prevent unpredictable results with network create|remove

cmd/podman/networks/create.go

@@ -7,7 +7,6 @@ import (
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/libpod/define"
 	"github.com/containers/podman/v2/pkg/domain/entities"
-	"github.com/containers/podman/v2/pkg/network"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 )
@@ -56,9 +55,6 @@ func networkCreate(cmd *cobra.Command, args []string) error {
 	var (
 		name string
 	)
-	if err := network.IsSupportedDriver(networkCreateOptions.Driver); err != nil {
-		return err
-	}
 	if len(args) > 0 {
 		if !define.NameRegex.MatchString(args[0]) {
 			return define.RegexError

cmd/podman/networks/list.go

@@ -10,8 +10,8 @@ import (
 
 	"github.com/containers/podman/v2/cmd/podman/registry"
 	"github.com/containers/podman/v2/cmd/podman/validate"
+	"github.com/containers/podman/v2/libpod/network"
 	"github.com/containers/podman/v2/pkg/domain/entities"
-	"github.com/containers/podman/v2/pkg/network"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 )

pkg/network/config.go → libpod/network/config.go

@@ -3,6 +3,8 @@ package network
 import (
 	"encoding/json"
 	"net"
+
+	"github.com/containers/storage/pkg/lockfile"
 )
 
 // TODO once the containers.conf file stuff is worked out, this should be modified
@@ -17,8 +19,17 @@ const (
 	// DefaultPodmanDomainName is used for the dnsname plugin to define
 	// a localized domain name for a created network
 	DefaultPodmanDomainName = "dns.podman"
+	// LockFileName is used for obtaining a lock and is appended
+	// to libpod's tmpdir in practice
+	LockFileName = "cni.lock"
 )
 
+// CNILock is for preventing name collision and
+// unpredictable results when doing some CNI operations.
+type CNILock struct {
+	lockfile.Locker
+}
+
 // GetDefaultPodmanNetwork outputs the default network for podman
 func GetDefaultPodmanNetwork() (*net.IPNet, error) {
 	_, n, err := net.ParseCIDR("10.88.1.0/24")

