add hostname to network alias

We use the name as alias but using the hostname makes also sense and
this is what docker does. We have to keep the short id as well for
docker compat.

While adding some tests I removed some duplicated tests that were
executed twice for nv for no reason.

Fixes containers#17370

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Author: Luap99

libpod/networking_common.go

@@ -513,8 +513,7 @@ func (c *Container) NetworkConnect(nameOrID, netName string, netOpts types.PerNe
 	// get network status before we connect
 	networkStatus := c.getNetworkStatus()
 
-	// always add the short id as alias for docker compat
-	netOpts.Aliases = append(netOpts.Aliases, c.config.ID[:12])
+	netOpts.Aliases = append(netOpts.Aliases, getExtraNetworkAliases(c)...)
 
 	if netOpts.InterfaceName == "" {
 		netOpts.InterfaceName = getFreeInterfaceName(networks)
@@ -639,6 +638,16 @@ func getFreeInterfaceName(networks map[string]types.PerNetworkOptions) string {
 	return ""
 }
 
+func getExtraNetworkAliases(c *Container) []string {
+	// always add the short id as alias for docker compat
+	alias := []string{c.config.ID[:12]}
+	// if an explicit hostname was set add it as well
+	if c.config.Spec.Hostname != "" {
+		alias = append(alias, c.config.Spec.Hostname)
+	}
+	return alias
+}
+
 // DisconnectContainerFromNetwork removes a container from its network
 func (r *Runtime) DisconnectContainerFromNetwork(nameOrID, netName string, force bool) error {
 	ctr, err := r.LookupContainer(nameOrID)

libpod/runtime_ctr.go

@@ -282,8 +282,7 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 					return nil, errors.New("failed to find free network interface name")
 				}
 			}
-			// always add the short id as alias for docker compat
-			opts.Aliases = append(opts.Aliases, ctr.config.ID[:12])
+			opts.Aliases = append(opts.Aliases, getExtraNetworkAliases(ctr)...)
 
 			normalizeNetworks[netName] = opts
 		}

test/e2e/run_networking_test.go

@@ -1108,7 +1108,8 @@ EXPOSE 2004-2005/tcp`, ALPINE)
 		Expect(session).Should(Exit(0))
 
 		pod2 := "testpod2"
-		session = podmanTest.Podman([]string{"pod", "create", "--network", net, "--name", pod2})
+		hostname := "hostn1"
+		session = podmanTest.Podman([]string{"pod", "create", "--network", net, "--name", pod2, "--hostname", hostname})
 		session.WaitWithDefaultTimeout()
 		Expect(session).Should(Exit(0))
 
@@ -1128,40 +1129,8 @@ EXPOSE 2004-2005/tcp`, ALPINE)
 		session = podmanTest.Podman([]string{"run", "--name", "con4", "--network", net, ALPINE, "nslookup", pod2 + ".dns.podman"})
 		session.WaitWithDefaultTimeout()
 		Expect(session).Should(Exit(0))
-	})
-
-	It("podman run check dnsname plugin with Netavark", func() {
-		SkipIfCNI(podmanTest)
-		pod := "testpod"
-		session := podmanTest.Podman([]string{"pod", "create", "--name", pod})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(Exit(0))
-
-		net := createNetworkName("IntTest")
-		session = podmanTest.Podman([]string{"network", "create", net})
-		session.WaitWithDefaultTimeout()
-		defer podmanTest.removeNetwork(net)
-		Expect(session).Should(Exit(0))
-
-		pod2 := "testpod2"
-		session = podmanTest.Podman([]string{"pod", "create", "--network", net, "--name", pod2})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(Exit(0))
-
-		session = podmanTest.Podman([]string{"run", "--name", "con1", "--network", net, ALPINE, "nslookup", "con1"})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(Exit(0))
-
-		session = podmanTest.Podman([]string{"run", "--name", "con2", "--pod", pod, "--network", net, ALPINE, "nslookup", "con2"})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(Exit(0))
 
-		session = podmanTest.Podman([]string{"run", "--name", "con3", "--pod", pod2, ALPINE, "nslookup", "con1"})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(Exit(1))
-		Expect(session.ErrorToString()).To(ContainSubstring("can't resolve 'con1'"))
-
-		session = podmanTest.Podman([]string{"run", "--name", "con4", "--network", net, ALPINE, "nslookup", pod2 + ".dns.podman"})
+		session = podmanTest.Podman([]string{"run", "--network", net, ALPINE, "nslookup", hostname})
 		session.WaitWithDefaultTimeout()
 		Expect(session).Should(Exit(0))
 	})
@@ -1179,20 +1148,6 @@ EXPOSE 2004-2005/tcp`, ALPINE)
 		Expect(session.OutputToString()).To(ContainSubstring("search dns.podman"))
 	})
 
-	It("podman run check dnsname adds dns search domain with Netavark", func() {
-		SkipIfCNI(podmanTest)
-		net := createNetworkName("dnsname")
-		session := podmanTest.Podman([]string{"network", "create", net})
-		session.WaitWithDefaultTimeout()
-		defer podmanTest.removeNetwork(net)
-		Expect(session).Should(Exit(0))
-
-		session = podmanTest.Podman([]string{"run", "--network", net, ALPINE, "cat", "/etc/resolv.conf"})
-		session.WaitWithDefaultTimeout()
-		Expect(session).Should(Exit(0))
-		Expect(session.OutputToString()).To(ContainSubstring("search dns.podman"))
-	})
-
 	It("Rootless podman run with --net=bridge works and connects to default network", func() {
 		// This is harmless when run as root, so we'll just let it run.
 		ctrName := "testctr"

test/system/500-networking.bats

@@ -471,8 +471,10 @@ load helpers.network
     run_podman run -d --network $netname $IMAGE top
     background_cid=$output
 
+    local hostname=host-$(random_string 10)
     # Run a httpd container on first network with exposed port
     run_podman run -d -p "$HOST_PORT:80" \
+            --hostname $hostname \
             --network $netname \
             -v $INDEX1:/var/www/index.txt:Z \
             -w /var/www \
@@ -490,7 +492,7 @@ load helpers.network
 
     # check network alias for container short id
     run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname\").Aliases}}"
-    is "$output" "[${cid:0:12}]" "short container id in network aliases"
+    is "$output" "[${cid:0:12} $hostname]" "short container id and hostname in network aliases"
 
     # check /etc/hosts for our entry
     run_podman exec $cid cat /etc/hosts
@@ -550,7 +552,7 @@ load helpers.network
 
     # check network2 alias for container short id
     run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname2\").Aliases}}"
-    is "$output" "[${cid:0:12}]" "short container id in network aliases"
+    is "$output" "[${cid:0:12} $hostname]" "short container id and hostname in network2 aliases"
 
     # curl should work
     run curl --max-time 3 -s $SERVER/index.txt