feat: user agent v2.1 second revision

- Move the user agent middleware after the signing step in order to gather signature metrics.
- Add request compression metric gathering.
- Add specific testing for signatures.
- Add specific testing for request compression.
- Add specific testing for s3 encryption clients.
- Add credentials metric gathering logic.
- Add tests for credentials metrics.
- Make existent credentials tests to work with the new field `source`. For example, for tests around profile credentials the source property for credentials MUST be `profile`. The default value for this field is `static`.

src/AwsClient.php

@@ -280,10 +280,6 @@ public function __construct(array $args)
         if (isset($args['with_resolved'])) {
             $args['with_resolved']($config);
         }
-        MetricsBuilder::appendMetricsCaptureMiddleware(
-            $this->getHandlerList(),
-            MetricsBuilder::RESOURCE_MODEL
-        );
         $this->addUserAgentMiddleware($config);
     }
 
@@ -453,7 +449,7 @@ private function addSignatureMiddleware(array $args)
         }
 
         $resolver = static function (
-            CommandInterface $c
+            CommandInterface $command
         ) use (
                 $api,
                 $provider,
@@ -465,17 +461,17 @@ private function addSignatureMiddleware(array $args)
             $handlerList
         ) {
             if (!$configuredSignatureVersion) {
-                if (!empty($c['@context']['signing_region'])) {
-                    $region = $c['@context']['signing_region'];
+                if (!empty($command['@context']['signing_region'])) {
+                    $region = $command['@context']['signing_region'];
                 }
-                if (!empty($c['@context']['signing_service'])) {
-                    $name = $c['@context']['signing_service'];
+                if (!empty($command['@context']['signing_service'])) {
+                    $name = $command['@context']['signing_service'];
                 }
-                if (!empty($c['@context']['signature_version'])) {
-                    $signatureVersion = $c['@context']['signature_version'];
+                if (!empty($command['@context']['signature_version'])) {
+                    $signatureVersion = $command['@context']['signature_version'];
                 }
 
-                $authType = $api->getOperation($c->getName())['authtype'];
+                $authType = $api->getOperation($command->getName())['authtype'];
                 switch ($authType){
                     case 'none':
                         $signatureVersion = 'anonymous';
@@ -490,20 +486,21 @@ private function addSignatureMiddleware(array $args)
             }
 
             if ($signatureVersion === 'v4a') {
-                $commandSigningRegionSet = !empty($c['@context']['signing_region_set'])
-                    ? implode(', ', $c['@context']['signing_region_set'])
+                $commandSigningRegionSet = !empty($command['@context']['signing_region_set'])
+                    ? implode(', ', $command['@context']['signing_region_set'])
                     : null;
 
                 $region = $signingRegionSet
                     ?? $commandSigningRegionSet
                     ?? $region;
-
-                MetricsBuilder::appendMetricsCaptureMiddleware(
-                    $handlerList,
-                    MetricsBuilder::SIGV4A_SIGNING
-                );
             }
 
+            // Capture signature metric
+            $command->getMetricsBuilder()->identifyMetricByValueAndAppend(
+                'signature',
+                $signatureVersion
+            );
+
             return SignatureProvider::resolve($provider, $signatureVersion, $name, $region);
         };
         $this->handlerList->appendSign(
@@ -607,9 +604,19 @@ private function addEndpointV2Middleware()
         );
     }
 
+    /**
+     * Appends the user agent middleware.
+     * This middleware MUST be appended after the
+     * signature middleware `addSignatureMiddleware`,
+     * so that metrics around signatures are properly
+     * captured.
+     *
+     * @param $args
+     * @return void
+     */
     private function addUserAgentMiddleware($args)
     {
-        $this->getHandlerList()->prependSign(
+        $this->getHandlerList()->appendSign(
             UserAgentMiddleware::wrap($args),
             'user-agent'
         );

src/Command.php

@@ -29,7 +29,12 @@ class Command implements CommandInterface
      * @param array       $args           Arguments to pass to the command
      * @param HandlerList $list           Handler list
      */
-    public function __construct($name, array $args = [], ?HandlerList $list = null)
+    public function __construct(
+        $name,
+        array $args = [],
+        ?HandlerList $list = null,
+        ?MetricsBuilder $metricsBuilder = null
+    )
     {
         $this->name = $name;
         $this->data = $args;
@@ -41,7 +46,7 @@ public function __construct($name, array $args = [], ?HandlerList $list = null)
         if (!isset($this->data['@context'])) {
             $this->data['@context'] = [];
         }
-        $this->metricsBuilder = new MetricsBuilder();
+        $this->metricsBuilder = $metricsBuilder ?: new MetricsBuilder();
     }
 
     public function __clone()

