Add target_field parameter to ingest processors

docs/reference/ingest/ingest-node.asciidoc

@@ -1489,10 +1489,12 @@ If the field is not a string, the processor will throw an exception.
 .Gsub Options
 [options="header"]
 |======
-| Name          | Required  | Default  | Description
-| `field`       | yes       | -        | The field to apply the replacement to
-| `pattern`     | yes       | -        | The pattern to be replaced
-| `replacement` | yes       | -        | The string to replace the matching patterns with
+| Name              | Required  | Default  | Description
+| `field`           | yes       | -        | The field to apply the replacement to
+| `pattern`         | yes       | -        | The pattern to be replaced
+| `replacement`     | yes       | -        | The string to replace the matching patterns with
+| `target_field`    | no        | `field`  | The field to assign the converted value to, by default `field` is updated in-place
+| `ignore_missing`  | no        | `false`  | If `true` and `field` does not exist or is `null`, the processor quietly exits without modifying the document
 |======
 
 [source,js]
@@ -1516,9 +1518,10 @@ Throws an error when the field is not an array.
 .Join Options
 [options="header"]
 |======
-| Name          | Required  | Default  | Description
-| `field`       | yes       | -        | The field to be separated
-| `separator`   | yes       | -        | The separator character
+| Name              | Required  | Default  | Description
+| `field`           | yes       | -        | The field to be separated
+| `separator`       | yes       | -        | The separator character
+| `target_field`    | no        | `field`  | The field to assign the joined value to, by default `field` is updated in-place
 |======
 
 [source,js]
@@ -1662,6 +1665,7 @@ Converts a string to its lowercase equivalent.
 |======
 | Name             | Required  | Default  | Description
 | `field`          | yes       | -        | The field to make lowercase
+| `target_field`   | no        | `field`  | The field to assign the converted value to, by default `field` is updated in-place
 | `ignore_missing` | no        | `false`  | If `true` and `field` does not exist or is `null`, the processor quietly exits without modifying the document
 |======
 
@@ -1874,6 +1878,7 @@ Splits a field into an array using a separator character. Only works on string f
 | Name              | Required  | Default  | Description
 | `field`           | yes       | -        | The field to split
 | `separator`       | yes       | -        | A regex which matches the separator, eg `,` or `\s+`
+| `target_field`    | no        | `field`  | The field to assign the split value to, by default `field` is updated in-place
 | `ignore_missing`  | no        | `false`  | If `true` and `field` does not exist, the processor quietly exits without modifying the document
 |======
 
@@ -1899,9 +1904,10 @@ Throws an error when the field is not an array.
 .Sort Options
 [options="header"]
 |======
-| Name    | Required  | Default  | Description
-| `field` | yes       | -        | The field to be sorted
-| `order` | no        | `"asc"`  | The sort order to use. Accepts `"asc"` or `"desc"`.
+| Name              | Required  | Default  | Description
+| `field`           | yes       | -        | The field to be sorted
+| `order`           | no        | `"asc"`  | The sort order to use. Accepts `"asc"` or `"desc"`.
+| `target_field`    | no        | `field`  | The field to assign the sorted value to, by default `field` is updated in-place
 |======
 
 [source,js]
@@ -1927,6 +1933,7 @@ NOTE: This only works on leading and trailing whitespace.
 |======
 | Name              | Required  | Default  | Description
 | `field`           | yes       | -        | The string-valued field to trim whitespace from
+| `target_field`    | no        | `field`  | The field to assign the trimmed value to, by default `field` is updated in-place
 | `ignore_missing`  | no        | `false`  | If `true` and `field` does not exist, the processor quietly exits without modifying the document
 |======
 
@@ -1950,6 +1957,7 @@ Converts a string to its uppercase equivalent.
 |======
 | Name             | Required  | Default  | Description
 | `field`          | yes       | -        | The field to make uppercase
+| `target_field`   | no        | `field`  | The field to assign the converted value to, by default `field` is updated in-place
 | `ignore_missing` | no        | `false`  | If `true` and `field` does not exist or is `null`, the processor quietly exits without modifying the document
 |======
 

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/AbstractStringProcessor.java

@@ -33,11 +33,13 @@
 abstract class AbstractStringProcessor extends AbstractProcessor {
     private final String field;
     private final boolean ignoreMissing;
+    private final String targetField;
 
-    AbstractStringProcessor(String tag, String field, boolean ignoreMissing) {
+    AbstractStringProcessor(String tag, String field, boolean ignoreMissing, String targetField) {
         super(tag);
         this.field = field;
         this.ignoreMissing = ignoreMissing;
+        this.targetField = targetField;
     }
 
     public String getField() {
@@ -48,6 +50,10 @@ boolean isIgnoreMissing() {
         return ignoreMissing;
     }
 
+    String getTargetField() {
+        return targetField;
+    }
+
     @Override
     public final void execute(IngestDocument document) {
         String val = document.getFieldValue(field, String.class, ignoreMissing);
@@ -58,7 +64,7 @@ public final void execute(IngestDocument document) {
             throw new IllegalArgumentException("field [" + field + "] is null, cannot process it.");
         }
 
