support advanced network configuration via cli

Rework the --network parse logic to support multiple networks with
specific network configuration settings.
--network can now be set multiple times. For bridge network mode the
following options have been added:
  - **alias=name**: Add network-scoped alias for the container.
  - **ip=IPv4**: Specify a static ipv4 address for this container.
  - **ip=IPv6**: Specify a static ipv6 address for this container.
  - **mac=MAC**: Specify a static mac address address for this container.
  - **interface_name**: Specify a name for the created network interface inside the container.

So now you can set --network bridge:ip=10.88.0.10,mac=44:33:22:11:00:99
for the default bridge network as well as for network names.
This is better than using --ip because we can set the ip per network
without any confusion which network the ip address should be assigned
to.
The --ip, --mac-address and --network-alias options are still supported
but --ip or --mac-address can only be set when only one network is set.
This limitation already existed previously.

The ability to specify a custom network interface name is new
Fixes #11534

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

4 files changed, 435 insertions, 15 deletions

diff --git a/pkg/specgen/generate/namespaces.go b/pkg/specgen/generate/namespaces.go
index 782156663..a2bc37e34 100644
--- a/pkg/specgen/generate/namespaces.go
+++ b/pkg/specgen/generate/namespaces.go
@@ -67,7 +67,7 @@ func GetDefaultNamespaceMode(nsType string, cfg *config.Config, pod *libpod.Pod)
 	case "cgroup":
 		return specgen.ParseCgroupNamespace(cfg.Containers.CgroupNS)
 	case "net":
-		ns, _, err := specgen.ParseNetworkNamespace(cfg.Containers.NetNS, cfg.Containers.RootlessNetworking == "cni")
+		ns, _, _, err := specgen.ParseNetworkFlag(nil)
 		return ns, err
 	}
 
@@ -259,6 +259,11 @@ func namespaceOptions(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.
 		if err != nil {
 			return nil, err
 		}
+
+		rtConfig, err := rt.GetConfigNoCopy()
+		if err != nil {
+			return nil, err
+		}
 		// if no network was specified use add the default
 		if len(s.Networks) == 0 {
 			// backwards config still allow the old cni networks list and convert to new format
@@ -271,15 +276,16 @@ func namespaceOptions(ctx context.Context, s *specgen.SpecGenerator, rt *libpod.
 				s.Networks = networks
 			} else {
 				// no networks given but bridge is set so use default network
-				rtConfig, err := rt.GetConfigNoCopy()
-				if err != nil {
-					return nil, err
-				}
 				s.Networks = map[string]types.PerNetworkOptions{
 					rtConfig.Network.DefaultNetwork: {},
 				}
 			}
 		}
+		// rename the "default" network to the correct default name
+		if opts, ok := s.Networks["default"]; ok {
+			s.Networks[rtConfig.Network.DefaultNetwork] = opts
+			delete(s.Networks, "default")
+		}
 		toReturn = append(toReturn, libpod.WithNetNS(portMappings, expose, postConfigureNetNS, "bridge", s.Networks))
 	}
 
diff --git a/pkg/specgen/namespaces.go b/pkg/specgen/namespaces.go
index 121e1ecf7..15a8ece17 100644
--- a/pkg/specgen/namespaces.go
+++ b/pkg/specgen/namespaces.go
@@ -2,10 +2,12 @@ package specgen
 
 import (
 	"fmt"
+	"net"
 	"os"
 	"strings"
 
 	"github.com/containers/common/pkg/cgroups"
+	"github.com/containers/podman/v3/libpod/define"
 	"github.com/containers/podman/v3/libpod/network/types"
 	"github.com/containers/podman/v3/pkg/rootless"
 	"github.com/containers/podman/v3/pkg/util"
@@ -325,21 +327,163 @@ func ParseNetworkNamespace(ns string, rootlessDefaultCNI bool) (Namespace, map[s
 	return toReturn, networks, nil
 }
 
