Add copy ingest processor (#11870)

---------

Signed-off-by: Gao Binlong <[email protected]>

CHANGELOG.md

@@ -126,6 +126,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add additional handling in SearchTemplateRequest when simulate is set to true ([#11591](https://github.com/opensearch-project/OpenSearch/pull/11591))
 - Introduce cluster level setting `cluster.index.restrict.replication.type` to prevent replication type setting override during index creations([#11583](https://github.com/opensearch-project/OpenSearch/pull/11583))
 - Add match_only_text field that is optimized for storage by trading off positional queries performance ([#6836](https://github.com/opensearch-project/OpenSearch/pull/11039))
+- Add copy ingest processor ([#11870](https://github.com/opensearch-project/OpenSearch/pull/11870))
 - Introduce new feature flag "WRITEABLE_REMOTE_INDEX" to gate the writeable remote index functionality ([#11717](https://github.com/opensearch-project/OpenSearch/pull/11170))
 - Bump OpenTelemetry from 1.32.0 to 1.34.1 ([#11891](https://github.com/opensearch-project/OpenSearch/pull/11891))
 

modules/ingest-common/src/main/java/org/opensearch/ingest/common/CopyProcessor.java

@@ -0,0 +1,161 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ingest.common;
+
+import org.opensearch.core.common.Strings;
+import org.opensearch.ingest.AbstractProcessor;
+import org.opensearch.ingest.ConfigurationUtils;
+import org.opensearch.ingest.IngestDocument;
+import org.opensearch.ingest.Processor;
+import org.opensearch.script.ScriptService;
+import org.opensearch.script.TemplateScript;
+
+import java.util.Map;
+
+public final class CopyProcessor extends AbstractProcessor {
+    public static final String TYPE = "copy";
+
+    private final TemplateScript.Factory sourceField;
+    private final TemplateScript.Factory targetField;
+
+    private final boolean ignoreMissing;
+
+    private final boolean removeSource;
+
+    private final boolean overrideTarget;
+
+    CopyProcessor(String tag, String description, TemplateScript.Factory sourceField, TemplateScript.Factory targetField) {
+        this(tag, description, sourceField, targetField, false, false, false);
+    }
+
+    CopyProcessor(
+        String tag,
+        String description,
+        TemplateScript.Factory sourceField,
+        TemplateScript.Factory targetField,
+        boolean ignoreMissing,
+        boolean removeSource,
+        boolean overrideTarget
+    ) {
+        super(tag, description);
+        this.sourceField = sourceField;
+        this.targetField = targetField;
+        this.ignoreMissing = ignoreMissing;
+        this.removeSource = removeSource;
+        this.overrideTarget = overrideTarget;
+    }
+
+    public TemplateScript.Factory getSourceField() {
+        return sourceField;
+    }
+
+    public TemplateScript.Factory getTargetField() {
+        return targetField;
+    }
+
+    public boolean isIgnoreMissing() {
+        return ignoreMissing;
+    }
+
+    public boolean isRemoveSource() {
+        return removeSource;
+    }
+
+    public boolean isOverrideTarget() {
+        return overrideTarget;
+    }
+
+    @Override
+    public IngestDocument execute(IngestDocument document) {
+        String source = document.renderTemplate(sourceField);
+        final boolean sourceFieldPathIsNullOrEmpty = Strings.isNullOrEmpty(source);
+        if (sourceFieldPathIsNullOrEmpty || document.hasField(source, true) == false) {
+            if (ignoreMissing) {
+                return document;
+            } else if (sourceFieldPathIsNullOrEmpty) {
+                throw new IllegalArgumentException("source field path cannot be null nor empty");
+            } else {
+                throw new IllegalArgumentException("source field [" + source + "] doesn't exist");
+            }
+        }
+
+        String target = document.renderTemplate(targetField);
+        if (Strings.isNullOrEmpty(target)) {
+            throw new IllegalArgumentException("target field path cannot be null nor empty");
+        }
+        if (source.equals(target)) {
+            throw new IllegalArgumentException("source field path and target field path cannot be same");
+        }
+
+        if (overrideTarget || document.hasField(target, true) == false || document.getFieldValue(target, Object.class) == null) {
+            Object sourceValue = document.getFieldValue(source, Object.class);
+            document.setFieldValue(target, IngestDocument.deepCopy(sourceValue));
+        } else {
+            throw new IllegalArgumentException("target field [" + target + "] already exists");
+        }
+
+        if (removeSource) {
+            document.removeField(source);
+        }
+
+        return document;
+    }
+
+    @Override
+    public String getType() {
+        return TYPE;
+    }
+
+    public static final class Factory implements Processor.Factory {
+
+        private final ScriptService scriptService;
+
+        public Factory(ScriptService scriptService) {
+            this.scriptService = scriptService;
+        }
+
+        @Override
+        public CopyProcessor create(
+            Map<String, Processor.Factory> registry,
+            String processorTag,
+            String description,
+            Map<String, Object> config
+        ) throws Exception {
+            String sourceField = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "source_field");
+            TemplateScript.Factory sourceFieldTemplate = ConfigurationUtils.compileTemplate(
+                TYPE,
+                processorTag,
+                "source_field",
+                sourceField,
+                scriptService
+            );
+            String targetField = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "target_field");
+            TemplateScript.Factory targetFieldTemplate = ConfigurationUtils.compileTemplate(
+                TYPE,
+                processorTag,
+                "target_field",
+                targetField,
+                scriptService
+            );
+            boolean ignoreMissing = ConfigurationUtils.readBooleanProperty(TYPE, processorTag, config, "ignore_missing", false);
+            boolean removeSource = ConfigurationUtils.readBooleanProperty(TYPE, processorTag, config, "remove_source", false);
+            boolean overrideTarget = ConfigurationUtils.readBooleanProperty(TYPE, processorTag, config, "override_target", false);
+
+            return new CopyProcessor(
+                processorTag,
+                description,
+                sourceFieldTemplate,
+                targetFieldTemplate,
+                ignoreMissing,
+                removeSource,
+                overrideTarget
+            );
+        }
+    }
+}

