revert: async delete changes for azure-ipam (#2346)

* Revert "Adding CNI async delete to old API for cilium (#2302)"

This reverts commit e6bc6da.

* remove previous changes for async delete

Author: camrynl

azure-ipam/ipam.go

@@ -3,26 +3,20 @@ package main
 import (
 	"context"
 	"encoding/json"
-	"fmt"
 	"io"
 	"net"
 
 	"github.com/Azure/azure-container-networking/azure-ipam/internal/buildinfo"
 	"github.com/Azure/azure-container-networking/azure-ipam/ipconfig"
 	"github.com/Azure/azure-container-networking/cns"
 	cnscli "github.com/Azure/azure-container-networking/cns/client"
-	"github.com/Azure/azure-container-networking/cns/fsnotify"
 	cniSkel "github.com/containernetworking/cni/pkg/skel"
 	cniTypes "github.com/containernetworking/cni/pkg/types"
 	types100 "github.com/containernetworking/cni/pkg/types/100"
 	"github.com/pkg/errors"
 	"go.uber.org/zap"
 )
 
-const (
-	watcherPath = "/var/run/azure-vnet/deleteIDs"
-)
-
 // IPAMPlugin is the struct for the delegated azure-ipam plugin
 // https://www.cni.dev/docs/spec/#section-4-plugin-delegation
 type IPAMPlugin struct {
@@ -160,7 +154,6 @@ func (p *IPAMPlugin) CmdAdd(args *cniSkel.CmdArgs) error {
 
 // CmdDel handles CNI delete commands.
 func (p *IPAMPlugin) CmdDel(args *cniSkel.CmdArgs) error {
-	var connectionErr *cnscli.ConnectionFailureErr
 	p.logger.Info("DEL called", zap.Any("args", args))
 
 	// Create ip config request from args
@@ -188,28 +181,8 @@ func (p *IPAMPlugin) CmdDel(args *cniSkel.CmdArgs) error {
 			err = p.cnsClient.ReleaseIPAddress(context.TODO(), ipconfigReq)
 
 			if err != nil {
-				if errors.As(err, &connectionErr) {
-					p.logger.Info("Failed to release IP address from CNS due to connection failure, saving to watcher to delete")
-					addErr := fsnotify.AddFile(args.ContainerID, args.ContainerID, watcherPath)
-					if addErr != nil {
-						p.logger.Error("Failed to add file to watcher", zap.String("containerID", args.ContainerID), zap.Error(addErr))
-						return cniTypes.NewError(cniTypes.ErrTryAgainLater, addErr.Error(), fmt.Sprintf("failed to add file to watcher with containerID %s", args.ContainerID))
-					} else {
-						p.logger.Info("File successfully added to watcher directory")
-					}
-				} else {
-					p.logger.Error("Failed to release IP address to CNS using ReleaseIPAddress", zap.Error(err), zap.Any("request", ipconfigReq))
-					return cniTypes.NewError(ErrRequestIPConfigFromCNS, err.Error(), "failed to release IP address from CNS using ReleaseIPAddress")
-				}
-			}
-		} else if errors.As(err, &connectionErr) {
-			p.logger.Info("Failed to release IP addresses from CNS due to connection failure, saving to watcher to delete")
-			addErr := fsnotify.AddFile(args.ContainerID, args.ContainerID, watcherPath)
-			if addErr != nil {
-				p.logger.Error("Failed to add file to watcher", zap.String("containerID", args.ContainerID), zap.Error(addErr))
-				return cniTypes.NewError(cniTypes.ErrTryAgainLater, addErr.Error(), fmt.Sprintf("failed to add file to watcher with containerID %s", args.ContainerID))
-			} else {
-				p.logger.Info("File successfully added to watcher directory")
+				p.logger.Error("Failed to release IP address to CNS using ReleaseIPAddress", zap.Error(err), zap.Any("request", ipconfigReq))
+				return cniTypes.NewError(ErrRequestIPConfigFromCNS, err.Error(), "failed to release IP address from CNS using ReleaseIPAddress")
 			}
 		} else {
 			p.logger.Error("Failed to release IP addresses from CNS", zap.Error(err), zap.Any("request", req))