-func ParseNetworkString(network string) (Namespace, map[string]types.PerNetworkOptions, map[string][]string, error) {
+// ParseNetworkFlag parses a network string slice into the network options
+// If the input is nil or empty it will use the default setting from containers.conf
+func ParseNetworkFlag(networks []string) (Namespace, map[string]types.PerNetworkOptions, map[string][]string, error) {
 	var networkOptions map[string][]string
-	parts := strings.SplitN(network, ":", 2)
+	// by default we try to use the containers.conf setting
+	// if we get at least one value use this instead
+	ns := containerConfig.Containers.NetNS
+	if len(networks) > 0 {
+		ns = networks[0]
+	}
 
-	ns, nets, err := ParseNetworkNamespace(network, containerConfig.Containers.RootlessNetworking == "cni")
-	if err != nil {
-		return Namespace{}, nil, nil, err
+	toReturn := Namespace{}
+	podmanNetworks := make(map[string]types.PerNetworkOptions)
+
+	switch {
+	case ns == string(Slirp), strings.HasPrefix(ns, string(Slirp)+":"):
+		parts := strings.SplitN(ns, ":", 2)
+		if len(parts) > 1 {
+			networkOptions = make(map[string][]string)
+			networkOptions[parts[0]] = strings.Split(parts[1], ",")
+		}
+		toReturn.NSMode = Slirp
+	case ns == string(FromPod):
+		toReturn.NSMode = FromPod
+	case ns == "" || ns == string(Default) || ns == string(Private):
+		// Net defaults to Slirp on rootless
+		if rootless.IsRootless() && containerConfig.Containers.RootlessNetworking != "cni" {
+			toReturn.NSMode = Slirp
+			break
+		}
+		// if not slirp we use bridge
+		fallthrough
+	case ns == string(Bridge), strings.HasPrefix(ns, string(Bridge)+":"):
+		toReturn.NSMode = Bridge
+		parts := strings.SplitN(ns, ":", 2)
+		netOpts := types.PerNetworkOptions{}
+		if len(parts) > 1 {
+			var err error
+			netOpts, err = parseBridgeNetworkOptions(parts[1])
+			if err != nil {
+				return toReturn, nil, nil, err
+			}
+		}
+		// we have to set the special default network name here
+		podmanNetworks["default"] = netOpts
+
+	case ns == string(NoNetwork):
+		toReturn.NSMode = NoNetwork
+	case ns == string(Host):
+		toReturn.NSMode = Host
+	case strings.HasPrefix(ns, "ns:"):
+		split := strings.SplitN(ns, ":", 2)
+		if len(split) != 2 {
+			return toReturn, nil, nil, errors.Errorf("must provide a path to a namespace when specifying ns:")
+		}
+		toReturn.NSMode = Path
+		toReturn.Value = split[1]
+	case strings.HasPrefix(ns, string(FromContainer)+":"):
+		split := strings.SplitN(ns, ":", 2)
+		if len(split) != 2 {
+			return toReturn, nil, nil, errors.Errorf("must provide name or ID or a container when specifying container:")
+		}
+		toReturn.NSMode = FromContainer
+		toReturn.Value = split[1]
+	default:
+		// we should have a normal network
+		parts := strings.SplitN(ns, ":", 2)
+		if len(parts) == 1 {
+			// Assume we have been given a comma separated list of networks for backwards compat.
+			networkList := strings.Split(ns, ",")
+			for _, net := range networkList {
+				podmanNetworks[net] = types.PerNetworkOptions{}
+			}
+		} else {
+			if parts[0] == "" {
+				return toReturn, nil, nil, errors.New("network name cannot be empty")
+			}
+			netOpts, err := parseBridgeNetworkOptions(parts[1])
+			if err != nil {
+				return toReturn, nil, nil, errors.Wrapf(err, "invalid option for network %s", parts[0])
+			}
+			podmanNetworks[parts[0]] = netOpts
+		}
+
+		// networks need bridge mode
+		toReturn.NSMode = Bridge
 	}
 
