Merge pull request #749 from danistrebel/feat/grpc-http-gateway-gener…

…ator

Feat/grpc http gateway generator

CODEOWNERS

@@ -31,10 +31,11 @@
 /tools/apigee-x-trial-provision         @yuriylesyuk @danistrebel
 /tools/decrypt-hybrid-assets            @yuriylesyuk
 /tools/endpoints-oas-importer           @danistrebel
+/tools/grpc-http-gateway-generator      @danistrebel @omidtahouri
 /tools/hybrid-quickstart                @danistrebel
 /tools/oas-apigee-mock                  @markjkelly
 /tools/pipeline-linter                  @seymen @danistrebel
 /tools/pipeline-runner                  @seymen @danistrebel
-/tools/sf-dependency-list               @yuriylesyuk
 /tools/proxy-endpoint-unifier           @anaik91
-/tools/target-server-validator          @anaik91
+/tools/sf-dependency-list               @yuriylesyuk
+/tools/target-server-validator          @anaik91

README.md

@@ -92,7 +92,8 @@ Apigee products.
   A tool to unify/split proxy endpoints based on API basepath.
 - [Apigee Target Server Validator](tools/target-server-validator) -
   A tool to validate all targets in Target Servers & Apigee API Proxy Bundles.
-
+- [gRPC to HTTP Gateway Generator](tools/grpc-http-gateway-generator) -
+  Generate gateways to expose gRPC services with HTTP API management.
 ## Labs
 
 This folder contains raw assets used to generate content to teach a particular

tools/grpc-http-gateway-generator/README.md

@@ -0,0 +1,76 @@
+# gRPC to HTTP Gateway Generator
+
+The purpose of this tool is to generate a gRPC to HTTP gateway based on a protocol buffer.
+It leverages the [gRPC Gateway](https://github.com/grpc-ecosystem/grpc-gateway) project to generate the gateway code.
+
+The generated gRPC gateway can then be used to create HTTP adapters for gRPC services and use them in a classical HTTP REST-based API management environment.
+
+![Architecture Overview](./img/architecture.png)
+
+## Prerequisites
+
+The generator assumed you have the protobuf compiler `protoc` installed.
+
+Note that `protoc` is pre-installed on Cloud Shell.
+
+To install `protoc` with `apt`, run the following command:
+
+```sh
+apt install -y protobuf-compiler
+```
+
+## Generate the Gateway Code
+
+The gateway is generated based on a protocol buffer file that  you supply with the `--proto-path` flag:
+
+```sh
+./generate-gateway.sh --proto-path ./examples/currency.proto
+```
+
+Optionally you can also specify the desired output directory with the `--output` flag. If no output directory is specified the output will be generated in the `./generated/gateway` folder.
+
+## Run the Gateway
+
+You can run the gateway locally with the following commands and point to a gRPC server endpoint that runs on localhost port 9090: 
+
+```sh
+(cd generated/gateway && go run main.go --grpc-server-endpoint localhost:9090)
+```
+
+If you preffer to run the gateway as a container use the following commands to build and run the gateway container:
+
+```sh
+(cd generated/gateway && docker build . -t gateway:latest)
+docker run -p 8080:8080 -e GRPC_SERVER_ENDPOINT=localhost:9090 gateway:latest
+```
+
+## Try it out locally
+
+With the gateway running you can call the automatically generated API endpoints of the gateway to consume your gRPC service.
+
+With the gRPC Gateway pointing to an exposed currency service of the [microservice demo](https://github.com/GoogleCloudPlatform/microservices-demo) the currency conversion request would look like this:
+
+```sh
+curl -X POST localhost:8080/hipstershop.CurrencyService/Convert -d '{"from": {"units": 3, "currency_code": "USD", "nanos": 0}, "to_code": "CHF"}'
+```
+
+Whist the code to request supported currencies looks like this:
+
+```sh
+curl -X POST localhost:8080/hipstershop.CurrencyService/GetSupportedCurrencies
+```
+
+Note that the automatically generated API doesn't yet come in a RESTful format. This is one of the aspects that can be changed in an API management layer to improve the overall usability and security of the API.
+
+### Deploy to Cloud Run
+
+Once we've tested the gateway locally we can deploy it to Cloud Run for production use.
+
+```sh
+(cd generated/gateway && gcloud run deploy currency-grpc-gw --source . --allow-unauthenticated --region europe-west1 --project $PROJECT_ID)
+```
+
+## Expose the Cloud Run Service via Apigee
+
+With the Gateway running in Cloud Run we can now expose it via Apigee.
+For detailed instructions on how to expose a cloud run service in Apigee please see [this reference implementation](https://github.com/apigee/devrel/tree/main/references/cloud-run).