src/Credentials/AssumeRoleCredentialProvider.php

@@ -52,7 +52,10 @@ public function __invoke()
         $client = $this->client;
         return $client->assumeRoleAsync($this->assumeRoleParams)
             ->then(function (Result $result) {
-                return $this->client->createCredentials($result);
+                return $this->client->createCredentials(
+                    $result,
+                    CredentialSources::STS_ASSUME_ROLE
+                );
             })->otherwise(function (\RuntimeException $exception) {
                 throw new CredentialsException(
                     "Error in retrieving assume role credentials.",

src/Credentials/AssumeRoleWithWebIdentityCredentialProvider.php

@@ -36,13 +36,17 @@ class AssumeRoleWithWebIdentityCredentialProvider
 
     /** @var integer */
     private $tokenFileReadAttempts;
+    /** @var string */
+    private $source;
 
     /**
      * The constructor attempts to load config from environment variables.
      * If not set, the following config options are used:
      *  - WebIdentityTokenFile: full path of token filename
      *  - RoleArn: arn of role to be assumed
      *  - SessionName: (optional) set by SDK if not provided
+     *  - source: To identify if the provider was sourced by a profile or
+     *    from environment definition. Default will be `sts_web_id_token`.
      *
      * @param array $config Configuration options
      * @throws \InvalidArgumentException
@@ -66,15 +70,9 @@ public function __construct(array $config = [])
         $this->retries = (int) getenv(self::ENV_RETRIES) ?: (isset($config['retries']) ? $config['retries'] : 3);
         $this->authenticationAttempts = 0;
         $this->tokenFileReadAttempts = 0;
-
-        $this->session = isset($config['SessionName'])
-            ? $config['SessionName']
-            : 'aws-sdk-php-' . round(microtime(true) * 1000);
-
-        $region = isset($config['region'])
-            ? $config['region']
-            : 'us-east-1';
-
+        $this->session = $config['SessionName']
+            ?? 'aws-sdk-php-' . round(microtime(true) * 1000);
+        $region = $config['region'] ?? 'us-east-1';
         if (isset($config['client'])) {
             $this->client = $config['client'];
         } else {
@@ -84,6 +82,9 @@ public function __construct(array $config = [])
                 'version' => 'latest'
             ]);
         }
+
+        $this->source = $config['source']
+            ?? CredentialSources::STS_WEB_ID_TOKEN;
     }
 
     /**
@@ -160,7 +161,10 @@ public function __invoke()
                 $this->authenticationAttempts++;
             }
 
-            yield $this->client->createCredentials($result);
+            yield $this->client->createCredentials(
+                $result,
+                $this->source
+            );
         });
     }
 }

src/Credentials/CredentialProvider.php

@@ -302,7 +302,8 @@ public static function env()
                         $secret,
                         $token,
                         null,
-                        $accountId
+                        $accountId,
+                        CredentialSources::ENVIRONMENT
                     )
                 );
             }
@@ -417,7 +418,8 @@ public static function assumeRoleWithWebIdentityCredentialProvider(array $config
                     'WebIdentityTokenFile' => $tokenFromEnv,
                     'SessionName' => $sessionName,
                     'client' => $stsClient,
-                    'region' => $region
+                    'region' => $region,
+                    'source' => CredentialSources::ENVIRONMENT_STS_WEB_ID_TOKEN
                 ]);
 
                 return $provider();
@@ -446,7 +448,8 @@ public static function assumeRoleWithWebIdentityCredentialProvider(array $config
                         'WebIdentityTokenFile' => $profile['web_identity_token_file'],
                         'SessionName' => $sessionName,
                         'client' => $stsClient,
-                        'region' => $region
+                        'region' => $region,
+                        'source' => CredentialSources::PROFILE_STS_WEB_ID_TOKEN
                     ]);
 
                     return $provider();
@@ -553,7 +556,8 @@ public static function ini($profile = null, $filename = null, array $config = []
                     $data[$profile]['aws_secret_access_key'],
                     $data[$profile]['aws_session_token'],
                     null,
-                    !empty($data[$profile]['aws_account_id']) ? $data[$profile]['aws_account_id'] : null
+                    $data[$profile]['aws_account_id'] ?? null,
+                    CredentialSources::PROFILE
                 )
             );
         };
@@ -641,7 +645,8 @@ public static function process($profile = null, $filename = null)
                     $processData['SecretAccessKey'],
                     $processData['SessionToken'],
                     $expires,
-                    $accountId
+                    $accountId,
+                    CredentialSources::PROCESS
                 )
             );
         };
@@ -724,7 +729,10 @@ private static function loadRoleProfile(
             'RoleArn' => $roleArn,
             'RoleSessionName' => $roleSessionName
         ]);
-        $credentials = $stsClient->createCredentials($result);
+        $credentials = $stsClient->createCredentials(
+            $result,
+            CredentialSources::STS_ASSUME_ROLE
+        );
 
