feat: support for GoFeatureFlagProvider

pom.xml

@@ -15,13 +15,14 @@
     <description>OpenFeature bundle for Dropwizard</description>
 
     <properties>
-        <!-- Support Java 8 as the same language level supported by the Openfeature SDK -->
-        <java.version>8</java.version>
+        <!-- Support Java 11 as the same language level supported by the Openfeature SDK -->
+        <maven.compiler.release>11</maven.compiler.release>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <dropwizard.version>5.0.0</dropwizard.version>
         <openfeature-sdk.version>1.18.2</openfeature-sdk.version>
         <openfeature-contrib-providers-flagd.version>0.11.17</openfeature-contrib-providers-flagd.version>
+        <openfeature-contrib-providers-go-feature-flag.version>1.0.1</openfeature-contrib-providers-go-feature-flag.version>
         <jacoco-maven-plugin.version>0.8.14</jacoco-maven-plugin.version>
         <maven-compiler-plugin.version>3.14.1</maven-compiler-plugin.version>
         <maven-gpg-plugin.version>3.2.8</maven-gpg-plugin.version>
@@ -31,6 +32,7 @@
         <maven-surefire-plugin.version>3.5.4</maven-surefire-plugin.version>
         <maven-failsafe-plugin.version>3.5.4</maven-failsafe-plugin.version>
         <mockito.version>5.20.0</mockito.version>
+        <testcontainers.version>1.21.3</testcontainers.version>
         <central-publishing-maven-plugin.version>0.9.0</central-publishing-maven-plugin.version>
     </properties>
 
@@ -75,8 +77,15 @@
                 <artifactId>mockito-bom</artifactId>
                 <version>${mockito.version}</version>
                 <type>pom</type>
-                <scope>test</scope>
+                <scope>import</scope>
             </dependency>
+            <dependency>
+                <groupId>org.testcontainers</groupId>
+                <artifactId>testcontainers-bom</artifactId>
+                <version>${testcontainers.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+        </dependency>
         </dependencies>
     </dependencyManagement>
 
@@ -112,6 +121,12 @@
             <artifactId>flagd</artifactId>
             <version>${openfeature-contrib-providers-flagd.version}</version>
         </dependency>
+        <dependency>
+            <groupId>dev.openfeature.contrib.providers</groupId>
+            <artifactId>go-feature-flag</artifactId>
+            <version>${openfeature-contrib-providers-go-feature-flag.version}</version>
+        </dependency>
+
         <dependency>
             <groupId>io.dropwizard</groupId>
             <artifactId>dropwizard-testing</artifactId>
@@ -127,6 +142,21 @@
             <artifactId>mockito-junit-jupiter</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>testcontainers</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -165,8 +195,7 @@
                     <artifactId>maven-compiler-plugin</artifactId>
                     <version>${maven-compiler-plugin.version}</version>
                     <configuration>
-                        <source>${java.version}</source>
-                        <target>${java.version}</target>
+                      <release>${maven.compiler.release}</release>
                     </configuration>
                 </plugin>
                 <plugin>

src/main/java/io/github/sideshowcoder/dropwizard_openfeature/GoFeatureFlagConfiguration.java

@@ -0,0 +1,26 @@
+package io.github.sideshowcoder.dropwizard_openfeature;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProviderOptions;
+import dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProviderOptions.GoFeatureFlagProviderOptionsBuilder;
+import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidOptions;
+import jakarta.validation.constraints.NotNull;
+
+public class GoFeatureFlagConfiguration {
+
+    @JsonProperty
+    @NotNull
+    private String endpoint;
+
+    public GoFeatureFlagProviderOptions getGoFeatureFlagProviderOptions() throws InvalidOptions {
+        GoFeatureFlagProviderOptionsBuilder builder = GoFeatureFlagProviderOptions.builder();
+
+        builder.endpoint(endpoint);
+
+        GoFeatureFlagProviderOptions options = builder.build();
+        options.validate();
+        return options;
+    }
+
+}

src/main/java/io/github/sideshowcoder/dropwizard_openfeature/OpenFeatureBundle.java

@@ -1,6 +1,9 @@
 package io.github.sideshowcoder.dropwizard_openfeature;
 
 import dev.openfeature.contrib.providers.flagd.FlagdProvider;
+import dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProvider;
+import dev.openfeature.contrib.providers.gofeatureflag.GoFeatureFlagProviderOptions;
+import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidOptions;
 import dev.openfeature.sdk.Client;
 import dev.openfeature.sdk.FeatureProvider;
 import dev.openfeature.sdk.OpenFeatureAPI;
@@ -44,6 +47,13 @@ private synchronized void initializeFeatureProvider(OpenFeatureConfiguration con
             case FLAGD:
                 featureProvider = new FlagdProvider(config.getFlagd().getFlagdOptions());
                 break;
+            case GOFEATUREFLAG:
+                try {
+                    featureProvider = new GoFeatureFlagProvider(config.getGoFeatureFlag().getGoFeatureFlagProviderOptions());
+                } catch(InvalidOptions e) {
+                    new RuntimeException(e);
+                }
+                break;
         }
     }
 }

src/main/java/io/github/sideshowcoder/dropwizard_openfeature/OpenFeatureConfiguration.java

