Merge pull request #29227 from ashley-cui/dnsnames

Add dnsnames field & fix alias field

libpod/define/container_inspect.go

@@ -739,8 +739,11 @@ type InspectAdditionalNetwork struct {
 	// Links is presently unused and maintained exclusively for
 	// compatibility.
 	Links []string `json:"Links"`
-	// Aliases are any network aliases the container has in this network.
+	// Aliases are user-provided network aliases the container has in this network.
 	Aliases []string `json:"Aliases,omitempty"`
+	// DNSNames contains the complete list of DNS names that resolve to this
+	// container, including the container name, user aliases, short ID, and hostname.
+	DNSNames []string `json:"DNSNames,omitempty"`
 }
 
 // InspectNetworkSettings holds information about the network settings of the

libpod/networking_common.go

@@ -70,6 +70,14 @@ func (c *Container) getNetworkOptions(networkOpts []types.NamedPerNetworkOptions
 	} else {
 		opts.Networks = networkOpts
 	}
+
+	// Alias should only include user-provided aliases. Append the auto-generated
+	// aliases (short ID, hostname) so the network backend creates DNS records
+	// for them. Concat allocates a new slice, avoiding mutation of the stored config.
+	for i := range opts.Networks {
+		opts.Networks[i].Aliases = slices.Concat(opts.Networks[i].Aliases, getExtraNetworkAliases(c))
+	}
+
 	return opts
 }
 
@@ -273,6 +281,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 				netInfo := new(define.InspectAdditionalNetwork)
 				netInfo.NetworkID = getNetworkID(net.Name)
 				netInfo.Aliases = net.Aliases
+				netInfo.DNSNames = c.dnsNamesForNetwork(net.Aliases)
 				settings.Networks[net.Name] = netInfo
 			}
 		} else {
@@ -305,6 +314,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 			addedNet := new(define.InspectAdditionalNetwork)
 			addedNet.NetworkID = getNetworkID(network.Name)
 			addedNet.Aliases = network.Aliases
+			addedNet.DNSNames = c.dnsNamesForNetwork(network.Aliases)
 			addedNet.InspectBasicNetworkConfig = resultToBasicNetworkConfig(result)
 
 			settings.Networks[network.Name] = addedNet
@@ -545,8 +555,6 @@ func (c *Container) NetworkConnect(nameOrID, netName string, netOpts types.PerNe
 	// get network status before we connect
 	networkStatus := c.getNetworkStatus()
 
-	netOpts.Aliases = append(netOpts.Aliases, getExtraNetworkAliases(c)...)
-
 	// check whether interface is to be named as the network_interface
 	// when name left unspecified
 	if netOpts.InterfaceName == "" {
@@ -560,6 +568,7 @@ func (c *Container) NetworkConnect(nameOrID, netName string, netOpts types.PerNe
 			return errors.New("could not find free network interface name")
 		}
 	}
+	netOpts.Aliases = slices.Compact(slices.Sorted(slices.Values(netOpts.Aliases)))
 	namedOpts := types.NamedPerNetworkOptions{
 		Name:              netName,
 		PerNetworkOptions: netOpts,
@@ -597,7 +606,9 @@ func (c *Container) NetworkConnect(nameOrID, netName string, netOpts types.PerNe
 		NetworkOrder:  append(networkNamesFromOpts(networks), netName),
 	}
 	opts.PortMappings = c.convertPortMappings()
-	opts.Networks = []types.NamedPerNetworkOptions{namedOpts}
+	setupOpts := namedOpts
+	setupOpts.Aliases = slices.Concat(setupOpts.Aliases, getExtraNetworkAliases(c))
+	opts.Networks = []types.NamedPerNetworkOptions{setupOpts}
 
 	results, err := c.runtime.setUpNetwork(c.state.NetNS, opts)
 	if err != nil {
@@ -701,6 +712,17 @@ func getExtraNetworkAliases(c *Container) []string {
 	return alias
 }
 
+func (c *Container) dnsNamesForNetwork(aliases []string) []string {
+	all := slices.Concat([]string{c.Name()}, aliases, getExtraNetworkAliases(c))
+	names := all[:0]
+	for _, n := range all {
+		if !slices.Contains(names, n) {
+			names = append(names, n)
+		}
+	}
+	return names
+}
+
 // 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

