newAddrs == nil { - // If failed to get any balancer address (either no corresponding SRV for the - // target, or caused by failure during resolution/parsing of the balancer target), - // return any A record info available. - newAddrs = w.lookupHost() - } - result := w.compileUpdate(newAddrs) - w.curAddrs = newAddrs - return result -} - -// Next returns the resolved address update(delta) for the target. If there's no -// change, it will sleep for 30 mins and try to resolve again after that. -func (w *dnsWatcher) Next() ([]*Update, error) { - for { - select { - case <-w.ctx.Done(): - return nil, errWatcherClose - case <-w.t.C: - } - result := w.lookup() - // Next lookup should happen after an interval defined by w.r.freq. - w.t.Reset(w.r.freq) - if len(result) > 0 { - return result, nil - } - } -} - -func (w *dnsWatcher) Close() { - w.cancel() -} -- cgit v1.2.3