Accessing a Real-Time Service Through AK/SK-based Authentication

Constraints

Obtaining an AK/SK Pair

If an AK/SK pair is already available, skip this step. Find the downloaded AK/SK file, which is usually named credentials.csv.

The file contains the username, AK, and SK.

Figure 1 credential.csv

Obtaining Information About a Real-Time Service

To call an API, you will need the URL and input parameters of the real-time service. Follow these steps to obtain this information:

1. Log in to the ModelArts console. In the navigation pane, choose Model Deployment > Real-Time Services.
2. Click the name of the target service to access its details page.
3. Obtain the URL and input parameters of the service.
   The API URL is the service URL. If apis defines a path in the model configuration file, append the user-defined path to the URL, for example, {URL of the real-time service}/predictions/poetry.

   Figure 2 Obtaining the API URL and file prediction input parameters of a real-time service
   

Method 1: Use Python to Send an Inference Request

1. Download the Python SDK and configure it in the development tool. For details, see Integrating the Python SDK for API request signing.
2. Create a request body for inference.
   • File input

     # coding=utf-8
     
     import requests
     import os
     from apig_sdk import signer
     
     if __name__ == '__main__':
         # Config url, ak, sk and file path.
         url = "URL of the real-time service"
         # Hardcoded or plaintext AK/SK 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.
         ak = os.environ["HUAWEICLOUD_SDK_AK"]
         sk = os.environ["HUAWEICLOUD_SDK_SK"]
         file_path = "Local path to the inference file"
     
         # Create request, set method, url, headers and body.
         method = 'POST'
         headers = {"x-sdk-content-sha256": "UNSIGNED-PAYLOAD"}
         request = signer.HttpRequest(method, url, headers)
     
         # Create sign, set the AK/SK to sign and authenticate the request.
         sig = signer.Signer()
         sig.Key = ak
         sig.Secret = sk
         sig.Sign(request)
     
         # Send request
         files = {'images': open(file_path, 'rb')}
         resp = requests.request(request.method, request.scheme + "://" + request.host + request.uri, headers=request.headers, files=files)
     
         # Print result
         print(resp.status_code)
         print(resp.text)

     file_path is the local path to the inference file. The path can be an absolute path (for example, D:/test.png for Windows and /opt/data/test.png for Linux) or a relative path (for example, ./test.png).

     Request body format of files: files = {"Request parameter": ("Load path", File content, "File type")}. For details about parameters of files, see Table 1.

     Table 1 Parameters of files

     Parameter	Mandatory	Description
     Request parameter	Yes	Parameter name of the real-time service.
     File path	No	Path for storing the file.
     File content	Yes	Content of the file to be uploaded.
     File type	No	Type of the file to be uploaded, which can be one of the following options: txt: text/plain jpg/jpeg: image/jpeg png: image/png

   • Text input (JSON)

     The following is an example request body for reading the local inference file and performing Base64 encoding:

     # coding=utf-8
     
     import base64
     import json
     import os
     import requests
     from apig_sdk import signer
     
     if __name__ == '__main__':
         # Config url, ak, sk and file path.
         url = "URL of the real-time service"
         # Hardcoded or plaintext AK/SK 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.
         ak = os.environ["HUAWEICLOUD_SDK_AK"]
         sk = os.environ["HUAWEICLOUD_SDK_SK"]
         file_path = "Local path to the inference file"
         with open(file_path, "rb") as file:
             base64_data = base64.b64encode(file.read()).decode("utf-8")
     
         # Create request, set method, url, headers and body.
         method = 'POST'
         headers = {
             'Content-Type': 'application/json'
         }
         body = {
             'image': base64_data
         }
         request = signer.HttpRequest(method, url, headers, json.dumps(body))
     
         # Create sign, set the AK/SK to sign and authenticate the request.
         sig = signer.Signer()
         sig.Key = ak
         sig.Secret = sk
         sig.Sign(request)
     
         # Send request
         resp = requests.request(request.method, request.scheme + "://" + request.host + request.uri, headers=request.headers, data=request.body)
     
         # Print result
         print(resp.status_code)
         print(resp.text)

     The body name is determined by the input parameter of the real-time service. The parameter name must be the same as that of the input parameter of the string type. image is used as an example. The value of base64_data in body is of the string type.

Method 2: Use Java to Send an Inference Request

1. Download the Java SDK and configure it in the development tool.
2. Create a Java request body for inference.

   In the APIG Java SDK, request.setBody() can only be a string. Therefore, only text inference requests are supported. If a file is input, convert the file into text using Base64.

