Initial commit

vendor/github.com/hyperhq/hypercli/pkg/discovery/backends.go

@@ -0,0 +1,107 @@
+package discovery
+
+import (
+	"fmt"
+	"net"
+	"strings"
+	"time"
+
+	log "github.com/Sirupsen/logrus"
+)
+
+var (
+	// Backends is a global map of discovery backends indexed by their
+	// associated scheme.
+	backends = make(map[string]Backend)
+)
+
+// Register makes a discovery backend available by the provided scheme.
+// If Register is called twice with the same scheme an error is returned.
+func Register(scheme string, d Backend) error {
+	if _, exists := backends[scheme]; exists {
+		return fmt.Errorf("scheme already registered %s", scheme)
+	}
+	log.WithField("name", scheme).Debug("Registering discovery service")
+	backends[scheme] = d
+	return nil
+}
+
+func parse(rawurl string) (string, string) {
+	parts := strings.SplitN(rawurl, "://", 2)
+
+	// nodes:port,node2:port => nodes://node1:port,node2:port
+	if len(parts) == 1 {
+		return "nodes", parts[0]
+	}
+	return parts[0], parts[1]
+}
+
+// ParseAdvertise parses the --cluster-advertise daemon config which accepts
+// <ip-address>:<port> or <interface-name>:<port>
+func ParseAdvertise(advertise string) (string, error) {
+	var (
+		iface *net.Interface
+		addrs []net.Addr
+		err   error
+	)
+
+	addr, port, err := net.SplitHostPort(advertise)
+
+	if err != nil {
+		return "", fmt.Errorf("invalid --cluster-advertise configuration: %s: %v", advertise, err)
+	}
+
+	ip := net.ParseIP(addr)
+	// If it is a valid ip-address, use it as is
+	if ip != nil {
+		return advertise, nil
+	}
+
+	// If advertise is a valid interface name, get the valid ipv4 address and use it to advertise
+	ifaceName := addr
+	iface, err = net.InterfaceByName(ifaceName)
+	if err != nil {
+		return "", fmt.Errorf("invalid cluster advertise IP address or interface name (%s) : %v", advertise, err)
+	}
+
+	addrs, err = iface.Addrs()
+	if err != nil {
+		return "", fmt.Errorf("unable to get advertise IP address from interface (%s) : %v", advertise, err)
+	}
+
+	if addrs == nil || len(addrs) == 0 {
+		return "", fmt.Errorf("no available advertise IP address in interface (%s)", advertise)
+	}
+
+	addr = ""
+	for _, a := range addrs {
+		ip, _, err := net.ParseCIDR(a.String())
+		if err != nil {
+			return "", fmt.Errorf("error deriving advertise ip-address in interface (%s) : %v", advertise, err)
+		}
+		if ip.To4() == nil || ip.IsLoopback() {
+			continue
+		}
+		addr = ip.String()
+		break
+	}
+	if addr == "" {
+		return "", fmt.Errorf("couldnt find a valid ip-address in interface %s", advertise)
+	}
+
+	addr = fmt.Sprintf("%s:%s", addr, port)
+	return addr, nil
+}
+
+// New returns a new Discovery given a URL, heartbeat and ttl settings.
+// Returns an error if the URL scheme is not supported.
+func New(rawurl string, heartbeat time.Duration, ttl time.Duration, clusterOpts map[string]string) (Backend, error) {
+	scheme, uri := parse(rawurl)
+	if backend, exists := backends[scheme]; exists {
+		log.WithFields(log.Fields{"name": scheme, "uri": uri}).Debug("Initializing discovery service")
+		err := backend.Initialize(uri, heartbeat, ttl, clusterOpts)
+		return backend, err
+	}
+
+	return nil, ErrNotSupported
+}