Merge pull request #23339 from Luap99/nc-e2e-flake

test/e2e: fix ncat tests

test/e2e/run_networking_test.go

@@ -3,10 +3,12 @@ package integration
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net"
 	"os"
 	"strconv"
 	"strings"
+	"sync"
 	"syscall"
 
 	"github.com/containernetworking/plugins/pkg/ns"
@@ -543,56 +545,58 @@ EXPOSE 2004-2005/tcp`, ALPINE)
 		}
 	})
 
-	It("podman run network bind to 127.0.0.1", func() {
+	for _, local := range []bool{true, false} {
-		slirp4netnsHelp := SystemExec("slirp4netns", []string{"--help"})
+		local := local
-		Expect(slirp4netnsHelp).Should(ExitCleanly())
+		testName := "HostIP"
-		networkConfiguration := "slirp4netns:outbound_addr=127.0.0.1,allow_host_loopback=true"
+		if local {
-		port := strconv.Itoa(GetPort())
+			testName = "127.0.0.1"
-
-		if strings.Contains(slirp4netnsHelp.OutputToString(), "outbound-addr") {
-			ncListener := StartSystemExec("nc", []string{"-v", "-n", "-l", "-p", port})
-			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, "-dt", ALPINE, "nc", "-w", "2", "10.0.2.2", port})
-			session.WaitWithDefaultTimeout()
-			ncListener.WaitWithDefaultTimeout()
-
-			Expect(session).Should(ExitCleanly())
-			Expect(ncListener).Should(Exit(0))
-			Expect(ncListener.ErrorToString()).To(ContainSubstring("Connection from 127.0.0.1"))
-		} else {
-			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, "-dt", ALPINE, "nc", "-w", "2", "10.0.2.2", port})
-			session.WaitWithDefaultTimeout()
-			Expect(session).To(ExitWithError(125, "outbound_addr not supported"))
 		}
-	})
+		It(fmt.Sprintf("podman run network slirp4netns bind to %s", testName), func() {
-
+			ip := "127.0.0.1"
-	It("podman run network bind to HostIP", func() {
+			if !local {
 				// Determine our likeliest outgoing IP address
 				conn, err := net.Dial("udp", "8.8.8.8:80")
 				Expect(err).ToNot(HaveOccurred())
 
 				defer conn.Close()
-		ip := conn.LocalAddr().(*net.UDPAddr).IP
+				ip = conn.LocalAddr().(*net.UDPAddr).IP.String()
+			}
 			port := strconv.Itoa(GetPort())
 
-		slirp4netnsHelp := SystemExec("slirp4netns", []string{"--help"})
+			networkConfiguration := fmt.Sprintf("slirp4netns:outbound_addr=%s,allow_host_loopback=true", ip)
-		Expect(slirp4netnsHelp).Should(ExitCleanly())
-		networkConfiguration := fmt.Sprintf("slirp4netns:outbound_addr=%s,allow_host_loopback=true", ip.String())
 
-		if strings.Contains(slirp4netnsHelp.OutputToString(), "outbound-addr") {
+			listener, err := net.Listen("tcp", ":"+port)
-			ncListener := StartSystemExec("nc", []string{"-v", "-n", "-l", "-p", port})
+			Expect(err).ToNot(HaveOccurred())
-			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, ALPINE, "nc", "-w", "2", "10.0.2.2", port})
+			defer listener.Close()
-			session.Wait(30)
-			ncListener.Wait(30)
 
+			msg := RandomString(10)
+			wg := &sync.WaitGroup{}
+			wg.Add(1)
+			// now use a new goroutine to start accepting connection in the background and make the checks there
+			go func() {
+				defer GinkgoRecover()
+				defer wg.Done()
+				conn, err := listener.Accept()
+				Expect(err).ToNot(HaveOccurred(), "accept new connection")
+				defer conn.Close()
+				addr := conn.RemoteAddr()
+				// addr will be in the form ip:port, we don't care about the port as it is random
+				Expect(addr.String()).To(HavePrefix(ip+":"), "remote address")
+				gotBytes, err := io.ReadAll(conn)
+				Expect(err).ToNot(HaveOccurred(), "read from connection")
+				Expect(string(gotBytes)).To(Equal(msg), "received correct message from container")
+			}()
+
+			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, ALPINE, "sh", "-c", "echo -n " + msg + " | nc -w 30 10.0.2.2 " + port})
+			session.WaitWithDefaultTimeout()
 			Expect(session).Should(ExitCleanly())
-			Expect(ncListener).Should(Exit(0))
+
-			Expect(ncListener.ErrorToString()).To(ContainSubstring("Connection from " + ip.String()))
+			// explicitly close the socket here before we wait to unlock Accept() calls in case of hangs
-		} else {
+			listener.Close()
-			session := podmanTest.Podman([]string{"run", "--network", networkConfiguration, ALPINE, "nc", "-w", "2", "10.0.2.2", port})
+			// wait for the checks in the goroutine to be done
-			session.Wait(30)
+			wg.Wait()
-			Expect(session).To(ExitWithError(125, "outbound_addr not supported"))
-		}
 		})
+	}
 
 	It("podman run network expose ports in image metadata", func() {
 		session := podmanTest.Podman([]string{"create", "--name", "test", "-t", "-P", NGINX_IMAGE})