feat: Add support for grpc only gapic

composer.json

@@ -16,6 +16,7 @@
             "Testing\\BasicBidiStreaming\\": "tests/Unit/ProtoTests/BasicBidiStreaming/out/src",
             "Testing\\BasicClientStreaming\\": "tests/Unit/ProtoTests/BasicClientStreaming/out/src",
             "Testing\\BasicDiregapic\\": "tests/Unit/ProtoTests/BasicDiregapic/out/src",
+            "Testing\\BasicGrpcOnly\\": "tests/Unit/ProtoTests/BasicGrpcOnly/out/src",
             "Testing\\BasicLro\\": "tests/Unit/ProtoTests/BasicLro/out/src",
             "Testing\\BasicOneof\\": "tests/Unit/ProtoTests/BasicOneof/out/src",
             "Testing\\BasicOneofNew\\": "tests/Unit/ProtoTests/BasicOneofNew/out/src",

rules_php_gapic/php_gapic.bzl

@@ -69,10 +69,8 @@ def php_gapic_srcjar(
     # Transport.
     if transport == None:
         transport = "grpc+rest"
-    if transport == "grpc":
-        fail("Error: gRPC-only PHP GAPIC libraries are not yet supported")
-    if transport != "grpc+rest" and transport != "rest":
-        fail("Error: Only 'grpc+rest' or 'rest' transports are supported")
+    if transport != "grpc+rest" and transport != "rest" and transport != "grpc":
+        fail("Error: Only 'grpc+rest', 'rest' or `grpc` transports are supported")
 
     # Set plugin arguments.
     plugin_args = ["metadata"]  # Generate the gapic_metadata.json file.

src/Generation/GapicClientGenerator.php

@@ -443,7 +443,7 @@ private function getClientDefaults(): PhpClassMember
 
         // TODO: Consolidate setting all the known array values together.
         // We do this here to maintain the existing sensible ordering.
-        if ($this->serviceDetails->transportType === Transport::GRPC_REST) {
+        if ($this->serviceDetails->transportType !== Transport::REST) {
             $clientDefaultValues['gcpApiConfigPath'] =
                 AST::concat(AST::__DIR__, "/../resources/{$this->serviceDetails->grpcConfigFilename}");
         }

src/Generation/GapicClientV2Generator.php

@@ -478,15 +478,23 @@ private function defaultTransport()
 
     private function supportedTransports()
     {
-        if ($this->serviceDetails->transportType !== Transport::REST) {
-            return null;
+        if ($this->serviceDetails->transportType === Transport::REST) {
+            return AST::method('supportedTransports')
+                ->withPhpDocText('Implements ClientOptionsTrait::supportedTransports.')
+                ->withAccess(Access::PRIVATE, Access::STATIC)
+                ->withBody(AST::block(
+                    AST::return(AST::array(['rest']))
+                ));
+        }
+
+        if ($this->serviceDetails->transportType === Transport::GRPC) {
+            return AST::method('supportedTransports')
+                ->withPhpDocText('Implements ClientOptionsTrait::supportedTransports.')
+                ->withAccess(Access::PRIVATE, Access::STATIC)
+                ->withBody(AST::block(
+                    AST::return(AST::array(['grpc', 'grpc-fallback']))
+                ));
         }
-        return AST::method('supportedTransports')
-            ->withPhpDocText('Implements GapicClientTrait::supportedTransports.')
-            ->withAccess(Access::PRIVATE, Access::STATIC)
-            ->withBody(AST::block(
-                AST::return(AST::array(['rest']))
-            ));
     }
 
     private function construct(): PhpClassMember
@@ -498,30 +506,30 @@ private function construct(): PhpClassMember
         $options = AST::var('options');
         $optionsParam = AST::param(ResolvedType::array(), $options, AST::array([]));
         $clientOptions = AST::var('clientOptions');
+        $transportType = $this->serviceDetails->transportType;
 
-        // Assumes there are only two transport types.
-        $isGrpcRest = $this->serviceDetails->transportType === Transport::GRPC_REST;
-
-        $restTransportDocText = 'At the moment, supports only `rest`.';
-        $grpcTransportDocText = 'May be either the string `rest` or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.';
         $transportDocText =
             PhpDoc::text(
                 'The transport used for executing network requests. ',
-                $isGrpcRest ? $grpcTransportDocText : $restTransportDocText,
+                $this->transportDocText($transportType),
                 '*Advanced usage*: Additionally, it is possible to pass in an already instantiated',
                 // TODO(vNext): Don't use a fully-qualified type here.
                 $ctx->type(Type::fromName(TransportInterface::class), true),
                 'object. Note that when this object is provided, any settings in $transportConfig, and any $apiEndpoint',
                 'setting, will be ignored.'
             );
+
+        $transportConfigSampleValues = [
+            'grpc' => AST::arrayEllipsis(),
+            'rest' => AST::arrayEllipsis()
+        ];
 
