// LookupName returns a list of SRV records. addrPath is the path to a
// json file in zk. It can also reference a named port
// (/zk/cell/zkns/path:_named_port)
func LookupName(zconn zk.Conn, addrPath string) ([]*net.SRV, error) {
zkPathParts := strings.Split(addrPath, ":")
zkPath := zkPathParts[0]
namedPort := ""
if len(zkPathParts) == 2 {
namedPort = zkPathParts[1]
}
addrs, err := ReadAddrs(zconn, zkPath)
if err != nil {
return nil, fmt.Errorf("LookupName failed: %v", err)
}
if namedPort == "" {
if !addrs.IsValidA() && !addrs.IsValidCNAME() {
return nil, fmt.Errorf("LookupName named port required: %v", addrPath)
}
} else if !addrs.IsValidSRV() {
return nil, fmt.Errorf("LookupName invalid record: %v", addrPath)
}
isValidA := addrs.IsValidA()
srvs := make([]*net.SRV, 0, len(addrs.Entries))
for _, addr := range addrs.Entries {
// Set the weight to non-zero, otherwise the sort method is deactivated.
srv := &net.SRV{Target: addr.Host, Weight: 1}
if namedPort != "" {
srv.Port = uint16(addr.NamedPortMap[namedPort])
if srv.Port == 0 {
// If the port was requested and not defined it's probably
// a bug, so fail hard.
return nil, fmt.Errorf("LookupName found no such named port: %v", addrPath)
}
} else if isValidA {
srv.Target = addr.IPv4
}
srvs = append(srvs, srv)
}
netutil.SortRfc2782(srvs)
return srvs, nil
}
// SrvEntries converts EndPoints to net.SRV for a given port.
// FIXME(msolomon) merge with zkns
func SrvEntries(addrs *EndPoints, namedPort string) (srvs []*net.SRV, err error) {
srvs = make([]*net.SRV, 0, len(addrs.Entries))
var srvErr error
for _, entry := range addrs.Entries {
host := entry.Host
port := 0
if namedPort == "" {
namedPort = DefaultPortName
}
port = entry.NamedPortMap[namedPort]
if port == 0 {
log.Warningf("vtns: bad port %v %v", namedPort, entry)
continue
}
srvs = append(srvs, &net.SRV{Target: host, Port: uint16(port)})
}
netutil.SortRfc2782(srvs)
if srvErr != nil && len(srvs) == 0 {
return nil, fmt.Errorf("SrvEntries failed: no valid endpoints found")
}
return
}