-	if len(parts) > 1 {
-		networkOptions = make(map[string][]string)
-		networkOptions[parts[0]] = strings.Split(parts[1], ",")
-		nets = nil
+	if len(networks) > 1 {
+		if !toReturn.IsBridge() {
+			return toReturn, nil, nil, errors.Wrapf(define.ErrInvalidArg, "cannot set multiple networks without bridge network mode, selected mode %s", toReturn.NSMode)
+		}
+
+		for _, network := range networks[1:] {
+			parts := strings.SplitN(network, ":", 2)
+			if parts[0] == "" {
+				return toReturn, nil, nil, errors.Wrapf(define.ErrInvalidArg, "network name cannot be empty")
+			}
+			if util.StringInSlice(parts[0], []string{string(Bridge), string(Slirp), string(FromPod), string(NoNetwork),
+				string(Default), string(Private), string(Path), string(FromContainer), string(Host)}) {
+				return toReturn, nil, nil, errors.Wrapf(define.ErrInvalidArg, "can only set extra network names, selected mode %s conflicts with bridge", parts[0])
+			}
+			netOpts := types.PerNetworkOptions{}
+			if len(parts) > 1 {
+				var err error
+				netOpts, err = parseBridgeNetworkOptions(parts[1])
+				if err != nil {
+					return toReturn, nil, nil, errors.Wrapf(err, "invalid option for network %s", parts[0])
+				}
+			}
+			podmanNetworks[parts[0]] = netOpts
+		}
+	}
+
+	return toReturn, podmanNetworks, networkOptions, nil
+}
+
+func parseBridgeNetworkOptions(opts string) (types.PerNetworkOptions, error) {
+	netOpts := types.PerNetworkOptions{}
+	if len(opts) == 0 {
+		return netOpts, nil
+	}
+	allopts := strings.Split(opts, ",")
+	for _, opt := range allopts {
+		split := strings.SplitN(opt, "=", 2)
+		switch split[0] {
+		case "ip", "ip6":
+			ip := net.ParseIP(split[1])
+			if ip == nil {
+				return netOpts, errors.Errorf("invalid ip address %q", split[1])
+			}
+			netOpts.StaticIPs = append(netOpts.StaticIPs, ip)
+
+		case "mac":
+			mac, err := net.ParseMAC(split[1])
+			if err != nil {
+				return netOpts, err
+			}
+			netOpts.StaticMAC = types.HardwareAddr(mac)
+
+		case "alias":
+			if split[1] == "" {
+				return netOpts, errors.New("alias cannot be empty")
+			}
+			netOpts.Aliases = append(netOpts.Aliases, split[1])
+
+		case "interface_name":
+			if split[1] == "" {
+				return netOpts, errors.New("interface_name cannot be empty")
+			}
+			netOpts.InterfaceName = split[1]
+
+		default:
+			return netOpts, errors.Errorf("unknown bridge network option: %s", split[0])
+		}
 	}
-	return ns, nets, networkOptions, nil
+	return netOpts, nil
 }
 
