Add sanitization for span attributes

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/CloudLoggingConfigurationCustomizerProvider.java

@@ -1,6 +1,7 @@
 package com.sap.hcf.cf.logging.opentelemetry.agent.ext;
 
 import com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding.CloudLoggingBindingPropertiesSupplier;
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.exporter.SanitizeSpanExporterCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
 
@@ -15,8 +16,7 @@ public class CloudLoggingConfigurationCustomizerProvider implements AutoConfigur
     public void customize(AutoConfigurationCustomizer autoConfiguration) {
         LOG.info("Initializing SAP BTP Observability extension " + VERSION);
         autoConfiguration.addPropertiesSupplier(new CloudLoggingBindingPropertiesSupplier());
-
-        // ConfigurableLogRecordExporterProvider
+        autoConfiguration.addSpanExporterCustomizer(new SanitizeSpanExporterCustomizer());
     }
 
 }

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/exporter/SanitizeSpanExporterCustomizer.java

@@ -0,0 +1,86 @@
+package com.sap.hcf.cf.logging.opentelemetry.agent.ext.exporter;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.common.AttributesBuilder;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.trace.data.DelegatingSpanData;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+
+import java.util.Collection;
+import java.util.function.BiFunction;
+import java.util.stream.Collectors;
+
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
+
+public class SanitizeSpanExporterCustomizer implements BiFunction<SpanExporter, ConfigProperties, SpanExporter> {
+
+    private static final String PROPERTY_ENABLED_KEY = "sap.cf.integration.otel.extension.sanitizer.enabled";
+    private static final AttributeKey<String> DB_QUERY_TEXT = stringKey("db.query.text");
+    //@Deprecated
+    private static final AttributeKey<String> DB_STATEMENT = stringKey("db.statement");
+
+    @Override
+    public SpanExporter apply(SpanExporter delegate, ConfigProperties config) {
+        if (config != null && !config.getBoolean(PROPERTY_ENABLED_KEY, true)) {
+            return delegate;
+        }
+        return new SpanExporter() {
+            @Override
+            public CompletableResultCode export(Collection<SpanData> spans) {
+                return delegate.export(spans.stream().map(this::sanitizeSpanData).collect(Collectors.toList()));
+            }
+
+            private SpanData sanitizeSpanData(SpanData spanData) {
+                Attributes attributes = spanData.getAttributes();
+                if (attributes == null) {
+                    return spanData;
+                }
+                String dbQueryText = attributes.get(DB_QUERY_TEXT);
+                String dbStatement = attributes.get(DB_STATEMENT);
+                if (isClean(dbQueryText) && isClean(dbStatement)) {
+                    return spanData;
+                }
+                AttributesBuilder sanitized = attributes.toBuilder();
+                if (!isClean(dbQueryText)) {
+                    sanitized.put(DB_QUERY_TEXT, dbQueryText.substring(0, 7) + " [REDACTED]");
+                }
+                if (!isClean(dbStatement)) {
+                    sanitized.put(DB_STATEMENT, dbStatement.substring(0, 7) + " [REDACTED]");
+                }
+                return new SanitizedSpanData(spanData, sanitized.build());
+            }
+
+            private boolean isClean(String query) {
+                return query == null || !query.toLowerCase().startsWith("connect");
+            }
+
+            @Override
+            public CompletableResultCode flush() {
+                return delegate.flush();
+            }
+
+            @Override
+            public CompletableResultCode shutdown() {
+                return delegate.shutdown();
+            }
+        };
+    }
+
+    private static class SanitizedSpanData extends DelegatingSpanData {
+
+        private final Attributes filteredAttributes;
+
+        protected SanitizedSpanData(SpanData delegate, Attributes filteredAttributes) {
+            super(delegate);
+            this.filteredAttributes = filteredAttributes;
+        }
+
+        @Override
+        public Attributes getAttributes() {
+            return filteredAttributes;
+        }
+    }
+}

cf-java-logging-support-opentelemetry-agent-extension/src/test/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/exporter/SanitizeSpanExporterCustomizerTest.java