-        $transportConfigSampleValues = [];
-        if ($isGrpcRest) {
-            $transportConfigSampleValues['grpc'] = AST::arrayEllipsis();
+        if (Transport::isGrpcOnly($transportType)) {
+            unset($transportConfigSampleValues['rest']);
+        } elseif (Transport::isRestOnly($transportType)) {
+            unset($transportConfigSampleValues['grpc']);
         }
-        // Set this value here, don't initialize it, so we can maintain alphabetical order
-        // for the resulting printed doc.
-        $transportConfigSampleValues['rest'] = AST::arrayEllipsis();
+
         $transportConfigDocText =
             PhpDoc::text(
                 'Configuration options that will be used to construct the transport. Options for',
@@ -539,22 +547,26 @@ private function construct(): PhpClassMember
                 'See the',
                 AST::call(
                     $ctx->type(
-                        Type::fromName($isGrpcRest ? GrpcTransport::class : RestTransport::class),
+                        Type::fromName(
+                            Transport::isRestOnly($transportType) ? 
+                                RestTransport::class :
+                                GrpcTransport::class
+                        ),
                         true
                     ),
                     AST::method('build')
                 )(),
-                $isGrpcRest ? 'and' : '',
-                $isGrpcRest
-                    ? AST::call(
+                Transport::isGRPCRest($transportType) ? 'and' : '',
+                Transport::isGRPCRest($transportType) ? 
+                    AST::call(
                         $ctx->type(
                             Type::fromName(RestTransport::class),
                             true
                         ),
                         AST::method('build')
                     )()
                     : '',
-                $isGrpcRest ? 'methods ' : 'method ',
+                Transport::isGRPCRest($transportType) ? 'methods ' : 'method ',
                 'for the supported options.'
             );
         return AST::method('__construct')
@@ -661,6 +673,19 @@ private function construct(): PhpClassMember
             ));
     }
 
+    private function transportDocText(int $transportType): string
+    {
+        if (Transport::isRestOnly($transportType)) {
+            return 'At the moment, supports only `rest`.';
+        }
+
+        if (Transport::isGrpcOnly($transportType)) {
+            return 'At the moment, supports only `grpc`.';
+        }
+
+        return 'May be either the string `rest` or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.';;
+    }
+
     private function rpcMethod(MethodDetails $method): PhpClassMember
     {
         $request = AST::var('request');

src/Utils/Transport.php

@@ -24,6 +24,7 @@ class Transport
     // supported in the future (e.g. gRPC only).
     public const GRPC_REST = 1;
     public const REST = 2;
+    public const GRPC = 3;
 
     /**
      *  Returns true if the given transport string indicates that grpc+rest transports
@@ -38,9 +39,29 @@ public static function parseTransport(?string $transport): int
             return static::REST;
         }
         if ($transport === "grpc") {
-            throw new \Exception("gRPC-only PHP clients are not supported at this time");
+            return static::GRPC;
         }
 
         throw new \Exception("Transport $transport not supported");
     }
+
+    public static function isRestOnly(int $transport): bool
+    {
+        return Transport::compareTransports(Transport::REST, $transport);
+    }
+
+    public static function isGrpcOnly(int $transport): bool
+    {
+        return Transport::compareTransports(Transport::GRPC, $transport);
+    }
+
+    public static function isGRPCRest(int $transport): bool
+    {
+        return Transport::compareTransports(Transport::GRPC_REST, $transport);
+    }
+
+    private static function compareTransports(int $transportA, int $transportB): bool
+    {
+        return $transportA === $transportB;
+    }
 }

tests/Integration/BUILD.bazel

@@ -354,6 +354,7 @@ php_gapic_library(
     grpc_service_config = "@com_google_googleapis//google/cloud/redis/v1:redis_grpc_service_config.json",
     service_yaml = "@com_google_googleapis//google/cloud/redis/v1:redis_v1.yaml",
     migration_mode = "MIGRATION_MODE_UNSPECIFIED",
+    transport = "grpc",
     deps = [
         ":redis_php_grpc",
         ":redis_php_proto",

tests/Integration/goldens/redis/src/V1/Client/CloudRedisClient.php

@@ -131,7 +131,6 @@ private static function getClientDefaults()
             'apiEndpoint' => self::SERVICE_ADDRESS . ':' . self::DEFAULT_SERVICE_PORT,
             'clientConfig' => __DIR__ . '/../resources/cloud_redis_client_config.json',
             'descriptorsConfigPath' => __DIR__ . '/../resources/cloud_redis_descriptor_config.php',
-            'gcpApiConfigPath' => __DIR__ . '/../resources/cloud_redis_grpc_config.json',
             'credentialsConfig' => [
                 'defaultScopes' => self::$serviceScopes,
             ],
@@ -143,6 +142,15 @@ private static function getClientDefaults()
         ];
     }
 
