Fixing iface deletion bug when netIds don't match

The project assumes that a DanmNet's NetworkID and ObjectMeta.Name parameters always match.
This is even outlined inthe schema descriptor.
However, recently we have introduced some changes which broke this assumption.
First, with the "default" feature, and then lately with the variable static delegate configuration.
The user might not even perceive it, but as a result of these changes interfaces weren't properly cleaned-up during CNI DEL invocations.
Instead of re-writing the whole codebase, we save the real name of the network as well into the interface's DanmEp, and use this parameter when we read the network descriptor during the deletion of the interface.
Meaning of NetworkID parameter left untouched in all the other places, but eventually, we need to revise when to sue which parameter.

Commit contains one more smal,, but important change: the first interface of a Pod will be always named "eth0" from now on.
This change will make it impossible for users to accidentally screw-up network naming, and thus kill their own Pod.

crd/apis/danm/v1/types.go

@@ -79,15 +79,14 @@ type DanmEp struct {
 
 type DanmEpSpec struct {
   NetworkID   string      `json:"NetworkID"`
+  NetworkName string      `json:"NetworkName"`
   NetworkType string      `json:"NetworkType"`
   EndpointID  string      `json:"EndpointID"`
   Iface       DanmEpIface `json:"Interface"`
   Host        string      `json:"Host,omitempty"`
   Pod         string      `json:"Pod"`
   CID         string      `json:"CID,omitempty"`
   Netns       string      `json:"netns,omitempty"`
-  Creator     string      `json:"Creator,omitempty"`
-  Expires     string      `json:"Expires,omitempty"`
 }
 
 type DanmEpIface struct {

pkg/cnidel/cnidel.go

@@ -261,6 +261,10 @@ func GetEnv(key, fallback string) string {
 // If a name is explicitly set in the related DanmNet API object, the NIC will be named accordingly.
 // If a name is not explicitly set, then DANM will name the interface ethX where X=sequence number of the interface
 func CalculateIfaceName(chosenName, defaultName string, sequenceId int) string {
+  //Kubelet expects the first interface to be literally named "eth0", so...
+  if sequenceId == 0 {
+    return "eth0"
+  }
   if chosenName != "" {
     return chosenName + strconv.Itoa(sequenceId)
   }

pkg/metacni/metacni.go

@@ -296,7 +296,7 @@ func createDelegatedInterface(syncher *syncher.Syncher, danmClient danmclientset
     Proutes6:    iface.Proutes6,
     DeviceID:    iface.Device,
   }
-  ep, err := createDanmEp(epIfaceSpec, netInfo.Spec.NetworkID, netInfo.Spec.NetworkType, args)
+  ep, err := createDanmEp(epIfaceSpec, netInfo, args)
   if err != nil {
     syncher.PushResult(iface.Network, errors.New("DanmEp object could not be created due to error:" + err.Error()), nil)
     return
@@ -333,8 +333,7 @@ func createDanmInterface(syncher *syncher.Syncher, danmClient danmclientset.Inte
     Proutes: iface.Proutes,
     Proutes6: iface.Proutes6,
   }
-  networkType := "ipvlan"
-  ep, err := createDanmEp(epSpec, netId, networkType, args)
+  ep, err := createDanmEp(epSpec, netInfo, args)
   if err != nil {
     ipam.GarbageCollectIps(danmClient, netInfo, ip4, ip6)
     syncher.PushResult(iface.Network, errors.New("DanmEp object could not be created due to error:" + err.Error()), nil)
@@ -371,7 +370,7 @@ func createDanmInterface(syncher *syncher.Syncher, danmClient danmclientset.Inte
   syncher.PushResult(iface.Network, nil, danmResult)
 }
 
-func createDanmEp(epInput danmtypes.DanmEpIface, netId string, neType string, args *cniArgs) (danmtypes.DanmEp, error) {
+func createDanmEp(epInput danmtypes.DanmEpIface, netInfo *danmtypes.DanmNet, args *cniArgs) (danmtypes.DanmEp, error) {
   epidInt, err := uuid.NewV4()
   if err != nil {
     return danmtypes.DanmEp{}, errors.New("uuid.NewV4 returned error during EP creation:" + err.Error())
@@ -381,16 +380,19 @@ func createDanmEp(epInput danmtypes.DanmEpIface, netId string, neType string, ar
   if err != nil {
     return danmtypes.DanmEp{}, errors.New("OS.Hostname returned error during EP creation:" + err.Error())
   }
+  if netInfo.Spec.NetworkType == "" {
+    netInfo.Spec.NetworkType = "ipvlan" 
+  }
   epSpec := danmtypes.DanmEpSpec {
-    NetworkID: netId,
-    NetworkType: neType,
+    NetworkID: netInfo.Spec.NetworkID,
+    NetworkName: netInfo.ObjectMeta.Name,
+    NetworkType: netInfo.Spec.NetworkType,
     EndpointID: epid,
     Iface: epInput,
     Host: host,
     Pod: args.podId,
     CID: args.containerId,
     Netns: args.netns,
-    Creator: "danm",
   }
   meta := meta_v1.ObjectMeta {
     Name: epid,
@@ -476,7 +478,7 @@ func deleteInterface(args *cniArgs, syncher *syncher.Syncher, ep danmtypes.DanmE
     syncher.PushResult(ep.Spec.NetworkID, errors.New("failed to create danmClient:" + err.Error()), nil)
     return
   }
-  netInfo, err := danmClient.DanmV1().DanmNets(args.nameSpace).Get(ep.Spec.NetworkID, meta_v1.GetOptions{})
+  netInfo, err := danmClient.DanmV1().DanmNets(args.nameSpace).Get(ep.Spec.NetworkName, meta_v1.GetOptions{})
   if err != nil {
     syncher.PushResult(ep.Spec.NetworkID, errors.New("failed to get DanmNet:"+ err.Error()), nil)
     return

test/uts/cnidel_test/cnidel_test.go

@@ -257,15 +257,20 @@ func TestCalculateIfaceName(t *testing.T) {
   testDefaultName := "notthechosenone"
   testSequenceId := 4
   expChosenName := testChosenName+strconv.Itoa(testSequenceId)
-  expDefName := testDefaultName+strconv.Itoa(testSequenceId)
   ifaceName := cnidel.CalculateIfaceName(testChosenName, testDefaultName, testSequenceId)
   if ifaceName != expChosenName {
     t.Errorf("Received value for explicitly set interface name: %s does not match with expected: %s", ifaceName, testChosenName)
   }
+  expDefName := testDefaultName+strconv.Itoa(testSequenceId)
   defIfaceName := cnidel.CalculateIfaceName("", testDefaultName, testSequenceId)
   if defIfaceName != expDefName {
     t.Errorf("Received value for default interface name: %s does not match with expected: %s", defIfaceName, testChosenName)
   }
+  expFirstNicName := "eth0"
+  firstIfaceName := cnidel.CalculateIfaceName(testChosenName, testDefaultName, 0)
+  if firstIfaceName != expFirstNicName {
+    t.Errorf("The first interface shall always be named eth0, regardless what the user wants")
+  }
 }
 
 func TestDelegateInterfaceSetup(t *testing.T) {