@@ -11,6 +11,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"slices"
 	"strings"
 	"time"
 
@@ -298,9 +299,8 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 					return nil, errors.New("failed to find free network interface name")
 				}
 			}
-			network.Aliases = append(network.Aliases, getExtraNetworkAliases(ctr)...)
-
 			network.Name = netName
+			network.Aliases = slices.Compact(slices.Sorted(slices.Values(network.Aliases)))
 			normalizeNetworks = append(normalizeNetworks, network)
 		}
 		ctr.config.Networks = normalizeNetworks

test/apiv2/20-containers.at

@@ -1007,3 +1007,32 @@ t GET containers/healthcheck-test-running/json 200 \
   .State.Health.Status="healthy"
 
 podman rm -f healthcheck-test-running
+
+#
+# Test DNSNames / Aliases field in container inspect
+#
+podman network create dnstest
+podman create --name dnscontainer --network dnstest --hostname myhostname --network-alias myalias $IMAGE top
+t GET containers/dnscontainer/json 200
+cid=$(jq -r '.Id' <<<"$output")
+short_id=${cid:0:12}
+
+# Compat API should return DNSNames and user-only Aliases
+t GET containers/dnscontainer/json 200 \
+  .NetworkSettings.Networks.dnstest.Aliases[0]=myalias \
+  .NetworkSettings.Networks.dnstest.DNSNames[0]=dnscontainer \
+  .NetworkSettings.Networks.dnstest.DNSNames[1]=myalias \
+  .NetworkSettings.Networks.dnstest.DNSNames[2]=$short_id \
+  .NetworkSettings.Networks.dnstest.DNSNames[3]=myhostname
+
+# Test network connect adds DNSNames but not short ID/hostname to Aliases
+podman network create dnstest2
+t POST networks/dnstest2/connect Container=dnscontainer 200
+t GET containers/dnscontainer/json 200 \
+  .NetworkSettings.Networks.dnstest2.Aliases=null \
+  .NetworkSettings.Networks.dnstest2.DNSNames[0]=dnscontainer \
+  .NetworkSettings.Networks.dnstest2.DNSNames[1]=$short_id
+
+# cleanup
+podman rm -f dnscontainer
+podman network rm -f dnstest dnstest2

test/e2e/container_inspect_test.go

@@ -140,4 +140,31 @@ var _ = Describe("Podman container inspect", func() {
 		Expect(data).To(HaveLen(1))
 		Expect(data[0].Config.Env).To(ContainElement(Equal(secretName + "=*******")))
 	})
+
+	It("podman inspect NetworkSettings DNSNames and Aliases", func() {
+		netName := "dnstest"
+		session := podmanTest.Podman([]string{"network", "create", netName})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(ExitCleanly())
+		defer podmanTest.removeNetwork(netName)
+
+		ctrName := "testdns"
+		session = podmanTest.Podman([]string{"create", "--name", ctrName, "--hostname", "myhostname", "--network", netName, "--network-alias", "myalias", ALPINE, "top"})
+		session.WaitWithDefaultTimeout()
+		Expect(session).Should(ExitCleanly())
+		cid := session.OutputToString()
+
+		data := podmanTest.InspectContainer(ctrName)
+		Expect(data).To(HaveLen(1))
+		Expect(data[0].NetworkSettings.Networks).To(HaveKey(netName))
+
+		network := data[0].NetworkSettings.Networks[netName]
+		// Aliases should only contain user-provided alias
+		Expect(network.Aliases).To(Equal([]string{"myalias"}))
+		// DNSNames should contain container name, user alias, short ID, and hostname
+		Expect(network.DNSNames).To(ContainElement(ctrName))
+		Expect(network.DNSNames).To(ContainElement("myalias"))
+		Expect(network.DNSNames).To(ContainElement(cid[0:12]))
+		Expect(network.DNSNames).To(ContainElement("myhostname"))
+	})
 })

test/e2e/network_connect_disconnect_test.go

@@ -115,11 +115,17 @@ var _ = Describe("Podman network connect and disconnect", func() {
 		Expect(ctr).Should(ExitCleanly())
 		cid := ctr.OutputToString()
 
