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Merge pull request #47705 from robmry/backport-26.0/47662_ipvlan_l3_dns
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[26.0 backport] Enable external DNS for ipvlan-l3, and disable it for macvlan/ipvlan with no parent interface
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@vvoland
vvoland committed Apr 10, 2024
2 parents ed752f6 + 8ad7f86 commit 60b9add
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Showing 12 changed files with 417 additions and 145 deletions.
66 changes: 66 additions & 0 deletions integration/internal/network/dns.go
View file
@@ -0,0 +1,66 @@
package network

import (
"net"
"os"
"testing"

"github.com/miekg/dns"
"gotest.tools/v3/assert"
)

const DNSRespAddr = "10.11.12.13"

// WriteTempResolvConf writes a resolv.conf that only contains a single
// nameserver line, with address addr.
// It returns the name of the temp file. The temp file will be deleted
// automatically by a t.Cleanup().
func WriteTempResolvConf(t *testing.T, addr string) string {
t.Helper()
// Not using t.TempDir() here because in rootless mode, while the temporary
// directory gets mode 0777, it's a subdir of an 0700 directory owned by root.
// So, it's not accessible by the daemon.
f, err := os.CreateTemp("", "resolv.conf")
assert.NilError(t, err)
t.Cleanup(func() { os.Remove(f.Name()) })
err = f.Chmod(0644)
assert.NilError(t, err)
f.Write([]byte("nameserver " + addr + "\n"))
return f.Name()
}

// StartDaftDNS starts and returns a really, really daft DNS server that only
// responds to type-A requests, and always with address dnsRespAddr.
// The DNS server will be stopped automatically by a t.Cleanup().
func StartDaftDNS(t *testing.T, addr string) {
serveDNS := func(w dns.ResponseWriter, query *dns.Msg) {
if query.Question[0].Qtype == dns.TypeA {
resp := &dns.Msg{}
resp.SetReply(query)
answer := &dns.A{
Hdr: dns.RR_Header{
Name: query.Question[0].Name,
Rrtype: dns.TypeA,
Class: dns.ClassINET,
Ttl: 600,
},
}
answer.A = net.ParseIP(DNSRespAddr)
resp.Answer = append(resp.Answer, answer)
_ = w.WriteMsg(resp)
}
}

conn, err := net.ListenUDP("udp", &net.UDPAddr{
IP: net.ParseIP(addr),
Port: 53,
})
assert.NilError(t, err)

server := &dns.Server{Handler: dns.HandlerFunc(serveDNS), PacketConn: conn}
go func() {
_ = server.ActivateAndServe()
}()

t.Cleanup(func() { server.Shutdown() })
}
216 changes: 159 additions & 57 deletions integration/network/ipvlan/ipvlan_test.go
View file
Expand Up @@ -4,26 +4,27 @@ package ipvlan // import "github.com/docker/docker/integration/network/ipvlan"

import (
"context"
"os"
"os/exec"
"fmt"
"strings"
"sync"
"testing"

"github.com/docker/docker/api/types"
containertypes "github.com/docker/docker/api/types/container"
dclient "github.com/docker/docker/client"
"github.com/docker/docker/integration/internal/container"
net "github.com/docker/docker/integration/internal/network"
n "github.com/docker/docker/integration/network"
"github.com/docker/docker/testutil"
"github.com/docker/docker/testutil/daemon"
"gotest.tools/v3/assert"
is "gotest.tools/v3/assert/cmp"
"gotest.tools/v3/skip"
)

func TestDockerNetworkIpvlanPersistance(t *testing.T) {
// verify the driver automatically provisions the 802.1q link (di-dummy0.70)
skip.If(t, testEnv.IsRemoteDaemon)
skip.If(t, !ipvlanKernelSupport(t), "Kernel doesn't support ipvlan")
skip.If(t, testEnv.IsRootless, "rootless mode has different view of network")

ctx := testutil.StartSpan(baseContext, t)

Expand Down Expand Up @@ -52,7 +53,7 @@ func TestDockerNetworkIpvlanPersistance(t *testing.T) {

func TestDockerNetworkIpvlan(t *testing.T) {
skip.If(t, testEnv.IsRemoteDaemon)
skip.If(t, !ipvlanKernelSupport(t), "Kernel doesn't support ipvlan")
skip.If(t, testEnv.IsRootless, "rootless mode has different view of network")

ctx := testutil.StartSpan(baseContext, t)

