Get outbound IP in multiple ways or disable cache server if failed to init (#74)

Fix #64 (incompletely).

It's still not ideal. It makes more sense to use the gateway IP address of container network as outbound IP of cache server. However, this requires act to cooperate, some think like:

- act creates the network for new container, and returns the network to runner.
- runner extracts the gateway IP in the network.
- runner uses the gateway IP as outbound IP, and pass it to act as cache server endpoint.
- act It continues to create the container with the created network.

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/74
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>

artifactcache/handler.go

@@ -18,7 +18,6 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/go-chi/render"
-	"github.com/nektos/act/pkg/common"
 	log "github.com/sirupsen/logrus"
 	_ "modernc.org/sqlite"
 	"xorm.io/builder"
@@ -39,6 +38,8 @@ type Handler struct {
 
 	gc   atomic.Bool
 	gcAt time.Time
+
+	outboundIP string
 }
 
 func NewHandler() (*Handler, error) {
@@ -69,6 +70,12 @@ func NewHandler() (*Handler, error) {
 	}
 	h.storage = storage
 
+	if ip, err := getOutboundIP(); err != nil {
+		return nil, err
+	} else {
+		h.outboundIP = ip.String()
+	}
+
 	router := chi.NewRouter()
 	router.Use(middleware.RequestLogger(&middleware.DefaultLogFormatter{Logger: logger}))
 	router.Use(func(handler http.Handler) http.Handler {
@@ -113,7 +120,7 @@ func NewHandler() (*Handler, error) {
 func (h *Handler) ExternalURL() string {
 	// TODO: make the external url configurable if necessary
 	return fmt.Sprintf("http://%s:%d",
-		common.GetOutboundIP().String(),
+		h.outboundIP,
 		h.listener.Addr().(*net.TCPAddr).Port)
 }
 

artifactcache/util.go

@@ -5,6 +5,7 @@ package artifactcache
 
 import (
 	"fmt"
+	"net"
 	"net/http"
 	"strconv"
 	"strings"
@@ -44,6 +45,33 @@ func parseContentRange(s string) (int64, int64, error) {
 	return start, stop, nil
 }
 
+func getOutboundIP() (net.IP, error) {
+	// FIXME: It makes more sense to use the gateway IP address of container network
+	if conn, err := net.Dial("udp", "8.8.8.8:80"); err == nil {
+		defer conn.Close()
+		return conn.LocalAddr().(*net.UDPAddr).IP, nil
+	}
+	if ifaces, err := net.Interfaces(); err == nil {
+		for _, i := range ifaces {
+			if addrs, err := i.Addrs(); err == nil {
+				for _, addr := range addrs {
+					var ip net.IP
+					switch v := addr.(type) {
+					case *net.IPNet:
+						ip = v.IP
+					case *net.IPAddr:
+						ip = v.IP
+					}
+					if ip.IsGlobalUnicast() {
+						return ip, nil
+					}
+				}
+			}
+		}
+	}
+	return nil, fmt.Errorf("no outbound IP address found")
+}
+
 // engine is a wrapper of *xorm.Engine, with a lock.
 // To avoid racing of sqlite, we don't care performance here.
 type engine struct {

cmd/daemon.go

@@ -49,12 +49,6 @@ func runDaemon(ctx context.Context, envFile string) func(cmd *cobra.Command, arg
 			}
 		}
 
-		handler, err := artifactcache.NewHandler()
-		if err != nil {
-			return err
-		}
-		log.Infof("cache handler listens on: %v", handler.ExternalURL())
-
 		var g errgroup.Group
 
 		cli := client.New(
@@ -72,7 +66,13 @@ func runDaemon(ctx context.Context, envFile string) func(cmd *cobra.Command, arg
 			Environ:       cfg.Runner.Environ,
 			Labels:        cfg.Runner.Labels,
 			Version:       version,
-			CacheHandler:  handler,
+		}
+
+		if handler, err := artifactcache.NewHandler(); err != nil {
+			log.Errorf("cannot init cache server, it will be disabled: %v", err)
+		} else {
+			log.Infof("cache handler listens on: %v", handler.ExternalURL())
+			runner.CacheHandler = handler
 		}
 
 		poller := poller.New(

runtime/runtime.go

@@ -27,7 +27,9 @@ func (s *Runner) Run(ctx context.Context, task *runnerv1.Task) error {
 	for k, v := range s.Environ {
 		env[k] = v
 	}
+	if s.CacheHandler != nil {
 		env["ACTIONS_CACHE_URL"] = s.CacheHandler.ExternalURL() + "/"
+	}
 	return NewTask(s.ForgeInstance, task.Id, s.Client, env, s.platformPicker).Run(ctx, task, s.Machine, s.Version)
 }