@@ -0,0 +1,150 @@
+package com.sap.hcf.cf.logging.opentelemetry.agent.ext.exporter;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class SanitizeSpanExporterCustomizerTest {
+
+    @Mock(strictness = Mock.Strictness.LENIENT)
+    private SpanData spanData;
+
+    @Mock
+    private SpanExporter delegateExporter;
+
+    @Captor
+    private ArgumentCaptor<List<SpanData>> spanDataCaptor;
+
+    private SpanExporter sanitizeExporter;
+
+    @BeforeEach
+    void setUp() {
+        when(spanData.getName()).thenReturn("test-span");
+        this.sanitizeExporter = new SanitizeSpanExporterCustomizer().apply(delegateExporter, null);
+    }
+
+    @Test
+    void forwardsSpanWithoutAttributes() {
+        List<SpanData> spans = List.of(spanData);
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spans);
+    }
+
+    @Test
+    void forwardsSpanWithEmptyAttributes() {
+        List<SpanData> spans = List.of(spanData);
+        when(spanData.getAttributes()).thenReturn(Attributes.empty());
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spans);
+    }
+
+    @Test
+    void forwardsSpanWithoutSensitiveAttributeKey() {
+        Attributes attributes = Attributes.builder().put("some.key", "some value").build();
+        when(spanData.getAttributes()).thenReturn(attributes);
+        List<SpanData> spans = List.of(spanData);
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spans);
+    }
+
+    @Test
+    void forwardsSpanWithSensitiveAttributeKeyButWithoutSensitiveValue() {
+        Attributes attributes = Attributes.builder().put("db.query.text", "some safe value").build();
+        when(spanData.getAttributes()).thenReturn(attributes);
+        List<SpanData> spans = List.of(spanData);
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spans);
+    }
+
+    @Test
+    void redactsSensitiveDbQueryTextValue() {
+        Attributes attributes = Attributes.builder().put("db.query.text", "Connect somewhere").build();
+        when(spanData.getAttributes()).thenReturn(attributes);
+        List<SpanData> spans = List.of(spanData);
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spanDataCaptor.capture());
+        SpanData sanitizedSpan = spanDataCaptor.getValue().get(0);
+        assertThat(sanitizedSpan).extracting(SpanData::getName).isEqualTo("test-span");
+        assertThat(sanitizedSpan).extracting(SpanData::getAttributes)
+                                 .extracting(attrs -> attrs.get(AttributeKey.stringKey("db.query.text")))
+                                 .isEqualTo("Connect [REDACTED]");
+    }
+
+    @Test
+    void redactsSensitiveDbStatementValue() {
+        Attributes attributes = Attributes.builder().put("db.statement", "CONNECT somewhere").build();
+        when(spanData.getAttributes()).thenReturn(attributes);
+        List<SpanData> spans = List.of(spanData);
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spanDataCaptor.capture());
+        SpanData sanitizedSpan = spanDataCaptor.getValue().get(0);
+        assertThat(sanitizedSpan).extracting(SpanData::getName).isEqualTo("test-span");
+        assertThat(sanitizedSpan).extracting(SpanData::getAttributes)
+                                 .extracting(attrs -> attrs.get(AttributeKey.stringKey("db.statement")))
+                                 .isEqualTo("CONNECT [REDACTED]");
+    }
+
+    @Test
+    void keepsOtherAttributesOnRedaction() {
+        Attributes attributes =
+                Attributes.builder().put("db.query.text", "connect somewhere").put("some.key", "some.value").build();
+        when(spanData.getAttributes()).thenReturn(attributes);
+        List<SpanData> spans = List.of(spanData);
+        sanitizeExporter.export(spans);
+
+        verify(delegateExporter).export(spanDataCaptor.capture());
+        SpanData sanitizedSpan = spanDataCaptor.getValue().get(0);
+        assertThat(sanitizedSpan).extracting(SpanData::getName).isEqualTo("test-span");
+        assertThat(sanitizedSpan).extracting(SpanData::getAttributes)
+                                 .extracting(attrs -> attrs.get(AttributeKey.stringKey("db.query.text")))
+                                 .isEqualTo("connect [REDACTED]");
+        assertThat(sanitizedSpan).extracting(SpanData::getAttributes)
+                                 .extracting(attrs -> attrs.get(AttributeKey.stringKey("some.key")))
+                                 .isEqualTo("some.value");
+    }
+
+    @Test
+    void canBeDisabledViaConfig() {
+        Map<String, String> configEntries = new HashMap<>();
+        configEntries.put("sap.cf.integration.otel.extension.sanitizer.enabled", "false");
+        DefaultConfigProperties configProperties = DefaultConfigProperties.createFromMap(configEntries);
+        SpanExporter spanExporter = new SanitizeSpanExporterCustomizer().apply(delegateExporter, configProperties);
+        assertThat(spanExporter).isSameAs(delegateExporter);
+    }
+
+    @Test
+    void delegatesFlush() {
+        sanitizeExporter.flush();
+        verify(delegateExporter).flush();
+    }
+
+    @Test
+    void delegatesShutdown() {
+        sanitizeExporter.shutdown();
+        verify(delegateExporter).shutdown();
+    }
+}