Expand All @@ -79,14 +80,20 @@ func TestDockerNetworkIpvlan(t *testing.T) {
name: "L3InternalMode",
test: testIpvlanL3InternalMode,
}, {
name: "L2MultiSubnet",
test: testIpvlanL2MultiSubnet,
name: "L2MultiSubnetWithParent",
test: testIpvlanL2MultiSubnetWithParent,
}, {
name: "L2MultiSubnetNoParent",
test: testIpvlanL2MultiSubnetNoParent,
}, {
name: "L3MultiSubnet",
test: testIpvlanL3MultiSubnet,
}, {
name: "Addressing",
test: testIpvlanAddressing,
name: "L2Addressing",
test: testIpvlanL2Addressing,
}, {
name: "L3Addressing",
test: testIpvlanL3Addressing,
},
} {

Expand Down Expand Up @@ -225,10 +232,21 @@ func testIpvlanL3InternalMode(t *testing.T, ctx context.Context, client dclient.
assert.NilError(t, err)
}

func testIpvlanL2MultiSubnet(t *testing.T, ctx context.Context, client dclient.APIClient) {
func testIpvlanL2MultiSubnetWithParent(t *testing.T, ctx context.Context, client dclient.APIClient) {
const parentIfName = "di-dummy0"
n.CreateMasterDummy(ctx, t, parentIfName)
defer n.DeleteInterface(ctx, t, parentIfName)
testIpvlanL2MultiSubnet(t, ctx, client, parentIfName)
}

func testIpvlanL2MultiSubnetNoParent(t *testing.T, ctx context.Context, client dclient.APIClient) {
testIpvlanL2MultiSubnet(t, ctx, client, "")
}

func testIpvlanL2MultiSubnet(t *testing.T, ctx context.Context, client dclient.APIClient, parent string) {
netName := "dualstackl2"
net.CreateNoError(ctx, t, client, netName,
net.WithIPvlan("", ""),
net.WithIPvlan(parent, ""),
net.WithIPv6(),
net.WithIPAM("172.28.200.0/24", ""),
net.WithIPAM("172.28.202.0/24", "172.28.202.254"),
Expand All @@ -250,11 +268,22 @@ func testIpvlanL2MultiSubnet(t *testing.T, ctx context.Context, client dclient.A
)
c1, err := client.ContainerInspect(ctx, id1)
assert.NilError(t, err)
if parent == "" {
// Inspect the v4 gateway to ensure no default GW was assigned
assert.Check(t, is.Equal(c1.NetworkSettings.Networks[netName].Gateway, ""))
// Inspect the v6 gateway to ensure no default GW was assigned
assert.Check(t, is.Equal(c1.NetworkSettings.Networks[netName].IPv6Gateway, ""))
} else {
// Inspect the v4 gateway to ensure the proper default GW was assigned
assert.Check(t, is.Equal(c1.NetworkSettings.Networks[netName].Gateway, "172.28.200.1"))
// Inspect the v6 gateway to ensure the proper default GW was assigned
assert.Check(t, is.Equal(c1.NetworkSettings.Networks[netName].IPv6Gateway, "2001:db8:abc8::1"))
}

// verify ipv4 connectivity to the explicit --ipv address second to first
// verify ipv4 connectivity to the explicit --ip address second to first
_, err = container.Exec(ctx, client, id2, []string{"ping", "-c", "1", c1.NetworkSettings.Networks[netName].IPAddress})
assert.NilError(t, err)
// verify ipv6 connectivity to the explicit --ipv6 address second to first
// verify ipv6 connectivity to the explicit --ip6 address second to first
_, err = container.Exec(ctx, client, id2, []string{"ping6", "-c", "1", c1.NetworkSettings.Networks[netName].GlobalIPv6Address})
assert.NilError(t, err)

Expand All @@ -271,22 +300,24 @@ func testIpvlanL2MultiSubnet(t *testing.T, ctx context.Context, client dclient.A
)
c3, err := client.ContainerInspect(ctx, id3)
assert.NilError(t, err)
if parent == "" {
// Inspect the v4 gateway to ensure no default GW was assigned
assert.Check(t, is.Equal(c3.NetworkSettings.Networks[netName].Gateway, ""))
// Inspect the v6 gateway to ensure no default GW was assigned
assert.Check(t, is.Equal(c3.NetworkSettings.Networks[netName].IPv6Gateway, ""))
} else {
// Inspect the v4 gateway to ensure the proper explicitly assigned default GW was assigned
assert.Check(t, is.Equal(c3.NetworkSettings.Networks[netName].Gateway, "172.28.202.254"))
// Inspect the v6 gateway to ensure the proper explicitly assigned default GW was assigned
assert.Check(t, is.Equal(c3.NetworkSettings.Networks[netName].IPv6Gateway, "2001:db8:abc6::254"))
}

