forked from go-micro/go-micro
/
extractor.go
70 lines (57 loc) · 1.16 KB
/
extractor.go
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package broker
import (
"fmt"
"net"
)
var (
privateBlocks []*net.IPNet
)
func init() {
for _, b := range []string{"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"} {
if _, block, err := net.ParseCIDR(b); err == nil {
privateBlocks = append(privateBlocks, block)
}
}
}
func extractAddress(addr string) (string, error) {
if len(addr) > 0 && (addr != "0.0.0.0" && addr != "[::]") {
return addr, nil
}
addrs, err := net.InterfaceAddrs()
if err != nil {
return "", fmt.Errorf("Failed to get interface addresses! Err: %v", err)
}
var ipAddr []byte
for _, rawAddr := range addrs {
var ip net.IP
switch addr := rawAddr.(type) {
case *net.IPAddr:
ip = addr.IP
case *net.IPNet:
ip = addr.IP
default:
continue
}
if ip.To4() == nil {
continue
}
if !isPrivateIP(ip.String()) {
continue
}
ipAddr = ip
break
}
if ipAddr == nil {
return "", fmt.Errorf("No private IP address found, and explicit IP not provided")
}
return net.IP(ipAddr).String(), nil
}
func isPrivateIP(ipAddr string) bool {
ip := net.ParseIP(ipAddr)
for _, priv := range privateBlocks {
if priv.Contains(ip) {
return true
}
}
return false
}