   • File input
     The following is an example request body (JSON) for reading the local inference file and performing Base64 encoding.

     package com.apig.sdk.demo;
     import com.cloud.apigateway.sdk.utils.Client;
     import com.cloud.apigateway.sdk.utils.Request;
     import org.apache.commons.codec.binary.Base64;
     import org.apache.http.HttpHeaders;
     import org.apache.http.client.methods.CloseableHttpResponse;
     import org.apache.http.client.methods.HttpPost;
     import org.apache.http.client.methods.HttpRequestBase;
     import org.apache.http.impl.client.HttpClients;
     import org.apache.http.util.EntityUtils;
     import java.io.FileInputStream;
     import java.io.IOException;
     import java.io.InputStream;
     public class MyAkSkTest2 {
         public static void main(String[] args) {
             String url = "URL of the real-time service";
            // Hard-coded or plaintext AK/SK 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.
             String ak = System.getenv("HUAWEICLOUD_SDK_AK");
            String sk = System.getenv("HUAWEICLOUD_SDK_SK");
             String filePath = "Local path to the inference file";
             try {
                 // Create request
                 Request request = new Request();
                 // Set the AK/SK to sign and authenticate the request.
                 request.setKey(ak);
                 request.setSecret(sk);
                 // Specify a request method, such as GET, PUT, POST, DELETE, HEAD, and PATCH.
                 request.setMethod(HttpPost.METHOD_NAME);
                 // Add header parameters
                 request.addHeader(HttpHeaders.CONTENT_TYPE, "application/json");
                 // Set a request URL in the format of https://{Endpoint}/{URI}.
                 request.setUrl(url);
                 // build your json body
                 String body = "{\"image\":\"" + getBase64FromFile(filePath) + "\"}";
                 // Special characters, such as the double quotation mark ("), contained in the body must be escaped.
                 request.setBody(body);
                 // Sign the request.
                 HttpRequestBase signedRequest = Client.sign(request);
                 // Send request.
                 CloseableHttpResponse response = HttpClients.createDefault().execute(signedRequest);
                 // Print result
                 System.out.println(response.getStatusLine().getStatusCode());
                 System.out.println(EntityUtils.toString(response.getEntity()));
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
         /**
          * Convert the file into a byte array and Base64 encode it
          * @return
          */
         private static String getBase64FromFile(String filePath) {
             // Convert the file into a byte array
             InputStream in = null;
             byte[] data = null;
             try {
                 in = new FileInputStream(filePath);
                 data = new byte[in.available()];
                 in.read(data);
                 in.close();
             } catch (IOException e) {
                 e.printStackTrace();
             }
             // Base64 encode
             return new String(Base64.encodeBase64(data));
         }
     }

     

     If using Base64 encoding, you need to add a decoding step to your model inference code to handle the request body.

   • Text input (JSON)

     // Package name of the demo.
     package com.apig.sdk.demo;
     
     import com.cloud.apigateway.sdk.utils.Client;
     import com.cloud.apigateway.sdk.utils.Request;
     import org.apache.http.HttpHeaders;
     import org.apache.http.client.methods.CloseableHttpResponse;
     import org.apache.http.client.methods.HttpPost;
     import org.apache.http.client.methods.HttpRequestBase;
     import org.apache.http.impl.client.HttpClients;
     import org.apache.http.util.EntityUtils;
     
     public class MyAkSkTest {
     
         public static void main(String[] args) {
             String url = "URL of the real-time service";
            // Hard-coded or plaintext AK/SK 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.
             String ak = System.getenv("HUAWEICLOUD_SDK_AK");
            String sk = System.getenv("HUAWEICLOUD_SDK_SK");
     
             try {
                 // Create request
                 Request request = new Request();
     
                 // Set the AK/SK to sign and authenticate the request.
                 request.setKey(ak);
                 request.setSecret(sk);
     
                 // Specify a request method, such as GET, PUT, POST, DELETE, HEAD, and PATCH.
                 request.setMethod(HttpPost.METHOD_NAME);
     
                 // Add header parameters
                 request.addHeader(HttpHeaders.CONTENT_TYPE, "application/json");
     
                 // Set a request URL in the format of https://{Endpoint}/{URI}.
                 request.setUrl(url);
     
                 // Special characters, such as the double quotation mark ("), contained in the body must be escaped.
                 String body = "{}";
                 request.setBody(body);
     
                 // Sign the request.
                 HttpRequestBase signedRequest = Client.sign(request);
     
                 // Send request.
                 CloseableHttpResponse response = HttpClients.createDefault().execute(signedRequest);
     
                 // Print result
                 System.out.println(response.getStatusLine().getStatusCode());
                 System.out.println(EntityUtils.toString(response.getEntity()));
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
     }

     body is determined by the text format. JSON is used as an example.