feat: add GCP Secret Manager OpenFeature provider

.release-please-manifest.json

@@ -11,6 +11,7 @@
   "providers/statsig": "0.2.1",
   "providers/multiprovider": "0.0.3",
   "providers/ofrep": "0.0.1",
+  "providers/gcp": "0.0.1",
   "tools/junit-openfeature": "0.2.1",
   "tools/flagd-http-connector": "0.0.4",
   "tools/flagd-api": "1.0.0",

pom.xml

@@ -1,6 +1,9 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<?xml version="1.0" encoding="UTF-8" ?>
+<project
+    xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"
+>
     <modelVersion>4.0.0</modelVersion>
 
     <groupId>dev.openfeature.contrib</groupId>
@@ -45,19 +48,23 @@
         <module>providers/optimizely</module>
         <module>providers/multiprovider</module>
         <module>providers/ofrep</module>
+        <module>providers/gcp</module>
         <module>tools/flagd-http-connector</module>
     </modules>
 
     <scm>
-        <connection>scm:git:https://github.com/open-feature/java-sdk-contrib.git</connection>
-        <developerConnection>scm:git:https://github.com/open-feature/java-sdk-contrib.git</developerConnection>
+        <connection
+        >scm:git:https://github.com/open-feature/java-sdk-contrib.git</connection>
+        <developerConnection
+        >scm:git:https://github.com/open-feature/java-sdk-contrib.git</developerConnection>
         <url>https://github.com/open-feature/java-sdk-contrib</url>
     </scm>
 
     <properties>
         <toolchain.jdk.version>[21,)</toolchain.jdk.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <project.reporting.outputEncoding
+        >UTF-8</project.reporting.outputEncoding>
         <module-name>${groupId}.${artifactId}</module-name>
         <javadoc.failOnWarnings>true</javadoc.failOnWarnings>
         <!--  This is required for later correct replacement of surefireArgLine -->
@@ -237,7 +244,8 @@
                 <configuration>
                     <archive>
                         <manifestEntries>
-                            <Automatic-Module-Name>${module-name}</Automatic-Module-Name>
+                            <Automatic-Module-Name
+                            >${module-name}</Automatic-Module-Name>
                         </manifestEntries>
                     </archive>
                 </configuration>
@@ -285,8 +293,10 @@
                         </executions>
                         <configuration>
                             <skip>${maven.deploy.skip}</skip>
-                            <repository>https://repo1.maven.org/maven2</repository>
-                            <snapshotRepository>https://central.sonatype.com/repository/maven-snapshots</snapshotRepository>
+                            <repository
+                            >https://repo1.maven.org/maven2</repository>
+                            <snapshotRepository
+                            >https://central.sonatype.com/repository/maven-snapshots</snapshotRepository>
                             <snapshotServerId>central</snapshotServerId>
                         </configuration>
                     </plugin>
@@ -310,7 +320,8 @@
                         <artifactId>maven-javadoc-plugin</artifactId>
                         <version>3.12.0</version>
                         <configuration>
-                            <failOnWarnings>${javadoc.failOnWarnings}</failOnWarnings>
+                            <failOnWarnings
+                            >${javadoc.failOnWarnings}</failOnWarnings>
                             <excludePackageNames>
                                 dev.openfeature.flagd.grpc
                             </excludePackageNames>
@@ -338,7 +349,8 @@
