Make c.networks() list include the default network

This makes things a lot more clear - if we are actually joining a
CNI network, we are guaranteed to get a non-zero length list of
networks.

We do, however, need to know if the network we are joining is the
default network for inspecting containers as it determines how we
populate the response struct. To handle this, add a bool to
indicate that the network listed was the default network, and
only the default network.

Signed-off-by: Matthew Heon <mheon@redhat.com>

1 files changed, 13 insertions, 8 deletions

diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index 8dce7c9fe..7a0bebd95 100644
--- a/libpod/networking_linux.go
+++ b/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
 	}