Project: Cloudstack Client Generator

Aug 15th, 2011

🦖 This post was published in 2011 and is most likely outdated.

This is command line tool that fetches and parses the online reference for CloudStack API and generates the client class in PHP with in-code documentation.

See project on github

You can generate a client in any language (Java, python, C++, ObjectiveC, etc.) by adding class templates to the templates/ directory. See the last PHP client generated.

Description

The table of content of the API reference lists all the methods. Each method has its own page. The data that the script fetches for each method is:

the method name
the method description
for each argument:
- the argument name
- the argument description
- wether if the argument is required or not

Here is an example of a method generated that has one arugment required ($id) and one not ($forced):

/**
 * Stops a virtual machine.
 *
 * @param string $id The ID of the virtual machine
 * @param string $forced Force stop the VM.
 *     The caller knows the VM is stopped.
 */

public function stopVirtualMachine($id, $forced = "") {
    $this->request("stopVirtualMachine", array(
        'id' => $id,
        'forced' => $forced,
    ));
}

Usage

Just run the script, it will generate all the methods.

php generate.php class

Output:

abstract class BaseCloudStackClient {
    abstract protected function request($method, $args);

    /**
     * Stops a virtual machine.
     *
     * @param string $id The ID of the virtual machine
     * @param string $forced Force stop the VM.
     *     The caller knows the VM is stopped.
     */
    
    public function stopVirtualMachine($id, $forced = "") {
        $this->request("stopVirtualMachine", array(
            'id' => $id,
            'forced' => $forced,
        ));
    }

    ...
}

Configuration

The configuration is set in config.yml with the Yaml format:

# URL of the API reference table of contents
api_ref_toc_url: http://download.cloud.com/releases/2.2.0/api_2.2.4/TOC_User.html

# Configuration for the PHP generated code
php:
    class_name: BaseCloudStackClient
    use_camel_case: true

# Camel case values
camel_case:
    account: account
    accounts: accounts
    accounttype: accountType
    ...

Camel Case

You can either choose to have generated code with the same variable names than in the documentation, securitygroupnames for instance, or to have them in camel case, like securityGroupNames by setting use_camel_case to true in the configuration file.

Debuging

As the DOM of the online documentation may change, here is some tools to inquire the change. Three steps are crucial:

The URL of the online documentation table of content of the **latest** version of the API. To be modified in the config file.
The link black list: links to ignore in all the links from the table of content. To be modified in the function getAllLinks() of generate.php.
The page scraper if the DOM change, to be modified in the function fetchMethodData() in generate.php.

The code is well documented, it should not be too difficult to understand and tweak it.

Dump links

This command is great to debug a change in the URL pattern of the online documentation. It should output all the links that are on the table of contents (the URL is in the config file):

php generate.php dump-links

Example:

$ php generate.php dump-links
user/deployVirtualMachine.html
user/destroyVirtualMachine.html
user/rebootVirtualMachine.html
user/startVirtualMachine.html
user/stopVirtualMachine.html
user/resetPasswordForVirtualMachine.html
...

Dump method data

This command shows what data is fetched from the page of one method. Example:

$ php generate.php dump-method-data stopVirtualMachine
Array
(
    [name] => stopVirtualMachine
    [description] => Stops a virtual machine.
    [params] => Array
        (
            [0] => Array
                (
                    [name] => id
                    [description] => The ID of the virtual machine
                    [required] => true
                )

            [1] => Array
                (
                    [name] => forced
                    [description] => Force stop the VM.  The caller knows the VM is stopped.
                    [required] => false
                )

        )

)

Method

This command generates the PHP code for that method. The following example will output the code given at the begin of the README:

php generate.php method stopVirtualMachine

🌱 Quentin Pleplé