From 5524306a7aef00aaf6b8a604e50d9bf5f7a437a7 Mon Sep 17 00:00:00 2001
From: liuzhe <zhe.liu@microsoft.com>
Date: Tue, 22 Jun 2021 16:39:40 +0800
Subject: [PATCH] change ipv4 detection method

---
 dependencies/required.txt         |  1 -
 nni/tools/nnictl/config_schema.py |  9 ---------
 ts/nni_manager/common/utils.ts    | 29 +++++++++++++----------------
 3 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/dependencies/required.txt b/dependencies/required.txt
index 917b808377..820b945b8d 100644
--- a/dependencies/required.txt
+++ b/dependencies/required.txt
@@ -1,7 +1,6 @@
 astor
 hyperopt == 0.1.2
 json_tricks
-netifaces
 psutil
 pyyaml
 requests
diff --git a/nni/tools/nnictl/config_schema.py b/nni/tools/nnictl/config_schema.py
index 65e645b560..16725a2dfc 100644
--- a/nni/tools/nnictl/config_schema.py
+++ b/nni/tools/nnictl/config_schema.py
@@ -5,7 +5,6 @@
 import logging
 import os
 
-import netifaces
 from schema import And, Optional, Or, Regex, Schema, SchemaError
 from nni.tools.package_utils import (
     create_validator_instance,
@@ -493,7 +492,6 @@ def validate_extras(self, experiment_config):
         self.validate_tuner_adivosr_assessor(experiment_config)
         self.validate_pai_trial_conifg(experiment_config)
         self.validate_kubeflow_operators(experiment_config)
-        self.validate_eth0_device(experiment_config)
         self.validate_hybrid_platforms(experiment_config)
         self.validate_frameworkcontroller_trial_config(experiment_config)
 
@@ -599,13 +597,6 @@ def validate_pai_trial_conifg(self, experiment_config):
                 print_warning(warning_information.format('outputDir'))
             self.validate_pai_config_path(experiment_config)
 
-    def validate_eth0_device(self, experiment_config):
-        '''validate whether the machine has eth0 device'''
-        if experiment_config.get('trainingServicePlatform') not in ['local'] \
-                and not experiment_config.get('nniManagerIp') \
-                and 'eth0' not in netifaces.interfaces():
-            raise SchemaError('This machine does not contain eth0 network device, please set nniManagerIp in config file!')
-
     def validate_hybrid_platforms(self, experiment_config):
         required_config_name_map = {
             'remote': 'machineList',
diff --git a/ts/nni_manager/common/utils.ts b/ts/nni_manager/common/utils.ts
index 917eb3ba52..0debf97cb6 100644
--- a/ts/nni_manager/common/utils.ts
+++ b/ts/nni_manager/common/utils.ts
@@ -8,6 +8,7 @@ import { randomBytes } from 'crypto';
 import * as cpp from 'child-process-promise';
 import * as cp from 'child_process';
 import { ChildProcess, spawn, StdioOptions } from 'child_process';
+import * as dgram from 'dgram';
 import * as fs from 'fs';
 import * as net from 'net';
 import * as os from 'os';
@@ -217,28 +218,24 @@ function cleanupUnitTest(): void {
     setExperimentStartupInfo(true, 'unittest', 8080, 'unittest', undefined, logLevel);
 }
 
-let cachedipv4Address: string = '';
+let cachedIpv4Address: string | null = null;
+
 /**
- * Get IPv4 address of current machine
+ * Get IPv4 address of current machine.
  */
 function getIPV4Address(): string {
-    if (cachedipv4Address && cachedipv4Address.length > 0) {
-        return cachedipv4Address;
+    if (cachedIpv4Address !== null) {
+        return cachedIpv4Address;
     }
 
-    const networkInterfaces = os.networkInterfaces();
-    if (networkInterfaces.eth0) {
-        for (const item of networkInterfaces.eth0) {
-            if (item.family === 'IPv4') {
-                cachedipv4Address = item.address;
-                return cachedipv4Address;
-            }
-        }
-    } else {
-        throw Error(`getIPV4Address() failed because os.networkInterfaces().eth0 is undefined. Please specify NNI manager IP in config.`);
-    }
+    // creates "udp connection" to a non-exist target, and get local address of the connection.
+    // since udp is connectionless, this does not send actual packets.
+    const socket = dgram.createSocket('udp4');
+    socket.connect(1, '192.0.2.0');
+    cachedIpv4Address = socket.address().address;
+    socket.close();
 
-    throw Error('getIPV4Address() failed because no valid IPv4 address found.')
+    return cachedIpv4Address;
 }
 
 /**