diff --git a/README.md b/README.md index e59b08246..d1c8b47b9 100644 --- a/README.md +++ b/README.md @@ -218,6 +218,14 @@ Once you've added a hook as a dependency, it can be registered at the global, cl ### Logging The Java SDK uses SLF4J. See the [SLF4J manual](https://slf4j.org/manual.html) for complete documentation. +Note that in accordance with the OpenFeature specification, the SDK doesn't generally log messages during flag evaluation. + +#### Logging Hook + +The Java SDK includes a `LoggingHook`, which logs detailed information at key points during flag evaluation, using SLF4J's structured logging API. +This hook can be particularly helpful for troubleshooting and debugging; simply attach it at the global, client or invocation level and ensure your log level is set to "debug". + +See [hooks](#hooks) for more information on configuring hooks. ### Domains diff --git a/src/main/java/dev/openfeature/sdk/HookSupport.java b/src/main/java/dev/openfeature/sdk/HookSupport.java index 8563096e2..52c5b9727 100644 --- a/src/main/java/dev/openfeature/sdk/HookSupport.java +++ b/src/main/java/dev/openfeature/sdk/HookSupport.java @@ -17,9 +17,18 @@ @SuppressWarnings({ "unchecked", "rawtypes" }) class HookSupport { - public void errorHooks(FlagValueType flagValueType, HookContext hookCtx, Exception e, List hooks, + public EvaluationContext beforeHooks(FlagValueType flagValueType, HookContext hookCtx, List hooks, Map hints) { - executeHooks(flagValueType, hooks, "error", hook -> hook.error(hookCtx, e, hints)); + Stream result = callBeforeHooks(flagValueType, hookCtx, hooks, hints); + return hookCtx.getCtx().merge( + result.reduce(hookCtx.getCtx(), (EvaluationContext accumulated, EvaluationContext current) -> { + return accumulated.merge(current); + })); + } + + public void afterHooks(FlagValueType flagValueType, HookContext hookContext, FlagEvaluationDetails details, + List hooks, Map hints) { + executeHooksUnchecked(flagValueType, hooks, hook -> hook.after(hookContext, details, hints)); } public void afterAllHooks(FlagValueType flagValueType, HookContext hookCtx, List hooks, @@ -27,9 +36,9 @@ public void afterAllHooks(FlagValueType flagValueType, HookContext hookCtx, List executeHooks(flagValueType, hooks, "finally", hook -> hook.finallyAfter(hookCtx, hints)); } - public void afterHooks(FlagValueType flagValueType, HookContext hookContext, FlagEvaluationDetails details, - List hooks, Map hints) { - executeHooksUnchecked(flagValueType, hooks, hook -> hook.after(hookContext, details, hints)); + public void errorHooks(FlagValueType flagValueType, HookContext hookCtx, Exception e, List hooks, + Map hints) { + executeHooks(flagValueType, hooks, "error", hook -> hook.error(hookCtx, e, hints)); } private void executeHooks( @@ -44,6 +53,17 @@ private void executeHooks( } } + // before, error, and finally hooks shouldn't throw + private void executeChecked(Hook hook, Consumer> hookCode, String hookMethod) { + try { + hookCode.accept(hook); + } catch (Exception exception) { + log.error("Unhandled exception when running {} hook {} (only 'after' hooks should throw)", hookMethod, + hook.getClass(), exception); + } + } + + // after hooks can throw in order to do validation private void executeHooksUnchecked( FlagValueType flagValueType, List hooks, Consumer> hookCode) { @@ -55,23 +75,6 @@ private void executeHooksUnchecked( } } - private void executeChecked(Hook hook, Consumer> hookCode, String hookMethod) { - try { - hookCode.accept(hook); - } catch (Exception exception) { - log.error("Exception when running {} hooks {}", hookMethod, hook.getClass(), exception); - } - } - - public EvaluationContext beforeHooks(FlagValueType flagValueType, HookContext hookCtx, List hooks, - Map hints) { - Stream result = callBeforeHooks(flagValueType, hookCtx, hooks, hints); - return hookCtx.getCtx().merge( - result.reduce(hookCtx.getCtx(), (EvaluationContext accumulated, EvaluationContext current) -> { - return accumulated.merge(current); - })); - } - private Stream callBeforeHooks(FlagValueType flagValueType, HookContext hookCtx, List hooks, Map hints) { // These traverse backwards from normal. diff --git a/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java b/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java index 05f7fea37..d8004e5de 100644 --- a/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java +++ b/src/main/java/dev/openfeature/sdk/OpenFeatureClient.java @@ -137,7 +137,6 @@ private FlagEvaluationDetails evaluateFlag(FlagValueType type, String key hookSupport.afterHooks(type, afterHookContext, details, mergedHooks, hints); } } catch (Exception e) { - log.error("Unable to correctly evaluate flag with key '{}'", key, e); if (details == null) { details = FlagEvaluationDetails.builder().build(); } diff --git a/src/main/java/dev/openfeature/sdk/hooks/logging/LoggingHook.java b/src/main/java/dev/openfeature/sdk/hooks/logging/LoggingHook.java new file mode 100644 index 000000000..716168f06 --- /dev/null +++ b/src/main/java/dev/openfeature/sdk/hooks/logging/LoggingHook.java @@ -0,0 +1,92 @@ +package dev.openfeature.sdk.hooks.logging; + +import dev.openfeature.sdk.ErrorCode; +import dev.openfeature.sdk.EvaluationContext; +import dev.openfeature.sdk.FlagEvaluationDetails; +import dev.openfeature.sdk.Hook; +import dev.openfeature.sdk.HookContext; +import dev.openfeature.sdk.exceptions.OpenFeatureError; +import java.util.Map; +import java.util.Optional; +import lombok.extern.slf4j.Slf4j; +import org.slf4j.spi.LoggingEventBuilder; + +/** + * A hook for logging flag evaluations. + * Useful for debugging. + * Flag evaluation data is logged at debug and error in before/after stages and error stages, respectively. + */ +@Slf4j +@edu.umd.cs.findbugs.annotations.SuppressFBWarnings(value = "RV_RETURN_VALUE_IGNORED", + justification = "we can ignore return values of chainables (builders) here") +public class LoggingHook implements Hook { + + static final String DOMAIN_KEY = "domain"; + static final String PROVIDER_NAME_KEY = "provider_name"; + static final String FLAG_KEY_KEY = "flag_key"; + static final String DEFAULT_VALUE_KEY = "default_value"; + static final String EVALUATION_CONTEXT_KEY = "evaluation_context"; + static final String ERROR_CODE_KEY = "error_code"; + static final String ERROR_MESSAGE_KEY = "error_message"; + static final String REASON_KEY = "reason"; + static final String VARIANT_KEY = "variant"; + static final String VALUE_KEY = "value"; + + private boolean includeEvaluationContext; + + /** + * Construct a new LoggingHook. + */ + public LoggingHook() { + this(false); + } + + /** + * Construct a new LoggingHook. + * @param includeEvaluationContext include a serialized evaluation context in the log message (defaults to false) + */ + public LoggingHook(boolean includeEvaluationContext) { + this.includeEvaluationContext = includeEvaluationContext; + } + + @Override + public Optional before(HookContext hookContext, Map hints) { + LoggingEventBuilder