Creating an HTTP Function

Overview

HTTP functions are designed to optimize web services. You can send HTTP requests to URLs to trigger function execution. HTTP functions support APIG triggers only.

• HTTP functions do not distinguish between programming languages. The handler must be set in the bootstrap file. You can directly write the startup command, and allow access over port 8000. The bound IP address is 127.0.0.1.
• The bootstrap file is the startup file of the HTTP function. The HTTP function can only read bootstrap as the startup file name. If the file name is not bootstrap, the service cannot be started. For more information, see the bootstrap file example.
• HTTP functions support multiple programming languages.
• Functions must return a valid HTTP response.
• This section uses Java as an example. To use another runtime, simply change the runtime path. The code package path does not need to be changed. For the paths of other runtimes, see Table 1.

Prerequisites

1. You have prepared a Java JAR package.
2. You have prepared a bootstrap file as the startup file of the HTTP function.

   Example

   The content of the bootstrap file is as follows:

   /opt/function/runtime/java8/rtsp/jre/bin/java -jar -Dfile.encoding=utf-8 /opt/function/code/gsondemo-0.0.1-SNAPSHOT.jar

   

   For HTTP functions in Python, add the -u parameter in the bootstrap file to ensure that logs can be flushed to the disk. Example:

   /opt/function/runtime/python3.6/rtsp/python/bin/python3 -u $RUNTIME_CODE_ROOT/index.py

   • /opt/function/runtime/java8/rtsp/jre/bin/java: Java path.
   • /opt/function/code: path of the function code package.
   • gsondemo-0.0.1-SNAPSHOT.jar: example JAR package. The service path is /user/get.

     

   To use another runtime, change the runtime path by referring to Table 1. The code package path does not need to be changed.

   Table 1 Paths for different runtimes

   Runtime	Path
   Java 8	/opt/function/runtime/java8/rtsp/jre/bin/java
   Java 11	/opt/function/runtime/java11/rtsp/jre/bin/java
   Node.js 6	/opt/function/runtime/nodejs6.10/rtsp/nodejs/bin/node
   Node.js 8	/opt/function/runtime/nodejs8.10/rtsp/nodejs/bin/node
   Node.js 10	/opt/function/runtime/nodejs10.16/rtsp/nodejs/bin/node
   Node.js 12	/opt/function/runtime/nodejs12.13/rtsp/nodejs/bin/node
   Node.js 14	/opt/function/runtime/nodejs14.18/rtsp/nodejs/bin/node
   Node.js 16	/opt/function/runtime/nodejs16.17/rtsp/nodejs/bin/node
   Node.js 18	/opt/function/runtime/nodejs18.15/rtsp/nodejs/bin/node
   Python 2.7	/opt/function/runtime/python2.7/rtsp/python/bin/python
   Python 3.6	/opt/function/runtime/python3.6/rtsp/python/bin/python3
   Python 3.9	/opt/function/runtime/python3.9/rtsp/python/bin/python3

Procedure

1. Create a function.
   1. Create an HTTP function. For details, see Creating an Event Function. Pay special attention to the following parameters:
      • Function Type: HTTP function
      • Region: Select a region where you will deploy your code.
   2. Upload the code. For example, upload a ZIP file from OBS. After the upload is complete, click Deploy.

      Zip the JAR package and bootstrap file, and choose Upload > OBS ZIP.

      Figure 1 Uploading a ZIP file from OBS
      
2. Create a trigger.
   

   HTTP functions support APIG triggers only.

   1. On the function details page, choose Configuration > Triggers and click Create Trigger.
   2. Set the trigger information. This step uses an APIG (dedicated) trigger as an example. For more information, see Using an APIG (Dedicated) Trigger.
      

      In this example, Security Authentication is set to None. You need to select an authentication mode based on site requirements.

      • App: AppKey and AppSecret authentication. This mode is of high security and is recommended.
      • IAM: IAM authentication. This mode grants access permissions to IAM users only and is of medium security.
      • None: No authentication. This mode grants access permissions to all users.
   3. When the configuration is complete, click OK. After the trigger is created, API_test_http will be generated on the APIG console.
3. Publish the API.
   1. On the Triggers tab page, click an API name to go to the API overview page.
   2. Click Edit in the upper right corner. The Basic Information page is displayed.
      Figure 2 Editing an API
      
   3. Click Next. On the Define API Request page that is displayed, change Path to /user/get and click Finish.
      Figure 3 Defining an API request
      
   4. Click Publish API. On the displayed page, click Publish.
4. Trigger a function.
   1. Go to the FunctionGraph console, choose Functions > Function List in the navigation pane, and click the created HTTP function to go to its details page.
   2. Choose Configuration > Triggers, copy the URL, and access it using a browser.
      Figure 4 Copying the URL
      
   3. View the request result.
      Figure 5 Viewing the request result
      

Common Function Request Headers

The following table lists the default request header fields of an HTTP function.