HTTPDNS:Best practices for using HTTPDNS with the Alibaba Cloud OSS SDK for iOS

2.1 Install the HTTPDNS proxy

Add the EMASLocalProxy dependency to the Podfile:

source 'https://github.com/aliyun/aliyun-specs.git'

target 'yourAppTarget' do
    use_framework!
    
    pod 'AlicloudHTTPDNS', 'x.x.x'
    pod 'AliyunOSSiOS', 'x.x.x'
    pod 'EMASLocalProxy', 'x.x.x'
end

Version requirements:

• AlicloudHTTPDNS: >= 3.0.0

• AliyunOSSiOS: >= 2.11.2

• EMASLocalProxy: >= 1.4.0

For more information about integrating HTTPDNS using a local proxy, see Local proxy solution.

2.1 HTTPDNS SDK initialization

// AppDelegate.m
#import <AlicloudHttpDNS/AlicloudHttpDNS.h>

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Initialize HTTPDNS.
    HttpDnsService *httpdns = [[HttpDnsService alloc] initWithAccountID:@"your-account-id"
                                                              secretKey:@"your-secret-key"];
    [httpdns setLogEnabled:YES];
    [httpdns setHTTPSRequestEnabled:YES];
    [httpdns setPersistentCacheIPEnabled:YES];
    [httpdns setNetworkingTimeoutInterval:5];

    NSLog(@"HTTPDNS SDK initialization complete!");
    return YES;
}

2.2 Configure the OSS client

The OSS iOS SDK is available in Objective-C and Swift (V2) versions. Although the APIs are not identical, the principle for integrating HTTPDNS is the same for both versions. This topic uses the Objective-C version as an example.

#import <AliyunOSSiOS/AliyunOSSiOS.h>
#import <AlicloudHttpDNS/AlicloudHttpDNS.h>
#import "EMASLocalHttpProxy.h"

// 1. Configure the DNS resolver.
[EMASLocalHttpProxy setDNSResolverBlock:^NSArray<NSString *> * _Nullable(NSString * _Nonnull hostname) {
    HttpDnsService *httpdns = [HttpDnsService sharedInstance];
    HttpdnsResult *result = [httpdns resolveHostSync:hostname byIpType:HttpdnsQueryIPTypeBoth];

    if (result && (result.hasIpv4Address || result.hasIpv6Address)) {
        NSMutableArray<NSString *> *allIPs = [NSMutableArray array];
        if (result.hasIpv4Address) [allIPs addObjectsFromArray:result.ips];
        if (result.hasIpv6Address) [allIPs addObjectsFromArray:result.ipv6s];
        return allIPs;
    }

    return nil; // If HTTPDNS resolution fails, return nil to fall back to the system DNS.
}];


// 2. Start the proxy service and get the port.
UInt16 proxyPort = 0;
if ([EMASLocalHttpProxy isProxyReady]) {
    proxyPort = [EMASLocalHttpProxy proxyPort];
}

// 3. Create the OSS client configuration.
id<OSSCredentialProvider> credentialProvider = [[OSSPlainTextAKSKPairCredentialProvider alloc]
    initWithPlainTextAccessKey:@"your-access-key-id"      // Replace with your actual AccessKey ID.
    secretKey:@"your-access-key-secret"];                 // Replace with your actual AccessKey secret.

OSSClientConfiguration *config = [OSSClientConfiguration new];
NSString *endpoint = @"https://oss-cn-hangzhou.aliyuncs.com";

// 4. Configure the HTTPDNS proxy.
if (proxyPort > 0) {
    config.proxyHost = @"127.0.0.1";
    config.proxyPort = @(proxyPort);
}

// 5. Create the OSS client.
OSSClient *client = [[OSSClient alloc] initWithEndpoint:endpoint
                                      credentialProvider:credentialProvider
                                       clientConfiguration:config];