builder = log.atDebug(); + addCommonProps(builder, hookContext); + builder.log("Before stage"); + + return Optional.empty(); + } + + @Override + public void after(HookContext hookContext, FlagEvaluationDetails details, + Map hints) { + LoggingEventBuilder builder = log.atDebug() + .addKeyValue(REASON_KEY, details.getReason()) + .addKeyValue(VARIANT_KEY, details.getVariant()) + .addKeyValue(VALUE_KEY, details.getValue()); + addCommonProps(builder, hookContext); + builder.log("After stage"); + } + + @Override + public void error(HookContext hookContext, Exception error, Map hints) { + LoggingEventBuilder builder = log.atError() + .addKeyValue(ERROR_MESSAGE_KEY, error.getMessage()); + addCommonProps(builder, hookContext); + ErrorCode errorCode = error instanceof OpenFeatureError ? ((OpenFeatureError) error).getErrorCode() : null; + builder.addKeyValue(ERROR_CODE_KEY, errorCode); + builder.log("Error stage", error); + } + + private void addCommonProps(LoggingEventBuilder builder, HookContext hookContext) { + builder.addKeyValue(DOMAIN_KEY, hookContext.getClientMetadata().getDomain()) + .addKeyValue(PROVIDER_NAME_KEY, hookContext.getProviderMetadata().getName()) + .addKeyValue(FLAG_KEY_KEY, hookContext.getFlagKey()) + .addKeyValue(DEFAULT_VALUE_KEY, hookContext.getDefaultValue()); + + if (includeEvaluationContext) { + builder.addKeyValue(EVALUATION_CONTEXT_KEY, hookContext.getCtx()); + } + } +} diff --git a/src/test/java/dev/openfeature/sdk/FlagEvaluationSpecTest.java b/src/test/java/dev/openfeature/sdk/FlagEvaluationSpecTest.java index 6d2bca3a5..b4978cb4b 100644 --- a/src/test/java/dev/openfeature/sdk/FlagEvaluationSpecTest.java +++ b/src/test/java/dev/openfeature/sdk/FlagEvaluationSpecTest.java @@ -12,6 +12,7 @@ import static org.mockito.ArgumentMatchers.any; import static org.mockito.ArgumentMatchers.argThat; import static org.mockito.Mockito.mock; +import static org.mockito.Mockito.never; import static org.mockito.Mockito.spy; import static org.mockito.Mockito.times; import static org.mockito.Mockito.verify; @@ -25,12 +26,10 @@ import org.junit.jupiter.api.AfterEach; import org.junit.jupiter.api.BeforeEach; import org.junit.jupiter.api.Test; -import org.mockito.ArgumentMatchers; import org.mockito.Mockito; import org.simplify4u.slf4jmock.LoggerMock; import org.slf4j.Logger; -import dev.openfeature.sdk.exceptions.FlagNotFoundError; import dev.openfeature.sdk.exceptions.GeneralError; import dev.openfeature.sdk.fixtures.HookFixtures; import dev.openfeature.sdk.providers.memory.InMemoryProvider; @@ -266,17 +265,17 @@ public void initialize(EvaluationContext evaluationContext) throws Exception { assertEquals(TestConstants.BROKEN_MESSAGE, details.getErrorMessage()); } - @Specification(number="1.4.11", text="In the case of abnormal execution, the client SHOULD log an informative error message.") + @Specification(number="1.4.11", text="Methods, functions, or operations on the client SHOULD NOT write log messages.") @Test void log_on_error() throws NotImplementedException { FeatureProviderTestUtils.setFeatureProvider(new AlwaysBrokenProvider()); Client c = api.getClient(); FlagEvaluationDetails result = c.getBooleanDetails("test", false); assertEquals(Reason.ERROR.toString(), result.getReason()); - Mockito.verify(logger).error( - ArgumentMatchers.contains("Unable to correctly evaluate flag with key"), + Mockito.verify(logger, never()).error( + any(String.class), any(), - ArgumentMatchers.isA(FlagNotFoundError.class)); + any()); } @Specification(number="1.2.2", text="The