fix(openfeature): preserve source compatibility settings

Author: leoromanovsky

products/feature-flagging/feature-flagging-api/src/main/java/datadog/trace/api/openfeature/Provider.java

@@ -281,6 +281,8 @@ public static class Options {
 
     private long timeout = 30;
     private TimeUnit unit = SECONDS;
+    Boolean providerEnabled;
+    Boolean legacyProviderEnabled;
     String configurationSource;
     String cdnBaseUrl;
     String apiKey;
@@ -300,6 +302,11 @@ public Options configurationSource(final String configurationSource) {
       return this;
     }
 
+    public Options enabled(final boolean enabled) {
+      this.providerEnabled = enabled;
+      return this;
+    }
+
     public Options cdnBaseUrl(final String cdnBaseUrl) {
       this.cdnBaseUrl = cdnBaseUrl;
       return this;

products/feature-flagging/feature-flagging-api/src/main/java/datadog/trace/api/openfeature/ProviderRuntime.java

@@ -17,6 +17,9 @@ private ProviderRuntime() {}
 
   static Handle acquire(
       final RuntimeConfiguration configuration, final Consumer<ConfigurationSnapshot> listener) {
+    if (configuration.source == RuntimeConfiguration.Source.DISABLED) {
+      throw new IllegalStateException("Datadog OpenFeature provider is disabled by configuration");
+    }
     synchronized (LOCK) {
       if (shared == null) {
         shared = new SharedRuntime(configuration);

products/feature-flagging/feature-flagging-api/src/main/java/datadog/trace/api/openfeature/RuntimeConfiguration.java

@@ -13,7 +13,8 @@ final class RuntimeConfiguration {
 
   enum Source {
     CDN,
-    REMOTE_CONFIG
+    REMOTE_CONFIG,
+    DISABLED
   }
 
   final Source source;
@@ -25,13 +26,23 @@ private RuntimeConfiguration(final Source source, final HttpConfigurationOptions
   }
 
   static RuntimeConfiguration resolve(final Provider.Options options) {
+    final Boolean providerEnabled =
+        options.providerEnabled != null
+            ? options.providerEnabled
+            : booleanSetting("dd.feature.flags.enabled", "DD_FEATURE_FLAGS_ENABLED");
     final String sourceValue =
         first(
             options.configurationSource,
             setting(
                 "dd.feature.flags.configuration.source", "DD_FEATURE_FLAGS_CONFIGURATION_SOURCE"));
-    final Source source = parseSource(sourceValue);
-    if (source == Source.REMOTE_CONFIG) {
+    final Boolean legacyProviderEnabled =
+        options.legacyProviderEnabled != null
+            ? options.legacyProviderEnabled
+            : booleanSetting(
+                "dd.experimental.flagging.provider.enabled",
+                "DD_EXPERIMENTAL_FLAGGING_PROVIDER_ENABLED");
+    final Source source = resolveSource(providerEnabled, sourceValue, legacyProviderEnabled);
+    if (source != Source.CDN) {
       return new RuntimeConfiguration(source, null);
     }
 
@@ -72,19 +83,28 @@ static RuntimeConfiguration resolve(final Provider.Options options) {
             .build());
   }
 
-  private static Source parseSource(final String value) {
-    if (value == null || value.trim().isEmpty()) {
+  private static Source resolveSource(
+      final Boolean providerEnabled,
+      final String sourceValue,
+      final Boolean legacyProviderEnabled) {
+    if (Boolean.FALSE.equals(providerEnabled)) {
+      return Source.DISABLED;
+    }
+    if (sourceValue == null || sourceValue.trim().isEmpty()) {
+      if (legacyProviderEnabled != null) {
+        return legacyProviderEnabled ? Source.REMOTE_CONFIG : Source.DISABLED;
+      }
       return Source.CDN;
     }
-    final String normalized = value.trim().toLowerCase(Locale.ROOT);
+    final String normalized = sourceValue.trim().toLowerCase(Locale.ROOT);
     if ("agentless".equals(normalized) || "cdn".equals(normalized)) {
       return Source.CDN;
     }
     if ("remote_config".equals(normalized)) {
       return Source.REMOTE_CONFIG;
     }
     throw new IllegalArgumentException(
-        "Unsupported Feature Flagging configuration source: " + value);
+        "Unsupported Feature Flagging configuration source: " + sourceValue);
   }
 
   private static Duration seconds(final String value, final long defaultValue) {
@@ -105,6 +125,11 @@ private static String setting(final String property, final String environment) {
     return propertyValue != null ? propertyValue : System.getenv(environment);
   }
 
+  private static Boolean booleanSetting(final String property, final String environment) {
+    final String value = setting(property, environment);
+    return value == null ? null : Boolean.valueOf(value);
+  }
+
   private static String first(final String... values) {
     for (final String value : values) {
       if (value != null && !value.isEmpty()) {

products/feature-flagging/feature-flagging-api/src/test/java/datadog/trace/api/openfeature/ProviderTest.java

@@ -50,6 +50,36 @@ void selectsCdnByDefaultAndRemoteConfigExplicitly() {
             .source);
   }
 
+  @Test
+  void preservesStableAndLegacySourceSelection() {
+    assertEquals(
+        RuntimeConfiguration.Source.DISABLED,
+        RuntimeConfiguration.resolve(new Provider.Options().enabled(false)).source);
+
+    final Provider.Options legacyEnabled = new Provider.Options();
+    legacyEnabled.legacyProviderEnabled = true;
+    assertEquals(
+        RuntimeConfiguration.Source.REMOTE_CONFIG,
+        RuntimeConfiguration.resolve(legacyEnabled).source);
+
+    final Provider.Options legacyDisabled = new Provider.Options();
+    legacyDisabled.legacyProviderEnabled = false;
+    assertEquals(
+        RuntimeConfiguration.Source.DISABLED, RuntimeConfiguration.resolve(legacyDisabled).source);
+    assertEquals(
+        RuntimeConfiguration.Source.CDN,
+        RuntimeConfiguration.resolve(legacyDisabled.configurationSource("agentless")).source);
+  }
+
+  @Test
+  void disabledProviderDoesNotStartConfigurationSource() {
+    first = new Provider(new Provider.Options().enabled(false).initTimeout(10, MILLISECONDS));
+
+    final FatalError error =
+        assertThrows(FatalError.class, () -> first.initialize(new MutableContext()));
+    assertTrue(error.getMessage().contains("disabled by configuration"));
+  }
+
   @Test
   void providerOwnsCdnLifecycleWithoutAgent() throws Exception {
     final AtomicInteger requests = new AtomicInteger();