-		// network alias container short id is always added and shown in inspect
+		// Aliases should be empty (no user-provided aliases)
 		inspect := podmanTest.Podman([]string{"container", "inspect", "test", "--format", "{{(index .NetworkSettings.Networks \"" + netName + "\").Aliases}}"})
 		inspect.WaitWithDefaultTimeout()
 		Expect(inspect).Should(ExitCleanly())
-		Expect(inspect.OutputToString()).To(Equal("[" + cid[0:12] + "]"))
+		Expect(inspect.OutputToString()).To(Equal("[]"))
+
+		// DNSNames should contain the short ID
+		inspect = podmanTest.Podman([]string{"container", "inspect", "test", "--format", "{{(index .NetworkSettings.Networks \"" + netName + "\").DNSNames}}"})
+		inspect.WaitWithDefaultTimeout()
+		Expect(inspect).Should(ExitCleanly())
+		Expect(inspect.OutputToString()).To(ContainSubstring(cid[0:12]))
 
 		con := podmanTest.Podman([]string{"network", "connect", netName, "test"})
 		con.WaitWithDefaultTimeout()
@@ -179,11 +185,17 @@ var _ = Describe("Podman network connect and disconnect", func() {
 		Expect(inspect).Should(ExitCleanly())
 		Expect(inspect.OutputToString()).To(Equal("2"))
 
-		// network alias container short id is always added and shown in inspect
+		// Aliases should be empty after network connect (no user-provided aliases)
 		inspect = podmanTest.Podman([]string{"container", "inspect", "test", "--format", "{{(index .NetworkSettings.Networks \"" + newNetName + "\").Aliases}}"})
 		inspect.WaitWithDefaultTimeout()
 		Expect(inspect).Should(ExitCleanly())
-		Expect(inspect.OutputToString()).To(Equal("[" + cid[0:12] + "]"))
+		Expect(inspect.OutputToString()).To(Equal("[]"))
+
+		// DNSNames should contain the short ID
+		inspect = podmanTest.Podman([]string{"container", "inspect", "test", "--format", "{{(index .NetworkSettings.Networks \"" + newNetName + "\").DNSNames}}"})
+		inspect.WaitWithDefaultTimeout()
+		Expect(inspect).Should(ExitCleanly())
+		Expect(inspect.OutputToString()).To(ContainSubstring(cid[0:12]))
 
 		exec = podmanTest.Podman([]string{"exec", "test", "ip", "addr", "show", "eth1"})
 		exec.WaitWithDefaultTimeout()

test/system/500-networking.bats

@@ -552,12 +552,13 @@ EOCONF
 
     run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname\").IPAddress}}
 {{(index .NetworkSettings.Networks \"$netname\").MacAddress}}
-{{(index .NetworkSettings.Networks \"$netname\").Aliases}}"
+{{(index .NetworkSettings.Networks \"$netname\").DNSNames}}"
     ip="${lines[0]}"
     mac="${lines[1]}"
 
-    # check network alias for container short id
-    is "${lines[2]}" "[${cid:0:12} $hostname]" "short container id and hostname in network aliases"
+    # check DNSNames for container short id and hostname
+    assert "${lines[2]}" =~ "${cid:0:12}" "short container id in DNSNames"
+    assert "${lines[2]}" =~ "$hostname" "hostname in DNSNames"
 
     # check /etc/hosts for our entry
     run_podman exec $cid cat /etc/hosts
@@ -615,9 +616,10 @@ EOCONF
     run_podman network connect $netname2 $cid
     is "$output" "" "Output should be empty (no errors)"
 
-    # check network2 alias for container short id
-    run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname2\").Aliases}}"
-    is "$output" "[${cid:0:12} $hostname]" "short container id and hostname in network2 aliases"
+    # check network2 DNSNames for container short id and hostname
+    run_podman inspect $cid --format "{{(index .NetworkSettings.Networks \"$netname2\").DNSNames}}"
+    assert "$output" =~ "${cid:0:12}" "short container id in network2 DNSNames"
+    assert "$output" =~ "$hostname" "hostname in network2 DNSNames"
 
     # curl should work
     run curl --max-time 3 -s -S $SERVER/index.txt