client interface MUST define a metadata member or accessor, containing an immutable domain field or accessor of type string, which corresponds to the domain value supplied during client creation. In previous drafts, this property was called name. For backwards compatibility, implementations should consider name an alias to domain.") diff --git a/src/test/java/dev/openfeature/sdk/hooks/logging/LoggingHookTest.java b/src/test/java/dev/openfeature/sdk/hooks/logging/LoggingHookTest.java new file mode 100644 index 000000000..fad24caf7 --- /dev/null +++ b/src/test/java/dev/openfeature/sdk/hooks/logging/LoggingHookTest.java @@ -0,0 +1,167 @@ +package dev.openfeature.sdk.hooks.logging; + +import static org.mockito.ArgumentMatchers.any; +import static org.mockito.ArgumentMatchers.anyString; +import static org.mockito.ArgumentMatchers.argThat; +import static org.mockito.ArgumentMatchers.contains; +import static org.mockito.Mockito.mock; +import static org.mockito.Mockito.never; +import static org.mockito.Mockito.verify; +import static org.mockito.Mockito.when; + +import dev.openfeature.sdk.ClientMetadata; +import dev.openfeature.sdk.ErrorCode; +import dev.openfeature.sdk.EvaluationContext; +import dev.openfeature.sdk.FlagEvaluationDetails; +import dev.openfeature.sdk.FlagValueType; +import dev.openfeature.sdk.HookContext; +import dev.openfeature.sdk.ImmutableContext; +import dev.openfeature.sdk.Metadata; +import dev.openfeature.sdk.exceptions.GeneralError; +import lombok.SneakyThrows; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; +import org.simplify4u.slf4jmock.LoggerMock; +import org.slf4j.Logger; +import org.slf4j.spi.LoggingEventBuilder; + +class LoggingHookTest { + + private static final String FLAG_KEY = "some-key"; + private static final String DEFAULT_VALUE = "default"; + private static final String DOMAIN = "some-domain"; + private static final String PROVIDER_NAME = "some-provider"; + private static final String REASON = "some-reason"; + private static final String VALUE = "some-value"; + private static final String VARIANT = "some-variant"; + private static final String ERROR_MESSAGE = "some fake error!"; + private static final ErrorCode ERROR_CODE = ErrorCode.GENERAL; + + private HookContext hookContext; + private LoggingEventBuilder mockBuilder; + private Logger logger; + + @BeforeEach + void each() { + + // create a fake hook context + hookContext = HookContext.builder().flagKey(FLAG_KEY).defaultValue(DEFAULT_VALUE) + .clientMetadata(new ClientMetadata() { + @Override + public String getDomain() { + return DOMAIN; + } + }).providerMetadata(new Metadata() { + @Override + public String getName() { + return PROVIDER_NAME; + } + }).type(FlagValueType.BOOLEAN).ctx(new ImmutableContext()).build(); + + // mock logging + logger = mock(Logger.class); + mockBuilder = mock(LoggingEventBuilder.class); + when(mockBuilder.addKeyValue(anyString(), anyString())).thenReturn(mockBuilder); + when(logger.atDebug()).thenReturn(mockBuilder); + when(logger.atError()).thenReturn(mockBuilder); + LoggerMock.setMock(LoggingHook.class, logger); + } + + @SneakyThrows + @Test + void beforeLogsAllPropsExceptEvaluationContext() { + LoggingHook hook = new LoggingHook(); + hook.before(hookContext, null); + + verify(logger).atDebug(); + verifyCommonProps(mockBuilder); + verify(mockBuilder, never()).addKeyValue(anyString(), any(EvaluationContext.class)); + verify(mockBuilder).log(argThat((String