                         <configuration>
                             <projectType>library</projectType>
                             <schemaVersion>1.3</schemaVersion>
-                            <includeBomSerialNumber>true</includeBomSerialNumber>
+                            <includeBomSerialNumber
+                            >true</includeBomSerialNumber>
                             <includeCompileScope>true</includeCompileScope>
                             <includeProvidedScope>true</includeProvidedScope>
                             <includeRuntimeScope>true</includeRuntimeScope>
@@ -384,7 +396,8 @@
                         <configuration>
                             <publishingServerId>central</publishingServerId>
                             <autoPublish>true</autoPublish>
-                            <skipPublishing>${maven.deploy.skip}</skipPublishing>
+                            <skipPublishing
+                            >${maven.deploy.skip}</skipPublishing>
                         </configuration>
                     </plugin>
                     <!-- End publish to maven central -->
@@ -412,7 +425,8 @@
                             <consoleOutput>true</consoleOutput>
                             <failsOnError>true</failsOnError>
                             <linkXRef>false</linkXRef>
-                            <excludeGeneratedSources>true</excludeGeneratedSources>
+                            <excludeGeneratedSources
+                            >true</excludeGeneratedSources>
                         </configuration>
                         <dependencies>
                             <dependency>
@@ -437,7 +451,8 @@
                         <artifactId>maven-pmd-plugin</artifactId>
                         <version>3.28.0</version>
                         <configuration>
-                            <excludeRoots>${basedir}/target/generated-sources/</excludeRoots>
+                            <excludeRoots
+                            >${basedir}/target/generated-sources/</excludeRoots>
                         </configuration>
                         <executions>
                             <execution>
@@ -456,7 +471,8 @@
                         <artifactId>spotbugs-maven-plugin</artifactId>
                         <version>4.9.8.3</version>
                         <configuration>
-                            <excludeFilterFile>spotbugs-exclusions.xml</excludeFilterFile>
+                            <excludeFilterFile
+                            >spotbugs-exclusions.xml</excludeFilterFile>
                             <plugins>
                                 <plugin>
                                     <groupId>com.h3xstream.findsecbugs</groupId>
@@ -501,8 +517,8 @@
                                         <include>.gitignore</include>
                                     </includes>
                                     <!-- define the steps to apply to those files -->
-                                    <trimTrailingWhitespace/>
-                                    <endWithNewline/>
+                                    <trimTrailingWhitespace />
+                                    <endWithNewline />
                                     <indent>
                                         <spaces>true</spaces>
                                         <spacesPerTab>4</spacesPerTab>
@@ -511,16 +527,16 @@
                             </formats>
                             <!-- define a language-specific format -->
                             <java>
-                                <palantirJavaFormat/>
+                                <palantirJavaFormat />
 
