Merge pull request #8431 from mheon/networks_returns_default

Make c.networks() list include the default network

libpod/container.go

@@ -13,6 +13,7 @@ import (
 	"github.com/containers/image/v5/manifest"
 	"github.com/containers/podman/v2/libpod/define"
 	"github.com/containers/podman/v2/libpod/lock"
+	"github.com/containers/podman/v2/pkg/rootless"
 	"github.com/containers/storage"
 	"github.com/cri-o/ocicni/pkg/ocicni"
 	spec "github.com/opencontainers/runtime-spec/specs-go"
@@ -1095,13 +1096,17 @@ func (c *Container) Umask() string {
 // values at runtime via network connect and disconnect.
 // If the container is configured to use CNI and this function returns an empty
 // array, the container will still be connected to the default network.
-func (c *Container) Networks() ([]string, error) {
+// The second return parameter, a bool, indicates that the container container
+// is joining the default CNI network - the network name will be included in the
+// returned array of network names, but the container did not explicitly join
+// this network.
+func (c *Container) Networks() ([]string, bool, error) {
 	if !c.batched {
 		c.lock.Lock()
 		defer c.lock.Unlock()
 
 		if err := c.syncContainer(); err != nil {
-			return nil, err
+			return nil, false, err
 		}
 	}
 
@@ -1109,19 +1114,22 @@ func (c *Container) Networks() ([]string, error) {
 }
 
 // Unlocked accessor for networks
-func (c *Container) networks() ([]string, error) {
+func (c *Container) networks() ([]string, bool, error) {
 	networks, err := c.runtime.state.GetNetworks(c)
 	if err != nil && errors.Cause(err) == define.ErrNoSuchNetwork {
-		return c.config.Networks, nil
+		if len(c.config.Networks) == 0 && !rootless.IsRootless() {
+			return []string{c.runtime.netPlugin.GetDefaultNetworkName()}, true, nil
+		}
+		return c.config.Networks, false, nil
 	}
 
-	return networks, err
+	return networks, false, err
 }
 
 // networksByNameIndex provides us with a map of container networks where key
 // is network name and value is the index position
 func (c *Container) networksByNameIndex() (map[string]int, error) {
-	networks, err := c.networks()
+	networks, _, err := c.networks()
 	if err != nil {
 		return nil, err
 	}

libpod/container_internal.go

@@ -641,18 +641,13 @@ func (c *Container) removeIPv4Allocations() error {
 		cniDefaultNetwork = c.runtime.netPlugin.GetDefaultNetworkName()
 	}
 
-	networks, err := c.networks()
+	networks, _, err := c.networks()
 	if err != nil {
 		return err
 	}
 
-	switch {
-	case len(networks) > 0 && len(networks) != len(c.state.NetworkStatus):
+	if len(networks) != len(c.state.NetworkStatus) {
 		return errors.Wrapf(define.ErrInternal, "network mismatch: asked to join %d CNI networks but got %d CNI results", len(networks), len(c.state.NetworkStatus))
-	case len(networks) == 0 && len(c.state.NetworkStatus) != 1:
-		return errors.Wrapf(define.ErrInternal, "network mismatch: did not specify CNI networks but joined more than one (%d)", len(c.state.NetworkStatus))
-	case len(networks) == 0 && cniDefaultNetwork == "":
-		return errors.Wrapf(define.ErrInternal, "could not retrieve name of CNI default network")
 	}
 
 	for index, result := range c.state.NetworkStatus {

libpod/networking_linux.go

@@ -110,10 +110,15 @@ func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Re
 
 	podName := getCNIPodName(ctr)
 
-	networks, err := ctr.networks()
+	networks, _, err := ctr.networks()
 	if err != nil {
 		return nil, err
 	}
+	// All networks have been removed from the container.
+	// This is effectively forcing net=none.
+	if len(networks) == 0 {
+		return nil, nil
+	}
 
 	// Update container map of interface descriptions
 	if err := ctr.setupNetworkDescriptions(networks); err != nil {
@@ -224,7 +229,7 @@ func (r *Runtime) setupRootlessNetNS(ctr *Container) error {
 	if ctr.config.NetMode.IsSlirp4netns() {
 		return r.setupSlirp4netns(ctr)
 	}
-	networks, err := ctr.networks()
+	networks, _, err := ctr.networks()
 	if err != nil {
 		return err
 	}
@@ -744,13 +749,13 @@ func (r *Runtime) teardownNetNS(ctr *Container) error {
 
 	logrus.Debugf("Tearing down network namespace at %s for container %s", ctr.state.NetNS.Path(), ctr.ID())
 
-	networks, err := ctr.networks()
+	networks, _, err := ctr.networks()
 	if err != nil {
 		return err
 	}
 
 	// rootless containers do not use the CNI plugin directly
-	if !rootless.IsRootless() && !ctr.config.NetMode.IsSlirp4netns() {
+	if !rootless.IsRootless() && !ctr.config.NetMode.IsSlirp4netns() && len(networks) > 0 {
 		var requestedIP net.IP
 		if ctr.requestedIP != nil {
 			requestedIP = ctr.requestedIP
@@ -863,7 +868,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 	settings := new(define.InspectNetworkSettings)
 	settings.Ports = makeInspectPortBindings(c.config.PortMappings)
 
-	networks, err := c.networks()
+	networks, isDefault, err := c.networks()
 	if err != nil {
 		return nil, err
 	}
@@ -872,7 +877,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 	if c.state.NetNS == nil {
 		// We still want to make dummy configurations for each CNI net
 		// the container joined.
-		if len(networks) > 0 {
+		if len(networks) > 0 && !isDefault {
 			settings.Networks = make(map[string]*define.InspectAdditionalNetwork, len(networks))
 			for _, net := range networks {
 				cniNet := new(define.InspectAdditionalNetwork)
@@ -893,7 +898,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e
 	}
 
 	// If we have CNI networks - handle that here
-	if len(networks) > 0 {
+	if len(networks) > 0 && !isDefault {
 		if len(networks) != len(c.state.NetworkStatus) {
 			return nil, errors.Wrapf(define.ErrInternal, "network inspection mismatch: asked to join %d CNI networks but have information on %d networks", len(networks), len(c.state.NetworkStatus))
 		}
@@ -1101,7 +1106,7 @@ func (c *Container) NetworkConnect(nameOrID, netName string, aliases []string) e
 		return err
 	}
 
-	ctrNetworks, err := c.networks()
+	ctrNetworks, _, err := c.networks()
 	if err != nil {
 		return err
 	}

libpod/rootless_cni_linux.go

@@ -40,7 +40,7 @@ const (
 //
 // AllocRootlessCNI does not lock c. c should be already locked.
 func AllocRootlessCNI(ctx context.Context, c *Container) (ns.NetNS, []*cnitypes.Result, error) {
-	networks, err := c.networks()
+	networks, _, err := c.networks()
 	if err != nil {
 		return nil, nil, err
 	}
@@ -81,7 +81,7 @@ func AllocRootlessCNI(ctx context.Context, c *Container) (ns.NetNS, []*cnitypes.
 //
 // DeallocRootlessCNI does not lock c. c should be already locked.
 func DeallocRootlessCNI(ctx context.Context, c *Container) error {
-	networks, err := c.networks()
+	networks, _, err := c.networks()
 	if err != nil {
 		return err
 	}