// verify ipv4 connectivity to the explicit --ipv address from third to fourth
// verify ipv4 connectivity to the explicit --ip address from third to fourth
_, err = container.Exec(ctx, client, id4, []string{"ping", "-c", "1", c3.NetworkSettings.Networks[netName].IPAddress})
assert.NilError(t, err)
// verify ipv6 connectivity to the explicit --ipv6 address from third to fourth
// verify ipv6 connectivity to the explicit --ip6 address from third to fourth
_, err = container.Exec(ctx, client, id4, []string{"ping6", "-c", "1", c3.NetworkSettings.Networks[netName].GlobalIPv6Address})
assert.NilError(t, err)

// Inspect the v4 gateway to ensure the proper default GW was assigned
assert.Equal(t, c1.NetworkSettings.Networks[netName].Gateway, "172.28.200.1")
// Inspect the v6 gateway to ensure the proper default GW was assigned
assert.Equal(t, c1.NetworkSettings.Networks[netName].IPv6Gateway, "2001:db8:abc8::1")
// Inspect the v4 gateway to ensure the proper explicitly assigned default GW was assigned
assert.Equal(t, c3.NetworkSettings.Networks[netName].Gateway, "172.28.202.254")
// Inspect the v6 gateway to ensure the proper explicitly assigned default GW was assigned
assert.Equal(t, c3.NetworkSettings.Networks[netName].IPv6Gateway, "2001:db8:abc6::254")
}

func testIpvlanL3MultiSubnet(t *testing.T, ctx context.Context, client dclient.APIClient) {
Expand Down Expand Up @@ -353,70 +384,141 @@ func testIpvlanL3MultiSubnet(t *testing.T, ctx context.Context, client dclient.A
assert.Equal(t, c3.NetworkSettings.Networks[netName].IPv6Gateway, "")
}

func testIpvlanAddressing(t *testing.T, ctx context.Context, client dclient.APIClient) {
// Verify ipvlan l2 mode sets the proper default gateway routes via netlink
// for either an explicitly set route by the user or inferred via default IPAM
// Verify ipvlan l2 mode sets the proper default gateway routes via netlink
// for either an explicitly set route by the user or inferred via default IPAM
func testIpvlanL2Addressing(t *testing.T, ctx context.Context, client dclient.APIClient) {
const parentIfName = "di-dummy0"
n.CreateMasterDummy(ctx, t, parentIfName)
defer n.DeleteInterface(ctx, t, parentIfName)

netNameL2 := "dualstackl2"
net.CreateNoError(ctx, t, client, netNameL2,
net.WithIPvlan("", "l2"),
net.WithIPvlan(parentIfName, "l2"),
net.WithIPv6(),
net.WithIPAM("172.28.140.0/24", "172.28.140.254"),
net.WithIPAM("2001:db8:abcb::/64", ""),
)
assert.Check(t, n.IsNetworkAvailable(ctx, client, netNameL2))

id1 := container.Run(ctx, t, client,
id := container.Run(ctx, t, client,
container.WithNetworkMode(netNameL2),
)
// Validate ipvlan l2 mode defaults gateway sets the default IPAM next-hop inferred from the subnet
result, err := container.Exec(ctx, client, id1, []string{"ip", "route"})
result, err := container.Exec(ctx, client, id, []string{"ip", "route"})
assert.NilError(t, err)
assert.Check(t, strings.Contains(result.Combined(), "default via 172.28.140.254 dev eth0"))
assert.Check(t, is.Contains(result.Combined(), "default via 172.28.140.254 dev eth0"))
// Validate ipvlan l2 mode sets the v6 gateway to the user specified default gateway/next-hop
result, err = container.Exec(ctx, client, id1, []string{"ip", "-6", "route"})
result, err = container.Exec(ctx, client, id, []string{"ip", "-6", "route"})
assert.NilError(t, err)
assert.Check(t, strings.Contains(result.Combined(), "default via 2001:db8:abcb::1 dev eth0"))
assert.Check(t, is.Contains(result.Combined(), "default via 2001:db8:abcb::1 dev eth0"))
}

// Validate ipvlan l3 mode sets the v4 gateway to dev eth0 and disregards any explicit or inferred next-hops
func testIpvlanL3Addressing(t *testing.T, ctx context.Context, client dclient.APIClient) {
const parentIfName = "di-dummy0"
n.CreateMasterDummy(ctx, t, parentIfName)
defer n.DeleteInterface(ctx, t, parentIfName)

