PHP runtime environment

Log printing

Function Compute provides a built-in logger module, which can be used by using$GLOBALS['fcLogger']. The logs that are printed are collected to the Logstore that you specify when you create the service.

• Log level

  You can call the setLevel method to specify the level of logs that you want to print. The following table lists the log levels by severity from high to low.

  Log level	Level	Operation	Description
  EMERGENCY	600	$logger->emergency	Emergency logs
  ALERT	550	$logger->alert	Alert logs
  CRITICAL	500	$logger->critical	Critical warnings
  ERROR	400	$logger->error	Error messages
  WARNING	300	$logger->warning	Warnings
  NOTICE	250	$logger->notice	Notifications and general logs
  INFO (default severity level)	200	$logger->info	Detailed information
  DEBUG	100	$logger->debug	Debugging logs

  For more information about function logs, see Grant an event source permissions to access Function Compute.

• Example 1

  <?php
  function handler($event, $context) {
      $logger = $GLOBALS['fcLogger'];
      $logger->info("hello world");
      return 'hello world';
  };           

  After the preceding code is executed, the following log is printed:

  message:2017-07-05T05:13:35.920Z a72df088-f738-cee3-e0fe-323ad89118e5 [INFO] hello world            

• Example 2

  <?php
  use Monolog\Logger;
  function handler($evt, $ctx) {
      $logger = $GLOBALS['fcLogger'];
      $logger->setLevel(400);
      $logger->error("console error 1");
      $logger->info("console info 1");
      $logger->warning("console warn 1");
      $logger->debug("console debug 1");
  
      $logger->setLevel(Logger::WARNING);
      $logger->error("console error 2");
      $logger->info("console info 2");
      $logger->warn("console warn 2");
      $logger->debug("console debug 2");
  
      $logger->setLevel(200);
  }            

  After the preceding code is executed, the following log is printed:

  2018-08-22T09:01:26Z c19b2706-9c4d-270b-52c8-5248ed5e2315 [ERROR]: console error 1
  2018-08-22T09:01:26Z c19b2706-9c4d-270b-52c8-5248ed5e2315 [ERROR]: console error 2
  2018-08-22T09:01:26Z c19b2706-9c4d-270b-52c8-5248ed5e2315 [WARNING]: console warn 2            

Troubleshooting

Function Compute captures exceptions that occur during the execution of PHP functions and returns information about the exceptions. In the following sample code, information about the oops exception is returned.

<?php
function handler($event, $context) {
  throw new Exception("oops");
}           

The system outputs the following response when the function is called:

{
    "errorMessage":"oops",
    "errorType":"Exception",
    "stackTrace":{
        "file":"/code/index.php",
        "line":3,
        "traceString":"#0 /var/fc/runtime/php7/src/invoke.php(67): handler('{\n "product"...', Array)
#1 "
    }
}           

When an error occurs, the HTTP header in the response contains X-Fc-Error-Type: UnhandledInvocationError. For more information about error types in Function Compute, see Troubleshooting.

PHP built-in extensions

This section describes a list of built-in extensions for the PHP runtime environment and provides examples.

Built-in extension list

Example of built-in extensions

The following sample code uses imagick to process an image:

<?php
function imageProc($event, $context) {
    $image = new Imagick(__DIR__ . '/lena.jpg');
    $image->thumbnailImage(100, 0);
    $image->writeImages(__DIR__ . "/thumb.jpg", true);
    return strval($image->getImageWidth()) . "," . strval($image->getImageHeight());
}           

PHP custom extensions

You can create a directory named extension in the same directory as the function handler files, and put the .ini and .so files of the extension in the extension directory to add the PHP custom extension. The following example shows the custom extension hello. Assume that the extension has a hello_world function.

.
|____extension
| |____hello.ini
| |____hello.so
|____main.php           

• hello.ini

  extension=/code/extension/hello.so            

• main.php

      <?php
      function handler($event, $context) {
          var_dump(extension_loaded('hello'));
          hello_world(); 
          return "ok";
      }                    

PHP built-in packages

Function Compute provides the following built-in packages.