@@ -11,6 +11,10 @@ public class OpenFeatureConfiguration {
     @JsonProperty
     private FlagdConfiguration flagd = new FlagdConfiguration();
 
+    @Valid
+    @JsonProperty
+    private GoFeatureFlagConfiguration gofeatureflag = new GoFeatureFlagConfiguration();
+
     @Valid
     @JsonProperty
     private OpenFeatureHealthCheckConfiguration healthcheck = new OpenFeatureHealthCheckConfiguration();
@@ -28,6 +32,14 @@ public void setFlagd(FlagdConfiguration flagd) {
         this.flagd = flagd;
     }
 
+    public GoFeatureFlagConfiguration getGoFeatureFlag() {
+        return gofeatureflag;
+    }
+
+    public void setGoFeatureFlag(GoFeatureFlagConfiguration gofeatureflag) {
+        this.gofeatureflag = gofeatureflag;
+    }
+
     public OpenFeatureHealthCheckConfiguration getHealthcheck() {
         return healthcheck;
     }

src/main/java/io/github/sideshowcoder/dropwizard_openfeature/ProviderType.java

@@ -2,5 +2,6 @@
 
 public enum ProviderType {
     FLAGD,
+    GOFEATUREFLAG,
     INMEMORY;
 }

src/test/java/io/github/sideshowcoder/dropwizard_openfeature/OpenFeatureBundleGoFeatureFlagProviderTest.java

@@ -0,0 +1,65 @@
+package io.github.sideshowcoder.dropwizard_openfeature;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.containers.wait.strategy.Wait;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+import org.testcontainers.utility.MountableFile;
+
+import com.codahale.metrics.health.HealthCheck;
+
+import dev.openfeature.sdk.Client;
+import dev.openfeature.sdk.EvaluationContext;
+import dev.openfeature.sdk.ImmutableContext;
+import dev.openfeature.sdk.OpenFeatureAPI;
+import io.dropwizard.testing.ResourceHelpers;
+import io.dropwizard.testing.junit5.DropwizardAppExtension;
+import io.dropwizard.testing.junit5.DropwizardExtensionsSupport;
+import io.github.sideshowcoder.dropwizard_openfeature.helpers.App;
+import io.github.sideshowcoder.dropwizard_openfeature.helpers.Config;
+
+@Testcontainers
+@ExtendWith(DropwizardExtensionsSupport.class)
+public class OpenFeatureBundleGoFeatureFlagProviderTest {
+
+    @Container
+    private static GenericContainer<?> goFeatureFlagRelay = createGoFeatureFlagContainer();
+
+    private static GenericContainer<?> createGoFeatureFlagContainer() {
+        GenericContainer<?> container = new GenericContainer<>(DockerImageName.parse("gofeatureflag/go-feature-flag:latest"))
+            .withCopyFileToContainer(MountableFile.forClasspathResource("goff-proxy.yaml"), "/goff/goff-proxy.yaml")
+            .withCopyFileToContainer(MountableFile.forClasspathResource("go-feature-flags-flags.yaml"), "/goff/flags.yaml");
+
+        container.setPortBindings(List.of("1031:1031"));
+        container.waitingFor(Wait.forHttp("/health"));
+
+        return container;
+    }
+
+    private static final DropwizardAppExtension<Config> APP = new DropwizardAppExtension<>(
+        App.class,
+        ResourceHelpers.resourceFilePath("go-feature-flag-provider-config.yml")
+    );
+
+    @Test
+    public void initializesHealthCheck() throws Exception {
+        HealthCheck.Result healthcheckResult = APP.getEnvironment().healthChecks().runHealthCheck("openfeature-health-check");
+        assertTrue(healthcheckResult.isHealthy());
+    }
+
+    @Test
+    public void providesFeatureFlagsViaInMemoryProvider() throws Exception {
+        Client client = OpenFeatureAPI.getInstance().getClient("go-feature-flag-client");
+        // GoFeatureFlags requires a target key for all queries!
+        EvaluationContext ctx = new ImmutableContext("target");
+        assertEquals("red", client.getStringValue("staticstringflag", "not-expected-value", ctx));
+    }
+}

src/test/resources/basic-flagd-config.yml

@@ -1,4 +1,4 @@
 host: flagd
 port: 8082
 resolver: rpc
-cacheType: disabled
+cacheType: disabled

src/test/resources/go-feature-flag-provider-config.yml

@@ -0,0 +1,4 @@
+openfeature:
+  provider: gofeatureflag
+  gofeatureflag:
+    endpoint: "http://localhost:1031/"

src/test/resources/go-feature-flags-flags.yaml

@@ -0,0 +1,7 @@
+staticstringflag:
+  variations:
+   red: "red"
+   green: "green"
+   blue: "blue"
+  defaultRule:
+    variation: red

src/test/resources/goff-proxy.yaml

@@ -0,0 +1,3 @@
+retrievers:
+  - kind: file
+    path: /goff/flags.yaml