C++ SDK使用说明

操作场景

使用C++语言调用APP认证的API时，您需要先获取SDK，参考API调用示例调用API。

前提条件

• 已获取API的调用信息，具体请参见开发准备。
• 安装openssl库。

  apt-get install libssl-dev

• 安装curl库。

  apt-get install libcurl4-openssl-dev

获取SDK

旧版界面：登录ROMA Connect实例控制台，在“服务集成 APIC > API调用”的“SDK”页签中下载SDK。

新版界面：登录ROMA Connect实例控制台，在“服务集成 APIC > 凭据管理”的“SDKs”页签中下载SDK。

解压后目录结构如下：

调用API示例

1. 在main.cpp中加入以下引用。

   #include <stdio.h>
   #include <stdlib.h>
   #include <string.h>
   #include <curl/curl.h>
   #include "signer.h"

2. 生成一个新的Signer， 输入API所授权凭据的Key和Secret，可参考获取API的调用信息获取。

   // Directly writing AK/SK in code is risky. For security, encrypt your AK/SK and store them in the configuration file or environment variables. 
   // In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, set environment variables HUAWEICLOUD_SDK_AK and HUAWEICLOUD_SDK_SK. 
   Signer signer(getenv("HUAWEICLOUD_SDK_AK"), getenv("HUAWEICLOUD_SDK_SK"));

3. 生成一个新的RequestParams，指定方法名、域名、请求uri、查询字符串和body，可参考获取API的调用信息获取。

    RequestParams* request = new RequestParams("POST", "c967a237-cd6c-470e-906f-a8655461897e.apigw.exampleRegion.com", "/app1",
           "Action=ListUsers&Version=2010-05-08", "demo");

4. 给请求添加x-stage头，内容为环境名。如果有需要，添加需要签名的其他头域。

   request->addHeader("x-stage", "RELEASE");

5. 进行签名，执行此函数会将生成的签名头加入request变量中。

   signer.createSignature(request);

6. 使用curl库访问API，查看访问结果。

   static size_t
   WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
   {
       size_t realsize = size * nmemb;
       struct MemoryStruct *mem = (struct MemoryStruct *)userp;
   
       mem->memory = (char*)realloc(mem->memory, mem->size + realsize + 1);
       if (mem->memory == NULL) {
           /* out of memory! */
           printf("not enough memory (realloc returned NULL)\n");
           return 0;
       }
   
       memcpy(&(mem->memory[mem->size]), contents, realsize);
       mem->size += realsize;
       mem->memory[mem->size] = 0;
   
       return realsize;
   }
   
   //send http request using curl library
   int perform_request(RequestParams* request)
   {
       CURL *curl;
       CURLcode res;
       struct MemoryStruct resp_header;
       resp_header.memory = (char*)malloc(1);
       resp_header.size = 0;
       struct MemoryStruct resp_body;
       resp_body.memory = (char*)malloc(1);
       resp_body.size = 0;
   
       curl_global_init(CURL_GLOBAL_ALL);
       curl = curl_easy_init();
   
       curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, request->getMethod().c_str());
       std::string url = "http://" + request->getHost() + request->getUri() + "?" + request->getQueryParams();
       curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
       struct curl_slist *chunk = NULL;
       std::set<Header>::iterator it;
       for (auto header : *request->getHeaders()) {
           std::string headerEntry = header.getKey() + ": " + header.getValue();
           printf("%s\n", headerEntry.c_str());
           chunk = curl_slist_append(chunk, headerEntry.c_str());
       }
       printf("-------------\n");
       curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
       curl_easy_setopt(curl, CURLOPT_COPYPOSTFIELDS, request->getPayload().c_str());
       curl_easy_setopt(curl, CURLOPT_NOBODY, 0L);
       curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
       curl_easy_setopt(curl, CURLOPT_HEADERDATA, (void *)&resp_header);
       curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&resp_body);
       //curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
       res = curl_easy_perform(curl);
       if (res != CURLE_OK) {
           fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
       }
       else {
           long status;
           curl_easy_getinfo(curl, CURLINFO_HTTP_CODE, &status);
           printf("status %d\n", status);
           printf(resp_header.memory);
           printf(resp_body.memory);
       }
       free(resp_header.memory);
       free(resp_body.memory);
       curl_easy_cleanup(curl);
   
       curl_global_cleanup();
   
       return 0;
   }

7. 运行make命令编译，得到可执行文件main，执行main文件，查看结果。