add registry base interface, mdns, noop implementations, add resolver, client

utils/net/net.go

@@ -0,0 +1,120 @@
+package net
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// HostPort format addr and port suitable for dial
+func HostPort(addr string, port interface{}) string {
+	host := addr
+	if strings.Count(addr, ":") > 0 {
+		host = fmt.Sprintf("[%s]", addr)
+	}
+	// when port is blank or 0, host is a queue name
+	if v, ok := port.(string); ok && v == "" {
+		return host
+	} else if v, ok := port.(int); ok && v == 0 && net.ParseIP(host) == nil {
+		return host
+	}
+
+	return fmt.Sprintf("%s:%v", host, port)
+}
+
+// Listen takes addr:portmin-portmax and binds to the first available port
+// Example: Listen("localhost:5000-6000", fn)
+func Listen(addr string, fn func(string) (net.Listener, error)) (net.Listener, error) {
+
+	if strings.Count(addr, ":") == 1 && strings.Count(addr, "-") == 0 {
+		return fn(addr)
+	}
+
+	// host:port || host:min-max
+	host, ports, err := net.SplitHostPort(addr)
+	if err != nil {
+		return nil, err
+	}
+
+	// try to extract port range
+	prange := strings.Split(ports, "-")
+
+	// single port
+	if len(prange) < 2 {
+		return fn(addr)
+	}
+
+	// we have a port range
+
+	// extract min port
+	min, err := strconv.Atoi(prange[0])
+	if err != nil {
+		return nil, errors.New("unable to extract port range")
+	}
+
+	// extract max port
+	max, err := strconv.Atoi(prange[1])
+	if err != nil {
+		return nil, errors.New("unable to extract port range")
+	}
+
+	// range the ports
+	for port := min; port <= max; port++ {
+		// try bind to host:port
+		ln, err := fn(HostPort(host, port))
+		if err == nil {
+			return ln, nil
+		}
+
+		// hit max port
+		if port == max {
+			return nil, err
+		}
+	}
+
+	// why are we here?
+	return nil, fmt.Errorf("unable to bind to %s", addr)
+}
+
+// Proxy returns the proxy and the address if it exits
+func Proxy(service string, address []string) (string, []string, bool) {
+	var hasProxy bool
+
+	// get proxy. we parse out address if present
+	if prx := os.Getenv("MICRO_PROXY"); len(prx) > 0 {
+		// default name
+		if prx == "service" {
+			prx = "go.micro.proxy"
+			address = nil
+		}
+
+		// check if its an address
+		if v := strings.Split(prx, ":"); len(v) > 1 {
+			address = []string{prx}
+		}
+
+		service = prx
+		hasProxy = true
+
+		return service, address, hasProxy
+	}
+
+	if prx := os.Getenv("MICRO_NETWORK"); len(prx) > 0 {
+		// default name
+		if prx == "service" {
+			prx = "go.micro.network"
+		}
+		service = prx
+		hasProxy = true
+	}
+
+	if prx := os.Getenv("MICRO_NETWORK_ADDRESS"); len(prx) > 0 {
+		address = []string{prx}
+		hasProxy = true
+	}
+
+	return service, address, hasProxy
+}