                                 <indent>
                                     <spaces>true</spaces>
                                     <spacesPerTab>4</spacesPerTab>
                                 </indent>
-                                <importOrder/>
+                                <importOrder />
 
-                                <removeUnusedImports/>
-                                <formatAnnotations/>
+                                <removeUnusedImports />
+                                <formatAnnotations />
 
                             </java>
                         </configuration>

providers/gcp/CHANGELOG.md

@@ -0,0 +1,7 @@
+# Changelog
+
+## 0.0.1
+
+### ✨ New Features
+
+* Initial release with scaffolding for Google Cloud and GCP Secret Manager OpenFeature provider.

providers/gcp/README.md

@@ -0,0 +1,121 @@
+# GCP Provider
+
+An OpenFeature provider that reads feature flags from Google Cloud. Currently supports [Google Cloud Secret Manager](https://cloud.google.com/secret-manager), purpose-built for secrets requiring versioning, rotation, and fine-grained IAM access control.
+
+## Installation
+
+<!-- x-release-please-start-version -->
+```xml
+<dependency>
+    <groupId>dev.openfeature.contrib.providers</groupId>
+    <artifactId>gcp</artifactId>
+    <version>0.0.1</version>
+</dependency>
+```
+<!-- x-release-please-end-version -->
+
+## Quick Start
+
+```java
+import dev.openfeature.contrib.providers.gcp.GcpSecretManagerProvider;
+import dev.openfeature.contrib.providers.gcp.GcpSecretManagerProviderOptions;
+import dev.openfeature.sdk.OpenFeatureAPI;
+
+GcpSecretManagerProviderOptions options = GcpSecretManagerProviderOptions.builder()
+    .projectId("my-gcp-project")
+    .build();
+
+OpenFeatureAPI.getInstance().setProvider(new GcpSecretManagerProvider(options));
+
+// Evaluate a boolean flag stored as secret "enable-dark-mode" with value "true"
+boolean darkMode = OpenFeatureAPI.getInstance().getClient()
+    .getBooleanValue("enable-dark-mode", false);
+```
+
+## How It Works
+
+Each feature flag is stored as an individual **secret** in GCP Secret Manager. The flag key maps directly to the secret name (with an optional prefix). The `latest` version is accessed by default.
+
+Supported raw value formats:
+
+| Flag type | Secret value example |
+|-----------|---------------------|
+| Boolean   | `true` or `false`   |
+| Integer   | `42`                |
+| Double    | `3.14`              |
+| String    | `dark-mode`         |
+| Object    | `{"color":"blue","level":3}` |
+
+## Authentication
+
+The provider uses [Application Default Credentials (ADC)](https://cloud.google.com/docs/authentication/provide-credentials-adc) by default. No explicit credentials are required when running on GCP infrastructure (Cloud Run, GKE, Compute Engine) or when `gcloud auth application-default login` has been run locally.
+
+To use explicit credentials:
+
+```java
+import com.google.auth.oauth2.ServiceAccountCredentials;
+import java.io.FileInputStream;
+
+GoogleCredentials credentials = ServiceAccountCredentials.fromStream(
+    new FileInputStream("/path/to/service-account-key.json"));
+
+GcpSecretManagerProviderOptions options = GcpSecretManagerProviderOptions.builder()
+    .projectId("my-gcp-project")
+    .credentials(credentials)
+    .build();
+```
+
+## Configuration Options
+
+| Option | Type | Default | Description |
+|--------|------|---------|-------------|
+| `projectId` | `String` | *(required)* | GCP project ID that owns the secrets |
+| `credentials` | `GoogleCredentials` | `null` (ADC) | Explicit credentials; falls back to Application Default Credentials when null |
+| `secretVersion` | `String` | `"latest"` | Secret version to access. Use `"latest"` for the current version or a numeric string (e.g. `"3"`) to pin to a specific version |
+| `cacheExpiry` | `Duration` | `5 minutes` | How long fetched secret values are cached before re-fetching from GCP |
+| `cacheMaxSize` | `int` | `500` | Maximum number of secret values held in the in-memory cache |
+| `namePrefix` | `String` | `null` | Optional prefix prepended to every flag key. E.g. prefix `"ff-"` maps flag `"my-flag"` to secret `"ff-my-flag"` |
+
+## Advanced Usage
+
+### Pinning to a specific secret version
+
+```java
+GcpSecretManagerProviderOptions options = GcpSecretManagerProviderOptions.builder()
+    .projectId("my-gcp-project")
+    .secretVersion("5")  // always use version 5
+    .build();
+```
+
+### Secret name prefix
+
+```java
+GcpSecretManagerProviderOptions options = GcpSecretManagerProviderOptions.builder()
+    .projectId("my-gcp-project")
+    .namePrefix("feature-flags/")
+    .build();
+```
+
+### Tuning cache for high-throughput scenarios
+
+Secret Manager has API quotas (10,000 access operations per minute per project). Use a longer `cacheExpiry` to stay within quota.
+
+```java
+GcpSecretManagerProviderOptions options = GcpSecretManagerProviderOptions.builder()
+    .projectId("my-gcp-project")
+    .cacheExpiry(Duration.ofMinutes(10))
+    .cacheMaxSize(1000)
+    .build();
+```
+
+## Running Integration Tests
+
+Integration tests require real GCP credentials and pre-created test secrets.
+
+1. Configure ADC: `gcloud auth application-default login`
+2. Create test secrets in your project (see `GcpSecretManagerProviderIntegrationTest` for the required secret names and values)
+3. Run:
+
+```bash
+GCP_PROJECT_ID=my-project mvn verify -pl providers/gcp -Dgroups=integration
+```