libpod/network/create.go

@@ -0,0 +1,195 @@
+package network
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/containernetworking/cni/pkg/version"
+	"github.com/containers/podman/v2/libpod"
+	"github.com/containers/podman/v2/pkg/domain/entities"
+	"github.com/containers/podman/v2/pkg/util"
+	"github.com/pkg/errors"
+)
+
+func Create(name string, options entities.NetworkCreateOptions, r *libpod.Runtime) (*entities.NetworkCreateReport, error) {
+	var fileName string
+	if err := isSupportedDriver(options.Driver); err != nil {
+		return nil, err
+	}
+	config, err := r.GetConfig()
+	if err != nil {
+		return nil, err
+	}
+	// Acquire a lock for CNI
+	l, err := acquireCNILock(filepath.Join(config.Engine.TmpDir, LockFileName))
+	if err != nil {
+		return nil, err
+	}
+	defer l.releaseCNILock()
+	if len(options.MacVLAN) > 0 {
+		fileName, err = createMacVLAN(r, name, options)
+	} else {
+		fileName, err = createBridge(r, name, options)
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &entities.NetworkCreateReport{Filename: fileName}, nil
+}
+
+// createBridge creates a CNI network
+func createBridge(r *libpod.Runtime, name string, options entities.NetworkCreateOptions) (string, error) {
+	isGateway := true
+	ipMasq := true
+	subnet := &options.Subnet
+	ipRange := options.Range
+	runtimeConfig, err := r.GetConfig()
+	if err != nil {
+		return "", err
+	}
+	// if range is provided, make sure it is "in" network
+	if subnet.IP != nil {
+		// if network is provided, does it conflict with existing CNI or live networks
+		err = ValidateUserNetworkIsAvailable(runtimeConfig, subnet)
+	} else {
+		// if no network is provided, figure out network
+		subnet, err = GetFreeNetwork(runtimeConfig)
+	}
+	if err != nil {
+		return "", err
+	}
+	gateway := options.Gateway
+	if gateway == nil {
+		// if no gateway is provided, provide it as first ip of network
+		gateway = CalcGatewayIP(subnet)
+	}
+	// if network is provided and if gateway is provided, make sure it is "in" network
+	if options.Subnet.IP != nil && options.Gateway != nil {
+		if !subnet.Contains(gateway) {
+			return "", errors.Errorf("gateway %s is not in valid for subnet %s", gateway.String(), subnet.String())
+		}
+	}
+	if options.Internal {
+		isGateway = false
+		ipMasq = false
+	}
+
+	// if a range is given, we need to ensure it is "in" the network range.
+	if options.Range.IP != nil {
+		if options.Subnet.IP == nil {
+			return "", errors.New("you must define a subnet range to define an ip-range")
+		}
+		firstIP, err := FirstIPInSubnet(&options.Range)
+		if err != nil {
+			return "", err
+		}
+		lastIP, err := LastIPInSubnet(&options.Range)
+		if err != nil {
+			return "", err
+		}
+		if !subnet.Contains(firstIP) || !subnet.Contains(lastIP) {
+			return "", errors.Errorf("the ip range %s does not fall within the subnet range %s", options.Range.String(), subnet.String())
+		}
+	}
+	bridgeDeviceName, err := GetFreeDeviceName(runtimeConfig)
+	if err != nil {
+		return "", err
+	}
+
+	if len(name) > 0 {
+		netNames, err := GetNetworkNamesFromFileSystem(runtimeConfig)
+		if err != nil {
+			return "", err
+		}
+		if util.StringInSlice(name, netNames) {
+			return "", errors.Errorf("the network name %s is already used", name)
+		}
+	} else {
+		// If no name is given, we give the name of the bridge device
+		name = bridgeDeviceName
+	}
+
+	ncList := NewNcList(name, version.Current())
+	var plugins []CNIPlugins
+	var routes []IPAMRoute
+
+	defaultRoute, err := NewIPAMDefaultRoute(IsIPv6(subnet.IP))
+	if err != nil {
+		return "", err
+	}
+	routes = append(routes, defaultRoute)
+	ipamConfig, err := NewIPAMHostLocalConf(subnet, routes, ipRange, gateway)
+	if err != nil {
+		return "", err
+	}
+
+	// TODO need to iron out the role of isDefaultGW and IPMasq
+	bridge := NewHostLocalBridge(bridgeDeviceName, isGateway, false, ipMasq, ipamConfig)
+	plugins = append(plugins, bridge)
+	plugins = append(plugins, NewPortMapPlugin())
+	plugins = append(plugins, NewFirewallPlugin())
+	// if we find the dnsname plugin, we add configuration for it
+	if HasDNSNamePlugin(runtimeConfig.Network.CNIPluginDirs) && !options.DisableDNS {
+		// Note: in the future we might like to allow for dynamic domain names
+		plugins = append(plugins, NewDNSNamePlugin(DefaultPodmanDomainName))
+	}
+	ncList["plugins"] = plugins
+	b, err := json.MarshalIndent(ncList, "", "   ")
+	if err != nil {
+		return "", err
+	}
+	if err := os.MkdirAll(GetCNIConfDir(runtimeConfig), 0755); err != nil {
+		return "", err
+	}
+	cniPathName := filepath.Join(GetCNIConfDir(runtimeConfig), fmt.Sprintf("%s.conflist", name))
+	err = ioutil.WriteFile(cniPathName, b, 0644)
+	return cniPathName, err
+}
+
+func createMacVLAN(r *libpod.Runtime, name string, options entities.NetworkCreateOptions) (string, error) {
+	var (
+		plugins []CNIPlugins
+	)
+	liveNetNames, err := GetLiveNetworkNames()
+	if err != nil {
+		return "", err
+	}
+
+	config, err := r.GetConfig()
+	if err != nil {
+		return "", err
+	}
+
+	// Make sure the host-device exists
+	if !util.StringInSlice(options.MacVLAN, liveNetNames) {
+		return "", errors.Errorf("failed to find network interface %q", options.MacVLAN)
+	}
+	if len(name) > 0 {
+		netNames, err := GetNetworkNamesFromFileSystem(config)
+		if err != nil {
+			return "", err
+		}
+		if util.StringInSlice(name, netNames) {
+			return "", errors.Errorf("the network name %s is already used", name)
+		}
+	} else {
+		name, err = GetFreeDeviceName(config)
+		if err != nil {
+			return "", err
+		}
+	}
+	ncList := NewNcList(name, version.Current())
+	macvlan := NewMacVLANPlugin(options.MacVLAN)
+	plugins = append(plugins, macvlan)
+	ncList["plugins"] = plugins
+	b, err := json.MarshalIndent(ncList, "", "   ")
+	if err != nil {
+		return "", err
+	}
+	cniPathName := filepath.Join(GetCNIConfDir(config), fmt.Sprintf("%s.conflist", name))
+	err = ioutil.WriteFile(cniPathName, b, 0644)
+	return cniPathName, err
+}

