IAP Client Libraries

This page shows how to get started with the Google APIs Client Libraries for the Cloud IAP API. Read more about the client libraries for Cloud APIs in Client Libraries Explained.

Installing the client library

PHP

For more information, see Using PHP on Google Cloud.

composer require google/apiclient

Setting up authentication

To run the client library, you must first set up authentication by creating a service account and setting an environment variable. Complete the following steps to set up authentication. For other ways to authenticate, see the GCP authentication documentation.

Cloud Console

  1. In the Cloud Console, go to the Create service account key page.

    Go to the Create Service Account Key page
  2. From the Service account list, select New service account.
  3. In the Service account name field, enter a name.

  4. From the Role list, select Project > Owner.

    Note: The Role field authorizes your service account to access resources. You can view and change this field later by using the Cloud Console. If you are developing a production app, specify more granular permissions than Project > Owner. For more information, see granting roles to service accounts.
  5. Click Create. A JSON file that contains your key downloads to your computer.

Command line

You can run the following commands using the Cloud SDK on your local machine, or in Cloud Shell.

  1. Create the service account. Replace [NAME] with a name for the service account. 

    gcloud iam service-accounts create [NAME]

  2. Grant permissions to the service account. Replace [PROJECT_ID] with your project ID. 

    gcloud projects add-iam-policy-binding [PROJECT_ID] --member "serviceAccount:[NAME]@[PROJECT_ID].iam.gserviceaccount.com" --role "roles/owner"
    Note: The Role field authorizes your service account to access resources. You can view and change this field later by using Cloud Console. If you are developing a production app, specify more granular permissions than Project > Owner. For more information, see granting roles to service accounts.

  3. Generate the key file. Replace [FILE_NAME] with a name for the key file. 

    gcloud iam service-accounts keys create [FILE_NAME].json --iam-account [NAME]@[PROJECT_ID].iam.gserviceaccount.com

Provide authentication credentials to your application code by setting the environment variable GOOGLE_APPLICATION_CREDENTIALS. Replace [PATH] with the file path of the JSON file that contains your service account key. This variable only applies to your current shell session, so if you open a new session, set the variable again.

Linux or macOS

export GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

For example:

export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/my-key.json"

Windows

With PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

For example:

$env:GOOGLE_APPLICATION_CREDENTIALS="C:\Users\username\Downloads\my-key.json"

With command prompt:

set GOOGLE_APPLICATION_CREDENTIALS=[PATH]

Using the client library

The following example shows how to use the client library.

PHP

<?php
/**
 * Copyright 2017 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace Google\Cloud\Samples\Iap;

use Symfony\Component\Console\Application;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;

# Includes the autoloader for libraries installed with composer
require __DIR__ . '/vendor/autoload.php';

$application = new Application('Iap');

// Create request Command.
$application->add((new Command('request'))
    ->addArgument('url', InputArgument::REQUIRED, 'The Identity-Aware Proxy-protected URL to fetch.')
    ->addArgument('clientId', InputArgument::REQUIRED, 'The client ID used by Identity-Aware Proxy.')
    ->addArgument('serviceAccountPath', InputArgument::REQUIRED, 'Path for the service account you want to use.')
    ->setDescription('Make a request to an IAP-protected resource using a service account.')
    ->setHelp(<<<EOF
The <info>%command.name%</info> command makes a request to an IAP-protected resource.
    <info>php %command.full_name%</info>

EOF
    )
    ->setCode(function ($input, $output) {
        $response = make_iap_request(
            $input->getArgument('url'),
            $input->getArgument('clientId'),
            $input->getArgument('serviceAccountPath'));
        $response_body = (string)$response->getBody();
        print('Printing out response body:');
        print($response_body);
    })
);

// Create a validate Command.
$application->add((new Command('validate'))
    ->addArgument('jwt', InputArgument::REQUIRED, 'A JWT from the X-Goog-Iap-Jwt-Assertion header')
    ->addArgument('projectNumber', InputArgument::REQUIRED, 'The project *number* for your Google Cloud project. This is returned by gcloud projects describe $PROJECT_ID or in the Project Info card in Cloud Console.')
    ->addArgument('projectId', InputArgument::REQUIRED, 'The project ID for your Google Cloud Platform project.')
    ->setDescription('Validates the JWT in the X-Goog-Iap-Jwt-Assertion header of an IAP-protected resource.')
    ->setHelp(<<<EOF
The <info>%command.name%</info> command makes a request to an IAP-protected resource and then validates the JWT.
    <info>php %command.full_name%</info>

EOF
    )
    ->setCode(function ($input, $output) {
        $user_identity = validate_jwt_from_app_engine(
            $input->getArgument('jwt'),
            $input->getArgument('projectNumber'),
            $input->getArgument('projectId'));
        print('Printing user identity information from ID token payload:');
        printf('sub: %s', $user_identity['sub']);
        printf('email: %s', $user_identity['email']);
    })
);

if (getenv('PHPUNIT_TESTS') === '1') {
    return $application;
}

$application->run();

Additional resources