 func SetupUserNS(idmappings *storage.IDMappingOptions, userns Namespace, g *generate.Generator) (string, error) {
diff --git a/pkg/specgen/namespaces_test.go b/pkg/specgen/namespaces_test.go
new file mode 100644
index 000000000..4f69e6b98
--- /dev/null
+++ b/pkg/specgen/namespaces_test.go
@@ -0,0 +1,265 @@
+package specgen
+
+import (
+	"net"
+	"testing"
+
+	"github.com/containers/podman/v3/libpod/network/types"
+	"github.com/containers/podman/v3/pkg/rootless"
+	"github.com/stretchr/testify/assert"
+)
+
+func parsMacNoErr(mac string) types.HardwareAddr {
+	m, _ := net.ParseMAC(mac)
+	return types.HardwareAddr(m)
+}
+
+func TestParseNetworkFlag(t *testing.T) {
+	// root and rootless have different defaults
+	defaultNetName := "default"
+	defaultNetworks := map[string]types.PerNetworkOptions{
+		defaultNetName: {},
+	}
+	defaultNsMode := Namespace{NSMode: Bridge}
+	if rootless.IsRootless() {
+		defaultNsMode = Namespace{NSMode: Slirp}
+		defaultNetworks = map[string]types.PerNetworkOptions{}
+	}
+
+	tests := []struct {
+		name     string
+		args     []string
+		nsmode   Namespace
+		networks map[string]types.PerNetworkOptions
+		options  map[string][]string
+		err      string
+	}{
+		{
+			name:     "empty input",
+			args:     nil,
+			nsmode:   defaultNsMode,
+			networks: defaultNetworks,
+		},
+		{
+			name:     "empty string as input",
+			args:     []string{},
+			nsmode:   defaultNsMode,
+			networks: defaultNetworks,
+		},
+		{
+			name:     "default mode",
+			args:     []string{"default"},
+			nsmode:   defaultNsMode,
+			networks: defaultNetworks,
+		},
+		{
+			name:     "private mode",
+			args:     []string{"private"},
+			nsmode:   defaultNsMode,
+			networks: defaultNetworks,
+		},
+		{
+			name:   "bridge mode",
+			args:   []string{"bridge"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {},
+			},
+		},
+		{
+			name:     "slirp4netns mode",
+			args:     []string{"slirp4netns"},
+			nsmode:   Namespace{NSMode: Slirp},
+			networks: map[string]types.PerNetworkOptions{},
+		},
+		{
+			name:     "from pod mode",
+			args:     []string{"pod"},
+			nsmode:   Namespace{NSMode: FromPod},
+			networks: map[string]types.PerNetworkOptions{},
+		},
+		{
+			name:     "no network mode",
+			args:     []string{"none"},
+			nsmode:   Namespace{NSMode: NoNetwork},
+			networks: map[string]types.PerNetworkOptions{},
+		},
+		{
+			name:     "container mode",
+			args:     []string{"container:abc"},
+			nsmode:   Namespace{NSMode: FromContainer, Value: "abc"},
+			networks: map[string]types.PerNetworkOptions{},
+		},
+		{
+			name:     "ns path mode",
+			args:     []string{"ns:/path"},
+			nsmode:   Namespace{NSMode: Path, Value: "/path"},
+			networks: map[string]types.PerNetworkOptions{},
+		},
+		{
+			name:     "slirp4netns mode with options",
+			args:     []string{"slirp4netns:cidr=10.0.0.0/24"},
+			nsmode:   Namespace{NSMode: Slirp},
+			networks: map[string]types.PerNetworkOptions{},
+			options: map[string][]string{
+				"slirp4netns": {"cidr=10.0.0.0/24"},
+			},
+		},
+		{
+			name:   "bridge mode with options 1",
+			args:   []string{"bridge:ip=10.0.0.1,mac=11:22:33:44:55:66"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {
+					StaticIPs: []net.IP{net.ParseIP("10.0.0.1")},
+					StaticMAC: parsMacNoErr("11:22:33:44:55:66"),
+				},
+			},
+		},
+		{
+			name:   "bridge mode with options 2",
+			args:   []string{"bridge:ip=10.0.0.1,ip=10.0.0.5"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {
+					StaticIPs: []net.IP{net.ParseIP("10.0.0.1"), net.ParseIP("10.0.0.5")},
+				},
+			},
+		},
+		{
+			name:   "bridge mode with ip6 option",
+			args:   []string{"bridge:ip6=fd10::"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {
+					StaticIPs: []net.IP{net.ParseIP("fd10::")},
+				},
+			},
+		},
+		{
+			name:   "bridge mode with alias option",
+			args:   []string{"bridge:alias=myname,alias=myname2"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {
+					Aliases: []string{"myname", "myname2"},
+				},
+			},
+		},
+		{
+			name:   "bridge mode with alias option",
+			args:   []string{"bridge:alias=myname,alias=myname2"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {
+					Aliases: []string{"myname", "myname2"},
+				},
+			},
+		},
+		{
+			name:   "bridge mode with interface option",
+			args:   []string{"bridge:interface_name=eth123"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {
+					InterfaceName: "eth123",
+				},
+			},
+		},
+		{
+			name:   "bridge mode with invalid option",
+			args:   []string{"bridge:abc=123"},
+			nsmode: Namespace{NSMode: Bridge},
+			err:    "unknown bridge network option: abc",
+		},
+		{
+			name:   "bridge mode with invalid ip",
+			args:   []string{"bridge:ip=10..1"},
+			nsmode: Namespace{NSMode: Bridge},
+			err:    "invalid ip address \"10..1\"",
+		},
+		{
+			name:   "bridge mode with invalid mac",
+			args:   []string{"bridge:mac=123"},
+			nsmode: Namespace{NSMode: Bridge},
+			err:    "address 123: invalid MAC address",
+		},
+		{
+			name:   "network name",
+			args:   []string{"someName"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				"someName": {},
+			},
+		},
+		{
+			name:   "network name with options",
+			args:   []string{"someName:ip=10.0.0.1"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				"someName": {StaticIPs: []net.IP{net.ParseIP("10.0.0.1")}},
+			},
+		},
+		{
+			name:   "multiple networks",
+			args:   []string{"someName", "net2"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				"someName": {},
+				"net2":     {},
+			},
+		},
+		{
+			name:   "multiple networks with options",
+			args:   []string{"someName:ip=10.0.0.1", "net2:ip=10.10.0.1"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				"someName": {StaticIPs: []net.IP{net.ParseIP("10.0.0.1")}},
+				"net2":     {StaticIPs: []net.IP{net.ParseIP("10.10.0.1")}},
+			},
+		},
+		{
+			name:   "multiple networks with bridge mode first should map to default net",
+			args:   []string{"bridge", "net2"},
+			nsmode: Namespace{NSMode: Bridge},
+			networks: map[string]types.PerNetworkOptions{
+				defaultNetName: {},
+				"net2":         {},
+			},
+		},
+		{
+			name:   "conflicting network modes should error",
+			args:   []string{"bridge", "host"},
+			nsmode: Namespace{NSMode: Bridge},
+			err:    "can only set extra network names, selected mode host conflicts with bridge: invalid argument",
+		},
+		{
+			name:   "multiple networks empty name should error",
+			args:   []string{"someName", ""},
+			nsmode: Namespace{NSMode: Bridge},
+			err:    "network name cannot be empty: invalid argument",
+		},
+		{
+			name:   "multiple networks on invalid mode should error",
+			args:   []string{"host", "net2"},
+			nsmode: Namespace{NSMode: Host},
+			err:    "cannot set multiple networks without bridge network mode, selected mode host: invalid argument",
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			got, got1, got2, err := ParseNetworkFlag(tt.args)
+			if tt.err != "" {
+				assert.EqualError(t, err, tt.err, tt.name)
+			} else {
+				assert.NoError(t, err, tt.name)
+			}
+
+			assert.Equal(t, tt.nsmode, got, tt.name)
+			assert.Equal(t, tt.networks, got1, tt.name)
+			assert.Equal(t, tt.options, got2, tt.name)
+		})
+	}
+}
diff --git a/pkg/specgen/pod_validate.go b/pkg/specgen/pod_validate.go
index 32c1159c6..224a5b12d 100644
--- a/pkg/specgen/pod_validate.go
+++ b/pkg/specgen/pod_validate.go
@@ -42,6 +42,11 @@ func (p *PodSpecGenerator) Validate() error {
 		if p.NetNS.NSMode != Default && p.NetNS.NSMode != "" {
 			return errors.New("NoInfra and network modes cannot be used together")
 		}
+		// Note that networks might be set when --ip or --mac was set
+		// so we need to check that no networks are set without the infra
+		if len(p.Networks) > 0 {
+			return errors.New("cannot set networks options without infra container")
+		}
 		if len(p.DNSOption) > 0 {
 			return exclusivePodOptions("NoInfra", "DNSOption")
 		}