+    /** Implements ClientOptionsTrait::supportedTransports. */
+    private static function supportedTransports()
+    {
+        return [
+            'grpc',
+            'grpc-fallback',
+        ];
+    }
+
     /**
      * Return an OperationsClient object with the same endpoint as $this.
      *
@@ -263,9 +271,8 @@ public static function parseName(string $formattedName, string $template = null)
      *           default this settings points to the default client config file, which is
      *           provided in the resources folder.
      *     @type string|TransportInterface $transport
-     *           The transport used for executing network requests. May be either the string
-     *           `rest` or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.
-     *           *Advanced usage*: Additionally, it is possible to pass in an already
+     *           The transport used for executing network requests. At the moment, supports only
+     *           `grpc`. *Advanced usage*: Additionally, it is possible to pass in an already
      *           instantiated {@see \Google\ApiCore\Transport\TransportInterface} object. Note
      *           that when this object is provided, any settings in $transportConfig, and any
      *           $apiEndpoint setting, will be ignored.
@@ -275,10 +282,8 @@ public static function parseName(string $formattedName, string $template = null)
      *           example:
      *           $transportConfig = [
      *               'grpc' => [...],
-     *               'rest' => [...],
      *           ];
-     *           See the {@see \Google\ApiCore\Transport\GrpcTransport::build()} and
-     *           {@see \Google\ApiCore\Transport\RestTransport::build()} methods for the
+     *           See the {@see \Google\ApiCore\Transport\GrpcTransport::build()} method for the
      *           supported options.
      *     @type callable $clientCertSource
      *           A callable which returns the client cert as a string. This can be used to

tests/Integration/goldens/redis/src/V1/Gapic/CloudRedisGapicClient.php

@@ -347,9 +347,8 @@ public function resumeOperation($operationName, $methodName = null)
      *           default this settings points to the default client config file, which is
      *           provided in the resources folder.
      *     @type string|TransportInterface $transport
-     *           The transport used for executing network requests. May be either the string
-     *           `rest` or `grpc`. Defaults to `grpc` if gRPC support is detected on the system.
-     *           *Advanced usage*: Additionally, it is possible to pass in an already
+     *           The transport used for executing network requests. At the moment, supports only
+     *           `rest`. *Advanced usage*: Additionally, it is possible to pass in an already
      *           instantiated {@see \Google\ApiCore\Transport\TransportInterface} object. Note
      *           that when this object is provided, any settings in $transportConfig, and any
      *           $apiEndpoint setting, will be ignored.
@@ -358,11 +357,9 @@ public function resumeOperation($operationName, $methodName = null)
      *           each supported transport type should be passed in a key for that transport. For
      *           example:
      *           $transportConfig = [
-     *               'grpc' => [...],
      *               'rest' => [...],
      *           ];
-     *           See the {@see \Google\ApiCore\Transport\GrpcTransport::build()} and
-     *           {@see \Google\ApiCore\Transport\RestTransport::build()} methods for the
+     *           See the {@see \Google\ApiCore\Transport\RestTransport::build()} method for the
      *           supported options.
      *     @type callable $clientCertSource
      *           A callable which returns the client cert as a string. This can be used to

tests/Unit/ProtoTests/BasicGrpcOnly/basic-grpc-only.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package testing.basicgrpconly;
+
+// php_namespace option not included; to test generating namespace from proto package.
+
+import "google/api/annotations.proto";
+import "google/api/client.proto";
+import "google/api/field_behavior.proto";
+
+// This is a basicGrpcOnly service.
+service BasicGrpcOnly {
+  option (google.api.default_host) = "basicGrpcOnly.example.com";
+}

tests/Unit/ProtoTests/BasicGrpcOnly/basic_grpc_only_service.yaml

@@ -0,0 +1,6 @@
+type: google.api.Service
+config_version: 3
+
+authentication:
+  rules:
+  - selector: 'testing.basicGrpcOnly.BasicGrpcOnly.*'