libpod/network/lock.go

@@ -0,0 +1,26 @@
+package network
+
+import (
+	"github.com/containers/storage"
+)
+
+// acquireCNILock gets a lock that should be used in create and
+// delete cases to avoid unwanted collisions in network names.
+// TODO this uses a file lock and should be converted to shared memory
+// when we have a more general shared memory lock in libpod
+func acquireCNILock(lockPath string) (*CNILock, error) {
+	l, err := storage.GetLockfile(lockPath)
+	if err != nil {
+		return nil, err
+	}
+	l.Lock()
+	cnilock := CNILock{
+		Locker: l,
+	}
+	return &cnilock, nil
+}
+
+// ReleaseCNILock unlocks the previously held lock
+func (l *CNILock) releaseCNILock() {
+	l.Unlock()
+}

pkg/network/network.go → libpod/network/network.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"net"
 	"os"
+	"path/filepath"
 
 	"github.com/containernetworking/cni/pkg/types"
 	"github.com/containernetworking/plugins/plugins/ipam/host-local/backend/allocator"
@@ -20,8 +21,8 @@ var DefaultNetworkDriver = "bridge"
 // SupportedNetworkDrivers describes the list of supported drivers
 var SupportedNetworkDrivers = []string{DefaultNetworkDriver}
 
-// IsSupportedDriver checks if the user provided driver is supported
-func IsSupportedDriver(driver string) error {
+// isSupportedDriver checks if the user provided driver is supported
+func isSupportedDriver(driver string) error {
 	if util.StringInSlice(driver, SupportedNetworkDrivers) {
 		return nil
 	}
@@ -168,6 +169,11 @@ func ValidateUserNetworkIsAvailable(config *config.Config, userNet *net.IPNet) e
 // RemoveNetwork removes a given network by name.  If the network has container associated with it, that
 // must be handled outside the context of this.
 func RemoveNetwork(config *config.Config, name string) error {
+	l, err := acquireCNILock(filepath.Join(config.Engine.TmpDir, LockFileName))
+	if err != nil {
+		return err
+	}
+	defer l.releaseCNILock()
 	cniPath, err := GetCNIConfigPathByName(config, name)
 	if err != nil {
 		return err

pkg/api/handlers/compat/networks.go

@@ -12,10 +12,10 @@ import (
 	"github.com/containernetworking/cni/libcni"
 	"github.com/containers/podman/v2/libpod"
 	"github.com/containers/podman/v2/libpod/define"
+	"github.com/containers/podman/v2/libpod/network"
 	"github.com/containers/podman/v2/pkg/api/handlers/utils"
 	"github.com/containers/podman/v2/pkg/domain/entities"
 	"github.com/containers/podman/v2/pkg/domain/infra/abi"
-	"github.com/containers/podman/v2/pkg/network"
 	"github.com/docker/docker/api/types"
 	dockerNetwork "github.com/docker/docker/api/types/network"
 	"github.com/gorilla/schema"
@@ -210,6 +210,7 @@ func ListNetworks(w http.ResponseWriter, r *http.Request) {
 		report, err := getNetworkResourceByName(name, runtime)
 		if err != nil {
 			utils.InternalServerError(w, err)
+			return
 		}
 		reports = append(reports, report)
 	}
@@ -267,9 +268,9 @@ func CreateNetwork(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 	ce := abi.ContainerEngine{Libpod: runtime}
-	_, err := ce.NetworkCreate(r.Context(), name, ncOptions)
-	if err != nil {
+	if _, err := ce.NetworkCreate(r.Context(), name, ncOptions); err != nil {
 		utils.InternalServerError(w, err)
+		return
 	}
 	report := types.NetworkCreate{
 		CheckDuplicate: networkCreate.CheckDuplicate,
@@ -307,6 +308,7 @@ func RemoveNetwork(w http.ResponseWriter, r *http.Request) {
 	}
 	if err := network.RemoveNetwork(config, name); err != nil {
 		utils.InternalServerError(w, err)
+		return
 	}
 	utils.WriteResponse(w, http.StatusNoContent, "")
 }