// Validate ipvlan l3 mode sets the v4 gateway to dev eth0 and disregards any explicit or inferred next-hops
netNameL3 := "dualstackl3"
net.CreateNoError(ctx, t, client, netNameL3,
net.WithIPvlan("", "l3"),
net.WithIPvlan(parentIfName, "l3"),
net.WithIPv6(),
net.WithIPAM("172.28.160.0/24", "172.28.160.254"),
net.WithIPAM("2001:db8:abcd::/64", "2001:db8:abcd::254"),
)
assert.Check(t, n.IsNetworkAvailable(ctx, client, netNameL3))

id2 := container.Run(ctx, t, client,
id := container.Run(ctx, t, client,
container.WithNetworkMode(netNameL3),
)
// Validate ipvlan l3 mode sets the v4 gateway to dev eth0 and disregards any explicit or inferred next-hops
result, err = container.Exec(ctx, client, id2, []string{"ip", "route"})
result, err := container.Exec(ctx, client, id, []string{"ip", "route"})
assert.NilError(t, err)
assert.Check(t, strings.Contains(result.Combined(), "default dev eth0"))
assert.Check(t, is.Contains(result.Combined(), "default dev eth0"))
// Validate ipvlan l3 mode sets the v6 gateway to dev eth0 and disregards any explicit or inferred next-hops
result, err = container.Exec(ctx, client, id2, []string{"ip", "-6", "route"})
result, err = container.Exec(ctx, client, id, []string{"ip", "-6", "route"})
assert.NilError(t, err)
assert.Check(t, strings.Contains(result.Combined(), "default dev eth0"))
assert.Check(t, is.Contains(result.Combined(), "default dev eth0"))
}

var (
once sync.Once
ipvlanSupported bool
)
// TestIPVlanDNS checks whether DNS is forwarded, for combinations of l2/l3 mode,
// with/without a parent interface, and with '--internal'. Note that, there's no
// attempt here to give the ipvlan network external connectivity - when this test
// supplies a parent interface, it's a dummy. External DNS lookups only work
// because the daemon is configured to see a host resolver on a loopback
// interface, so the external DNS lookup happens in the host's namespace. The
// test is checking that an automatically configured dummy interface causes the
// network to behave as if it was '--internal'. Regression test for
// https://github.com/moby/moby/issues/47662
func TestIPVlanDNS(t *testing.T) {
skip.If(t, testEnv.IsRootless, "rootless mode has different view of network")

// figure out if ipvlan is supported by the kernel
func ipvlanKernelSupport(t *testing.T) bool {
once.Do(func() {
// this may have the side effect of enabling the ipvlan module
exec.Command("modprobe", "ipvlan").Run()
_, err := os.Stat("/sys/module/ipvlan")
if err == nil {
ipvlanSupported = true
} else if !os.IsNotExist(err) {
t.Logf("WARNING: ipvlanKernelSupport: stat failed: %v\n", err)
}
})
ctx := testutil.StartSpan(baseContext, t)

net.StartDaftDNS(t, "127.0.0.1")

return ipvlanSupported
tmpFileName := net.WriteTempResolvConf(t, "127.0.0.1")
d := daemon.New(t, daemon.WithEnvVars("DOCKER_TEST_RESOLV_CONF_PATH="+tmpFileName))
d.StartWithBusybox(ctx, t)
t.Cleanup(func() { d.Stop(t) })
c := d.NewClientT(t)

const parentIfName = "di-dummy0"
n.CreateMasterDummy(ctx, t, parentIfName)
defer n.DeleteInterface(ctx, t, parentIfName)

const netName = "ipvlan-dns-net"

testcases := []struct {
name string
parent string
internal bool
expDNS bool
}{
{
name: "with parent",
parent: parentIfName,
// External DNS should be used (even though the network has no external connectivity).
expDNS: true,
},
{
name: "no parent",
// External DNS should not be used, equivalent to '--internal'.
},
{
name: "with parent, internal",
parent: parentIfName,
internal: true,
// External DNS should not be used.
},
}

for _, mode := range []string{"l2", "l3"} {
for _, tc := range testcases {
name := fmt.Sprintf("Mode=%v/HasParent=%v/Internal=%v", mode, tc.parent != "", tc.internal)
t.Run(name, func(t *testing.T) {
ctx := testutil.StartSpan(ctx, t)
createOpts := []func(*types.NetworkCreate){
net.WithIPvlan(tc.parent, mode),
}
if tc.internal {
createOpts = append(createOpts, net.WithInternal())
}
net.CreateNoError(ctx, t, c, netName, createOpts...)
defer c.NetworkRemove(ctx, netName)

ctrId := container.Run(ctx, t, c, container.WithNetworkMode(netName))
defer c.ContainerRemove(ctx, ctrId, containertypes.RemoveOptions{Force: true})
res, err := container.Exec(ctx, c, ctrId, []string{"nslookup", "test.example"})
assert.NilError(t, err)
if tc.expDNS {
assert.Check(t, is.Equal(res.ExitCode, 0))
assert.Check(t, is.Contains(res.Stdout(), net.DNSRespAddr))
} else {
assert.Check(t, is.Equal(res.ExitCode, 1))
assert.Check(t, is.Contains(res.Stdout(), "SERVFAIL"))
}
})
}
}
}

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