modules/ingest-common/src/main/java/org/opensearch/ingest/common/IngestCommonModulePlugin.java

@@ -106,6 +106,7 @@ public Map<String, Processor.Factory> getProcessors(Processor.Parameters paramet
         processors.put(DropProcessor.TYPE, new DropProcessor.Factory());
         processors.put(HtmlStripProcessor.TYPE, new HtmlStripProcessor.Factory());
         processors.put(CsvProcessor.TYPE, new CsvProcessor.Factory());
+        processors.put(CopyProcessor.TYPE, new CopyProcessor.Factory(parameters.scriptService));
         return Collections.unmodifiableMap(processors);
     }
 

modules/ingest-common/src/test/java/org/opensearch/ingest/common/CopyProcessorFactoryTests.java

@@ -0,0 +1,101 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.ingest.common;
+
+import org.opensearch.OpenSearchException;
+import org.opensearch.OpenSearchParseException;
+import org.opensearch.ingest.TestTemplateService;
+import org.opensearch.test.OpenSearchTestCase;
+import org.junit.Before;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+
+public class CopyProcessorFactoryTests extends OpenSearchTestCase {
+
+    private CopyProcessor.Factory factory;
+
+    @Before
+    public void init() {
+        factory = new CopyProcessor.Factory(TestTemplateService.instance());
+    }
+
+    public void testCreate() throws Exception {
+        boolean ignoreMissing = randomBoolean();
+        boolean removeSource = randomBoolean();
+        boolean overrideTarget = randomBoolean();
+        Map<String, Object> config = new HashMap<>();
+        config.put("source_field", "source");
+        config.put("target_field", "target");
+        config.put("ignore_missing", ignoreMissing);
+        config.put("remove_source", removeSource);
+        config.put("override_target", overrideTarget);
+        String processorTag = randomAlphaOfLength(10);
+        CopyProcessor copyProcessor = factory.create(null, processorTag, null, config);
+        assertThat(copyProcessor.getTag(), equalTo(processorTag));
+        assertThat(copyProcessor.getSourceField().newInstance(Collections.emptyMap()).execute(), equalTo("source"));
+        assertThat(copyProcessor.getTargetField().newInstance(Collections.emptyMap()).execute(), equalTo("target"));
+        assertThat(copyProcessor.isIgnoreMissing(), equalTo(ignoreMissing));
+        assertThat(copyProcessor.isRemoveSource(), equalTo(removeSource));
+        assertThat(copyProcessor.isOverrideTarget(), equalTo(overrideTarget));
+    }
+
+    public void testCreateWithSourceField() throws Exception {
+        Map<String, Object> config = new HashMap<>();
+        try {
+            factory.create(null, null, null, config);
+            fail("factory create should have failed");
+        } catch (OpenSearchParseException e) {
+            assertThat(e.getMessage(), equalTo("[source_field] required property is missing"));
+        }
+
+        config.put("source_field", null);
+        try {
+            factory.create(null, null, null, config);
+            fail("factory create should have failed");
+        } catch (OpenSearchParseException e) {
+            assertThat(e.getMessage(), equalTo("[source_field] required property is missing"));
+        }
+    }
+
+    public void testCreateWithTargetField() throws Exception {
+        Map<String, Object> config = new HashMap<>();
+        config.put("source_field", "source");
+        try {
+            factory.create(null, null, null, config);
+            fail("factory create should have failed");
+        } catch (OpenSearchParseException e) {
+            assertThat(e.getMessage(), equalTo("[target_field] required property is missing"));
+        }
+
+        config.put("source_field", "source");
+        config.put("target_field", null);
+        try {
+            factory.create(null, null, null, config);
+            fail("factory create should have failed");
+        } catch (OpenSearchParseException e) {
+            assertThat(e.getMessage(), equalTo("[target_field] required property is missing"));
+        }
+    }
+
+    public void testInvalidMustacheTemplate() throws Exception {
+        CopyProcessor.Factory factory = new CopyProcessor.Factory(TestTemplateService.instance(true));
+        Map<String, Object> config = new HashMap<>();
+        config.put("source_field", "{{source}}");
+        config.put("target_field", "target");
+        String processorTag = randomAlphaOfLength(10);
+        OpenSearchException exception = expectThrows(OpenSearchException.class, () -> factory.create(null, processorTag, null, config));
+        assertThat(exception.getMessage(), equalTo("java.lang.RuntimeException: could not compile script"));
+        assertThat(exception.getMetadata("opensearch.processor_tag").get(0), equalTo(processorTag));
+    }
+
+}