         return Promise\Create::promiseFor($credentials);
     }
@@ -918,7 +926,8 @@ private static function getSsoCredentials($profiles, $ssoProfileName, $filename,
                 $ssoCredentials['secretAccessKey'],
                 $ssoCredentials['sessionToken'],
                 $expiration,
-                $ssoProfile['sso_account_id']
+                $ssoProfile['sso_account_id'],
+                CredentialSources::SSO
             )
         );
     }
@@ -978,7 +987,8 @@ private static function getSsoCredentialsLegacy($profiles, $ssoProfileName, $fil
                 $ssoCredentials['secretAccessKey'],
                 $ssoCredentials['sessionToken'],
                 $expiration,
-                $ssoProfile['sso_account_id']
+                $ssoProfile['sso_account_id'],
+                CredentialSources::SSO_LEGACY
             )
         );
     }

src/Credentials/CredentialSources.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Aws\Credentials;
+
+/**
+ * @internal
+ */
+class CredentialSources
+{
+    const STATIC = 'static';
+    const ENVIRONMENT = 'env';
+    const STS_WEB_ID_TOKEN = 'sts_web_id_token';
+    const ENVIRONMENT_STS_WEB_ID_TOKEN = 'env_sts_web_id_token';
+    const PROFILE_STS_WEB_ID_TOKEN = 'profile_sts_web_id_token';
+    const STS_ASSUME_ROLE = 'sts_assume_role';
+    const PROFILE = 'profile';
+    const IMDS = 'instance_profile_provider';
+    const ECS = 'ecs';
+    const SSO = 'sso';
+    const SSO_LEGACY = 'sso_legacy';
+    const PROCESS = 'process';
+}

src/Credentials/Credentials.php

@@ -16,6 +16,7 @@ class Credentials extends AwsCredentialIdentity implements
     private $token;
     private $expires;
     private $accountId;
+    private $source;
 
     /**
      * Constructs a new BasicAWSCredentials object, with the specified AWS
@@ -26,13 +27,21 @@ class Credentials extends AwsCredentialIdentity implements
      * @param string $token   Security token to use
      * @param int    $expires UNIX timestamp for when credentials expire
      */
-    public function __construct($key, $secret, $token = null, $expires = null, $accountId = null)
+    public function __construct(
+        $key,
+        $secret,
+        $token = null,
+        $expires = null,
+        $accountId = null,
+        $source = CredentialSources::STATIC
+    )
     {
         $this->key = trim((string) $key);
         $this->secret = trim((string) $secret);
         $this->token = $token;
         $this->expires = $expires;
         $this->accountId = $accountId;
+        $this->source = $source;
     }
 
     public static function __set_state(array $state)
@@ -42,7 +51,8 @@ public static function __set_state(array $state)
             $state['secret'],
             $state['token'],
             $state['expires'],
-            $state['accountId']
+            $state['accountId'],
+            $state['source'] ?? null
         );
     }
 
@@ -76,14 +86,20 @@ public function getAccountId()
         return $this->accountId;
     }
 
+    public function getSource()
+    {
+        return $this->source;
+    }
+
     public function toArray()
     {
         return [
             'key'     => $this->key,
             'secret'  => $this->secret,
             'token'   => $this->token,
             'expires' => $this->expires,
-            'accountId' =>  $this->accountId
+            'accountId' =>  $this->accountId,
+            'source' => $this->source
         ];
     }
 
@@ -111,6 +127,7 @@ public function __unserialize($data)
         $this->token = $data['token'];
         $this->expires = $data['expires'];
         $this->accountId = $data['accountId'] ?? null;
+        $this->source = $data['source'] ?? null;
     }
 
     /**

src/Credentials/EcsCredentialProvider.php

@@ -91,7 +91,8 @@ public function __invoke()
                             $result['SecretAccessKey'],
                             $result['Token'],
                             strtotime($result['Expiration']),
-                            $result['AccountId'] ?? null
+                            $result['AccountId'] ?? null,
+                            CredentialSources::ECS
                         );
                     })->otherwise(function ($reason) {
                         $reason = is_array($reason) ? $reason['exception'] : $reason;

src/Credentials/InstanceProfileProvider.php

@@ -227,7 +227,8 @@ public function __invoke($previousCredentials = null)
                     $result['SecretAccessKey'],
                     $result['Token'],
                     strtotime($result['Expiration']),
-                    $result['AccountId'] ?? null
+                    $result['AccountId'] ?? null,
+                    CredentialSources::IMDS
                 );
             }