tools/grpc-http-gateway-generator/buf.gen.yaml

@@ -0,0 +1,24 @@
+# Copyright 2024 Google LLC
+#
+# 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.
+
+version: v1
+plugins:
+  - plugin: go
+    out: gen/go
+    opt:
+      - paths=source_relative
+  - plugin: go-grpc
+    out: gen/go
+    opt:
+      - paths=source_relative

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/currency-v1.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<APIProxy revision="1" name="currency-v1">
+</APIProxy>

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/policies/AM.SetConversionPath.xml

@@ -0,0 +1,21 @@
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<AssignMessage name="AM.SetConversionPath">
+    <AssignVariable>
+        <Name>flow.target.pathsuffix</Name>
+        <Value>/hipstershop.CurrencyService/Convert</Value>
+    </AssignVariable>
+</AssignMessage>

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/policies/AM.SetCurrenciesPath.xml

@@ -0,0 +1,21 @@
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<AssignMessage name="AM.SetCurrenciesPath">
+    <AssignVariable>
+        <Name>flow.target.pathsuffix</Name>
+        <Value>/hipstershop.CurrencyService/GetSupportedCurrencies</Value>
+    </AssignVariable>
+</AssignMessage>

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/policies/HM.SetTargetMethod.xml

@@ -0,0 +1,20 @@
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<HTTPModifier continueOnError="false" enabled="true" name="HM.SetTargetMethod">
+  <Set>
+    <Verb>POST</Verb>
+  </Set>
+</HTTPModifier>

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/policies/JS.SetTargetPath.xml

@@ -0,0 +1,18 @@
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<Javascript timeLimit="200" name="JS.SetTargetPath">
+    <ResourceURL>jsc://set-target-path.js</ResourceURL>
+</Javascript>

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/proxies/default.xml

@@ -0,0 +1,48 @@
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<ProxyEndpoint name="default">
+  <Flows>
+    <Flow>
+      <Condition>request.verb = "GET" and proxy.pathsuffix = "/currencies"</Condition>
+      <Request>
+        <Step>
+          <Name>AM.SetCurrenciesPath</Name>
+        </Step>
+      </Request>
+    </Flow>
+    <Flow>
+      <Condition>request.verb = "POST" and proxy.pathsuffix = "/convert"</Condition>
+      <Request>
+        <Step>
+          <Name>AM.SetConversionPath</Name>
+        </Step>
+      </Request>
+    </Flow>
+  </Flows>
+  <PostFlow>
+    <Request>
+      <Step>
+        <Name>HM.SetTargetMethod</Name>
+      </Step>
+    </Request>
+  </PostFlow>
+  <HTTPProxyConnection>
+    <BasePath>/currency/v1</BasePath>
+  </HTTPProxyConnection>
+  <RouteRule name="default">
+    <TargetEndpoint>default</TargetEndpoint>
+  </RouteRule>
+</ProxyEndpoint>

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/resources/jsc/set-target-path.js

@@ -0,0 +1,29 @@
+/*
+ Copyright 2024 Google LLC
+
+ 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.
+*/
+
+context.setVariable("target.copy.pathsuffix", false)
+
+var existingTargetUrl = context.getVariable("target.url");
+var targetPath = context.getVariable("flow.target.pathsuffix") || ""; // retrieve custom path, set by AM policies
+var queryString = context.getVariable("request.querystring") || "";
+
+var updatedTargetUrl = existingTargetUrl + targetPath + (queryString ? "?"+queryString : "");
+
+context.setVariable("target.url",
+    existingTargetUrl +                     // use target base URL
+    targetPath +                            // append custom path
+    (queryString ? "?"+queryString : "")  // conditionally append query params
+);

tools/grpc-http-gateway-generator/examples/currency-v1/apiproxy/targets/default.xml

@@ -0,0 +1,32 @@
+<!--
+ Copyright 2024 Google LLC
+
+ 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.
+-->
+<TargetEndpoint name="default">
+    <PreFlow>
+      <Request>
+        <Step>
+          <Name>JS.SetTargetPath</Name>
+        </Step>
+      </Request>
+    </PreFlow>
+    <HTTPTargetConnection>
+        <Authentication>
+            <GoogleIDToken>
+                <Audience>CLOUD_RUN_URL</Audience>
+            </GoogleIDToken>
+        </Authentication>
+        <URL>CLOUD_RUN_URL</URL>
+    </HTTPTargetConnection>
+</TargetEndpoint>