s) -> s.contains("Before"))); + } + + @SneakyThrows + @Test + void beforeLogsAllPropsAndEvaluationContext() { + LoggingHook hook = new LoggingHook(true); + hook.before(hookContext, null); + + verify(logger).atDebug(); + verifyCommonProps(mockBuilder); + verify(mockBuilder).addKeyValue(contains(LoggingHook.EVALUATION_CONTEXT_KEY), any(EvaluationContext.class)); + verify(mockBuilder).log(argThat((String s) -> s.contains("Before"))); + } + + @SneakyThrows + @Test + void afterLogsAllPropsExceptEvaluationContext() { + LoggingHook hook = new LoggingHook(); + FlagEvaluationDetails details = FlagEvaluationDetails.builder().reason(REASON).variant(VARIANT).value(VALUE).build(); + hook.after(hookContext, details, null); + + verify(logger).atDebug(); + verifyAfterProps(mockBuilder); + verifyCommonProps(mockBuilder); + verify(mockBuilder, never()).addKeyValue(anyString(), any(EvaluationContext.class)); + verify(mockBuilder).log(argThat((String s) -> s.contains("After"))); + } + + @SneakyThrows + @Test + void afterLogsAllPropsAndEvaluationContext() { + LoggingHook hook = new LoggingHook(true); + FlagEvaluationDetails details = FlagEvaluationDetails.builder().reason(REASON).variant(VARIANT).value(VALUE).build(); + hook.after(hookContext, details, null); + + verify(logger).atDebug(); + verifyAfterProps(mockBuilder); + verifyCommonProps(mockBuilder); + verify(mockBuilder).addKeyValue(contains(LoggingHook.EVALUATION_CONTEXT_KEY), any(EvaluationContext.class)); + verify(mockBuilder).log(argThat((String s) -> s.contains("After"))); + } + + @SneakyThrows + @Test + void errorLogsAllPropsExceptEvaluationContext() { + LoggingHook hook = new LoggingHook(); + GeneralError error = new GeneralError(ERROR_MESSAGE); + hook.error(hookContext, error, null); + + verify(logger).atError(); + verifyCommonProps(mockBuilder); + verifyErrorProps(mockBuilder); + verify(mockBuilder, never()).addKeyValue(anyString(), any(EvaluationContext.class)); + verify(mockBuilder).log(argThat((String s) -> s.contains("Error")), any(Exception.class)); + } + + @SneakyThrows + @Test + void errorLogsAllPropsAndEvaluationContext() { + LoggingHook hook = new LoggingHook(true); + GeneralError error = new GeneralError(ERROR_MESSAGE); + hook.error(hookContext, error, null); + + verify(logger).atError(); + verifyCommonProps(mockBuilder); + verifyErrorProps(mockBuilder); + verify(mockBuilder).addKeyValue(contains(LoggingHook.EVALUATION_CONTEXT_KEY), any(EvaluationContext.class)); + verify(mockBuilder).log(argThat((String s) -> s.contains("Error")), any(Exception.class)); + } + + private void verifyCommonProps(LoggingEventBuilder mockBuilder) { + verify(mockBuilder).addKeyValue(LoggingHook.DOMAIN_KEY, DOMAIN); + verify(mockBuilder).addKeyValue(LoggingHook.FLAG_KEY_KEY, FLAG_KEY); + verify(mockBuilder).addKeyValue(LoggingHook.PROVIDER_NAME_KEY, PROVIDER_NAME); + verify(mockBuilder).addKeyValue(LoggingHook.DEFAULT_VALUE_KEY, DEFAULT_VALUE); + } + + private void verifyAfterProps(LoggingEventBuilder mockBuilder) { + verify(mockBuilder).addKeyValue(LoggingHook.REASON_KEY, REASON); + verify(mockBuilder).addKeyValue(LoggingHook.VARIANT_KEY, VARIANT); + verify(mockBuilder).addKeyValue(LoggingHook.VALUE_KEY, VALUE); + } + + private void verifyErrorProps(LoggingEventBuilder mockBuilder) { + verify(mockBuilder).addKeyValue(LoggingHook.ERROR_CODE_KEY, ERROR_CODE); + verify(mockBuilder).addKeyValue(LoggingHook.ERROR_MESSAGE_KEY, ERROR_MESSAGE); + } +} \ No newline at end of file