Example of built-in packages

The following sample code shows how to use methods in the OSS built-in package to upload a .txt file:

<?php
use OSS\OssClient;
function handler($event, $context) {
     $accessKeyId = $context["credentials"]["accessKeyId"];
     $accessKeySecret = $context["credentials"]["accessKeySecret"];
     $securityToken = $context["credentials"]["securityToken"];
     $endpoint = "oss-cn-shenzhen.aliyuncs.com";
     $ossClient = new OssClient($accessKeyId, $accessKeySecret, $endpoint, false, $securityToken);
     $bucket = "my-bucket";
     $object = "php.txt";
     $content = "Hello fc!";
     try {
        $ossClient->putObject($bucket, $object, $content);
     } catch (OssException $e) {
        print($e->getMessage());
     }
    return 'success';
}           

PHP custom packages

Install custom packages

Function Compute allows you to install custom packages. This section describes two methods to install custom packages.

• Method 1: Use Composer to install custom packages (recommended)

  If the package you want to use is from Packagist, the PHP Package Repository, you can use Composer to install the package. The following example shows how to install the Humble HTTP request library package requests.

  1. Create a folder to store the code and dependent modules.

     mkdir /tmp/code       

  2. Create a code file, such as /tmp/code/index.php, and use requests in the code.

     <?php
     require_once __DIR__ . "/vendor/autoload.php";
     function handler($event, $context){
        $headers = array('Accept' => 'application/json');
        $options = array('auth' => array('user', 'pass'));
        $request = Requests::get('https://www.baidu.com', $headers, $options);
        var_dump($request->status_code);
        // int(200)
        var_dump($request->headers['content-type']);
        // string(31) "application/json; charset=utf-8"
        var_dump($request->body);
        // string(26891) "[...]"
     }            

  3. Install the custom package in the /tmp/code directory.
     1. Create a file named composer.json.

        {
            "require": {
                "rmccue/requests": ">=1.0"
            }
        }           

     2. Run the composer install --no-dev command to install dependencies.

        cd /tmp/code
        composer install --no-dev            

• Method 2: Directly download the custom package
  If the package you want to use, such as Aliyun-openapi-php-sdk or Log Service SDK for PHP, is unavailable at Packagist The PHP Package Repository, you can directly download the package and reference the package in the code. The following example shows how to add a custom package of Log Service SDK for PHP:

  1. Create a folder to store the code and dependent modules.

     mkdir /tmp/code            

  2. Create a code file, such as /tmp/code/index.php, and use requests in the code.

     <?php
     /* Use the autoloader class to automatically load all required PHP modules. Make sure to use the valid path to specify the file containing the autoloader class. */
     require_once realpath(dirname(__FILE__) . '/aliyun-log-php-sdk/Log_Autoload.php');
     function handler($event, $context){
        $endpoint = 'cn-hangzhou.sls.aliyuncs.com'; // Select an endpoint that matches the region of the project created in the preceding process.
        $accessKeyId = 'your_access_key_id';        // Use the AccessKey ID of your Alibaba Cloud account.
        $accessKey = 'your_access_key';             // Use the AccessKey secret of your Alibaba Cloud account.
        $project = 'your_project';                  // Specifies the name of the log project.
        $logstore = 'your_logstore';                // Specifies the name of your Logstore.
        $client = new Aliyun_Log_Client($endpoint, $accessKeyId, $accessKey);
        # List names of all Logstores for the current log project.
        $req1 = new Aliyun_Log_Models_ListLogstoresRequest($project);
        $res1 = $client->listLogstores($req1);
        var_dump($res1);
     }            

  3. Download dependencies to the /tmp/code directory.

     cd /tmp/code
     git clone https://github.com/aliyun/aliyun-log-php-sdk.git           

Package files and upload them to Function Compute.

You must package the files that you want instead of all code folders. After the files are packaged, ensure that the files of the handler function are placed in the root directory of the package.

• In Windows, you can select all the files in specific code directories of the function, right-click these files, and compress the files into a code package in the ZIP format.
• In Linux, when you call the zip command, specify all the files in the code directories as source files to generate a deployment code package. For example, you can use zip code.zip /home/code/*.

After the compression is complete, you can click the function name in the Function Compute console. On the page that appears, click the Code tab, and select Import from OSS or Upload Zip File to upload the code package.

Call external commands

If you want to run external tools, such as shell scripts and executable files compiled in C++ or Go in your PHP functions, you can package and upload the tools and code together, and run external commands to use these tools. You can use the following PHP methods to execute external programs: exec, system, and shell-exec.

The following sample code shows how to use the exec method to call a shell script.

<?php
function handler($evt, $ctx){
    $script = $_ENV['FC_FUNC_CODE_PATH'] . '/script.sh';
    $a = exec("bash " . $script, $out, $status);
    print_r($a);
    var_dump($out);
    print_r($status);
}