includes/libs/virtualrest/SwiftVirtualRESTService.php

   1 <?php
   2 /**
   3  * Virtual HTTP service client for Swift
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 /**
  24  * Example virtual rest service for OpenStack Swift
  25  * @TODO: caching support (APC/memcached)
  26  * @since 1.23
  27  */
  28 class SwiftVirtualRESTService extends VirtualRESTService {
  29         /** @var array */
  30         protected $authCreds;
  31         /** @var int UNIX timestamp */
  32         protected $authSessionTimestamp = 0;
  33         /** @var int UNIX timestamp */
  34         protected $authErrorTimestamp = null;
  35         /** @var int */
  36         protected $authCachedStatus = null;
  37         /** @var string */
  38         protected $authCachedReason = null;
  39
  40         /**
  41          * @param array $params Key/value map
  42          *   - swiftAuthUrl       : Swift authentication server URL
  43          *   - swiftUser          : Swift user used by MediaWiki (account:username)
  44          *   - swiftKey           : Swift authentication key for the above user
  45          *   - swiftAuthTTL       : Swift authentication TTL (seconds)
  46          */
  47         public function __construct( array $params ) {
  48                 // set up defaults and merge them with the given params
  49                 $mparams = array_merge( array(
  50                         'name' => 'swift'
  51                 ), $params );
  52                 parent::__construct( $mparams );
  53         }
  54
  55         /**
  56          * @return int|bool HTTP status on cached failure
  57          */
  58         protected function needsAuthRequest() {
  59                 if ( !$this->authCreds ) {
  60                         return true;
  61                 }
  62                 if ( $this->authErrorTimestamp !== null ) {
  63                         if ( ( time() - $this->authErrorTimestamp ) < 60 ) {
  64                                 return $this->authCachedStatus; // failed last attempt; don't bother
  65                         } else { // actually retry this time
  66                                 $this->authErrorTimestamp = null;
  67                         }
  68                 }
  69                 // Session keys expire after a while, so we renew them periodically
  70                 return ( ( time() - $this->authSessionTimestamp ) > $this->params['swiftAuthTTL'] );
  71         }
  72
  73         protected function applyAuthResponse( array $req ) {
  74                 $this->authSessionTimestamp = 0;
  75                 list( $rcode, $rdesc, $rhdrs, $rbody, $rerr ) = $req['response'];
  76                 if ( $rcode >= 200 && $rcode <= 299 ) { // OK
  77                         $this->authCreds = array(
  78                                 'auth_token'  => $rhdrs['x-auth-token'],
  79                                 'storage_url' => $rhdrs['x-storage-url']
  80                         );
  81                         $this->authSessionTimestamp = time();
  82                         return true;
  83                 } elseif ( $rcode === 403 ) {
  84                         $this->authCachedStatus = 401;
  85                         $this->authCachedReason = 'Authorization Required';
  86                         $this->authErrorTimestamp = time();
  87                         return false;
  88                 } else {
  89                         $this->authCachedStatus = $rcode;
  90                         $this->authCachedReason = $rdesc;
  91                         $this->authErrorTimestamp = time();
  92                         return null;
  93                 }
  94         }
  95
  96         public function onRequests( array $reqs, Closure $idGeneratorFunc ) {
  97                 $result = array();
  98                 $firstReq = reset( $reqs );
  99                 if ( $firstReq && count( $reqs ) == 1 && isset( $firstReq['isAuth'] ) ) {
 100                         // This was an authentication request for work requests...
 101                         $result = $reqs; // no change
 102                 } else {
 103                         // These are actual work requests...
 104                         $needsAuth = $this->needsAuthRequest();
 105                         if ( $needsAuth === true ) {
 106                                 // These are work requests and we don't have any token to use.
 107                                 // Replace the work requests with an authentication request.
 108                                 $result = array(
 109                                         $idGeneratorFunc() => array(
 110                                                 'method'  => 'GET',
 111                                                 'url'     => $this->params['swiftAuthUrl'] . "/v1.0",
 112                                                 'headers' => array(
 113                                                         'x-auth-user' => $this->params['swiftUser'],
 114                                                         'x-auth-key'  => $this->params['swiftKey'] ),
 115                                                 'isAuth'  => true,
 116                                                 'chain'   => $reqs
 117                                         )
 118                                 );
 119                         } elseif ( $needsAuth !== false ) {
 120                                 // These are work requests and authentication has previously failed.
 121                                 // It is most efficient to just give failed pseudo responses back for
 122                                 // the original work requests.
 123                                 foreach ( $reqs as $key => $req ) {
 124                                         $req['response'] = array(
 125                                                 'code'     => $this->authCachedStatus,
 126                                                 'reason'   => $this->authCachedReason,
 127                                                 'headers'  => array(),
 128                                                 'body'     => '',
 129                                                 'error'    => ''
 130                                         );
 131                                         $result[$key] = $req;
 132                                 }
 133                         } else {
 134                                 // These are work requests and we have a token already.
 135                                 // Go through and mangle each request to include a token.
 136                                 foreach ( $reqs as $key => $req ) {
 137                                         // The default encoding treats the URL as a REST style path that uses
 138                                         // forward slash as a hierarchical delimiter (and never otherwise).
 139                                         // Subclasses can override this, and should be documented in any case.
 140                                         $parts = array_map( 'rawurlencode', explode( '/', $req['url'] ) );
 141                                         $req['url'] = $this->authCreds['storage_url'] . '/' . implode( '/', $parts );
 142                                         $req['headers']['x-auth-token'] = $this->authCreds['auth_token'];
 143                                         $result[$key] = $req;
 144                                         // @TODO: add ETag/Content-Length and such as needed
 145                                 }
 146                         }
 147                 }
 148                 return $result;
 149         }
 150
 151         public function onResponses( array $reqs, Closure $idGeneratorFunc ) {
 152                 $firstReq = reset( $reqs );
 153                 if ( $firstReq && count( $reqs ) == 1 && isset( $firstReq['isAuth'] ) ) {
 154                         $result = array();
 155                         // This was an authentication request for work requests...
 156                         if ( $this->applyAuthResponse( $firstReq ) ) {
 157                                 // If it succeeded, we can subsitute the work requests back.
 158                                 // Call this recursively in order to munge and add headers.
 159                                 $result = $this->onRequests( $firstReq['chain'], $idGeneratorFunc );
 160                         } else {
 161                                 // If it failed, it is most efficient to just give failing
 162                                 // pseudo-responses back for the actual work requests.
 163                                 foreach ( $firstReq['chain'] as $key => $req ) {
 164                                         $req['response'] = array(
 165                                                 'code'     => $this->authCachedStatus,
 166                                                 'reason'   => $this->authCachedReason,
 167                                                 'headers'  => array(),
 168                                                 'body'     => '',
 169                                                 'error'    => ''
 170                                         );
 171                                         $result[$key] = $req;
 172                                 }
 173                         }
 174                 } else {
 175                         $result = $reqs; // no change
 176                 }
 177                 return $result;
 178         }
 179 }