Add debug mode for containerd agent and minor patches (#4059)

* Add GetInterfaceNamesToNetNSMapping method in netlib

* Add GetInterfaceByIndex method in netlib

* Add debug mode for containerd platform

* Fix DNS config for debug mode

* Add firecracker debug platform in netlib

ecs-agent/netlib/model/tasknetworkconfig/network_namespace.go

@@ -87,3 +87,14 @@ func (ns *NetworkNamespace) GetPrimaryInterface() *networkinterface.NetworkInter
 func (ns *NetworkNamespace) IsPrimary() bool {
 	return ns.Index == 0
 }
+
+// GetInterfaceByIndex returns the interface in the netns that has the specified index.
+func (ns *NetworkNamespace) GetInterfaceByIndex(idx int64) *networkinterface.NetworkInterface {
+	for _, iface := range ns.NetworkInterfaces {
+		if iface.Index == idx {
+			return iface
+		}
+	}
+
+	return nil
+}

ecs-agent/netlib/model/tasknetworkconfig/task_network_config.go

@@ -73,3 +73,17 @@ func (tnc *TaskNetworkConfig) GetEniNamesToAssociationProtocolMapping() map[stri
 	}
 	return eniNameToAssociationProtocol
 }
+
+// GetInterfaceNamesToNetNSMapping returns a map where key is interface name and value is the netns
+// in which the interface exists.
+func (tnc *TaskNetworkConfig) GetInterfaceNamesToNetNSMapping() map[string]*NetworkNamespace {
+	name2NetNS := make(map[string]*NetworkNamespace)
+	for _, netNS := range tnc.NetworkNamespaces {
+		for _, iface := range netNS.NetworkInterfaces {
+			if iface.Name != "" {
+				name2NetNS[iface.Name] = netNS
+			}
+		}
+	}
+	return name2NetNS
+}

ecs-agent/netlib/model/tasknetworkconfig/task_network_config_test.go

@@ -18,8 +18,12 @@ package tasknetworkconfig
 
 import (
 	"github.com/aws/amazon-ecs-agent/ecs-agent/api/ecs/model/ecs"
+	ni "github.com/aws/amazon-ecs-agent/ecs-agent/netlib/model/networkinterface"
+
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
+	"fmt"
 	"testing"
 )
 
@@ -79,3 +83,29 @@ func TestNewTaskNetConfig(t *testing.T) {
 	assert.Equal(t, *netNSs[0], *taskNetConfig.NetworkNamespaces[0])
 	assert.Equal(t, *netNSs[1], *taskNetConfig.NetworkNamespaces[1])
 }
+
+// TestTaskNetworkConfig_GetInterfaceNamesToNetNSMapping verifies the map created
+// between interface name and netNS is accurate.
+func TestTaskNetworkConfig_GetInterfaceNamesToNetNSMapping(t *testing.T) {
+	var netNSs []*NetworkNamespace
+	for i := 0; i < 3; i++ {
+		netNSs = append(netNSs, &NetworkNamespace{
+			Name: fmt.Sprintf("ns%d", i),
+			NetworkInterfaces: []*ni.NetworkInterface{
+				{
+					Name: fmt.Sprintf("ni%d", i),
+				},
+			},
+		})
+	}
+
+	netConfig := &TaskNetworkConfig{
+		NetworkNamespaces: netNSs,
+	}
+
+	name2NetNS := netConfig.GetInterfaceNamesToNetNSMapping()
+	require.Equal(t, 3, len(name2NetNS))
+	for i := 0; i < 3; i++ {
+		require.Equal(t, name2NetNS[fmt.Sprintf("ni%d", i)].Name, fmt.Sprintf("ns%d", i))
+	}
+}

ecs-agent/netlib/platform/common_linux.go

@@ -113,6 +113,18 @@ func NewPlatform(
 		return &firecraker{
 			common: commonPlatform,
 		}, nil
+	case WarmpoolDebugPlatform:
+		return &containerdDebug{
+			containerd: containerd{
+				common: commonPlatform,
+			},
+		}, nil
+	case FirecrackerDebugPlatform:
+		return &firecrackerDebug{
+			firecraker: firecraker{
+				common: commonPlatform,
+			},
+		}, nil
 	}
 	return nil, errors.New("invalid platform: " + platformString)
 }
@@ -494,7 +506,7 @@ func (c *common) generateNetworkConfigFilesForDebugPlatforms(
 	return nil
 }
 
-func (c *common) copyFile(src, dst string, fileMode os.FileMode) error {
+func (c *common) copyFile(dst, src string, fileMode os.FileMode) error {
 	contents, err := c.ioutil.ReadFile(src)
 	if err != nil {
 		return errors.Wrapf(err, "unable to read %s", src)

ecs-agent/netlib/platform/containerd_debug_linux.go

@@ -0,0 +1,14 @@
+package platform
+
+import (
+	"github.com/aws/amazon-ecs-agent/ecs-agent/netlib/model/tasknetworkconfig"
+)
+
+// containerdDebug implements platform API methods for non-firecrakcer infrastructure.
+type containerdDebug struct {
+	containerd
+}
+
+func (c *containerdDebug) CreateDNSConfig(taskID string, netNS *tasknetworkconfig.NetworkNamespace) error {
+	return c.common.createDNSConfig(taskID, true, netNS)
+}

ecs-agent/netlib/platform/firecracker_debug_linux.go

@@ -0,0 +1,11 @@
+package platform
+
+import "github.com/aws/amazon-ecs-agent/ecs-agent/netlib/model/tasknetworkconfig"
+
+type firecrackerDebug struct {
+	firecraker
+}
+
+func (fc *firecrackerDebug) CreateDNSConfig(taskID string, netNS *tasknetworkconfig.NetworkNamespace) error {
+	return fc.common.createDNSConfig(taskID, true, netNS)
+}