-        document.setFieldValue(field, process(val));
+        document.setFieldValue(targetField, process(val));
     }
 
     protected abstract String process(String value);
@@ -75,9 +81,12 @@ public AbstractStringProcessor create(Map<String, Processor.Factory> registry, S
                                               Map<String, Object> config) throws Exception {
             String field = ConfigurationUtils.readStringProperty(processorType, tag, config, "field");
             boolean ignoreMissing = ConfigurationUtils.readBooleanProperty(processorType, tag, config, "ignore_missing", false);
-            return newProcessor(tag, field, ignoreMissing);
+            String targetField = ConfigurationUtils.readStringProperty(processorType, tag, config, "target_field", field);
+
+            return newProcessor(tag, config, field, ignoreMissing, targetField);
         }
 
-        protected abstract AbstractStringProcessor newProcessor(String processorTag, String field, boolean ignoreMissing);
+        protected abstract AbstractStringProcessor newProcessor(String processorTag, Map<String, Object> config, String field,
+                                                                boolean ignoreMissing, String targetField);
     }
 }

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/GsubProcessor.java

@@ -19,12 +19,7 @@
 
 package org.elasticsearch.ingest.common;
 
-import org.elasticsearch.ingest.AbstractProcessor;
-import org.elasticsearch.ingest.IngestDocument;
-import org.elasticsearch.ingest.Processor;
-
 import java.util.Map;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import static org.elasticsearch.ingest.ConfigurationUtils.newConfigurationException;
@@ -34,25 +29,19 @@
  * Processor that allows to search for patterns in field content and replace them with corresponding string replacement.
  * Support fields of string type only, throws exception if a field is of a different type.
  */
-public final class GsubProcessor extends AbstractProcessor {
+public final class GsubProcessor extends AbstractStringProcessor {
 
     public static final String TYPE = "gsub";
 
-    private final String field;
     private final Pattern pattern;
     private final String replacement;
 
-    GsubProcessor(String tag, String field, Pattern pattern, String replacement) {
-        super(tag);
-        this.field = field;
+    GsubProcessor(String tag, String field, Pattern pattern, String replacement, boolean ignoreMissing, String targetField) {
+        super(tag, field, ignoreMissing, targetField);
         this.pattern = pattern;
         this.replacement = replacement;
     }
 
-    String getField() {
-        return field;
-    }
-
     Pattern getPattern() {
         return pattern;
     }
@@ -61,28 +50,25 @@ String getReplacement() {
         return replacement;
     }
 
-
     @Override
-    public void execute(IngestDocument document) {
-        String oldVal = document.getFieldValue(field, String.class);
-        if (oldVal == null) {
-            throw new IllegalArgumentException("field [" + field + "] is null, cannot match pattern.");
-        }
-        Matcher matcher = pattern.matcher(oldVal);
-        String newVal = matcher.replaceAll(replacement);
-        document.setFieldValue(field, newVal);
+    protected String process(String value) {
+        return pattern.matcher(value).replaceAll(replacement);
     }
 
     @Override
     public String getType() {
         return TYPE;
     }
 
-    public static final class Factory implements Processor.Factory {
+    public static final class Factory extends AbstractStringProcessor.Factory {
+
+        public Factory() {
+            super(TYPE);
+        }
+
         @Override
-        public GsubProcessor create(Map<String, Processor.Factory> registry, String processorTag,
-                                    Map<String, Object> config) throws Exception {
-            String field = readStringProperty(TYPE, processorTag, config, "field");
+        protected AbstractStringProcessor newProcessor(String processorTag, Map<String, Object> config, String field,
+                                                       boolean ignoreMissing, String targetField) {
             String pattern = readStringProperty(TYPE, processorTag, config, "pattern");
             String replacement = readStringProperty(TYPE, processorTag, config, "replacement");
             Pattern searchPattern;
@@ -91,7 +77,7 @@ public GsubProcessor create(Map<String, Processor.Factory> registry, String proc
             } catch (Exception e) {
                 throw newConfigurationException(TYPE, processorTag, "pattern", "Invalid regex pattern. " + e.getMessage());
             }
-            return new GsubProcessor(processorTag, field, searchPattern, replacement);
+            return new GsubProcessor(processorTag, field, searchPattern, replacement, ignoreMissing, targetField);
         }
     }
 }

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/JoinProcessor.java

@@ -38,11 +38,13 @@ public final class JoinProcessor extends AbstractProcessor {
 
     private final String field;
     private final String separator;
+    private final String targetField;
 
-    JoinProcessor(String tag, String field, String separator) {
+    JoinProcessor(String tag, String field, String separator, String targetField) {
         super(tag);
         this.field = field;
         this.separator = separator;
+        this.targetField = targetField;
     }
 
     String getField() {
@@ -53,6 +55,10 @@ String getSeparator() {
         return separator;
     }
 
+    String getTargetField() {
+        return targetField;
+    }
+
     @Override
     public void execute(IngestDocument document) {
         List<?> list = document.getFieldValue(field, List.class);
@@ -62,7 +68,7 @@ public void execute(IngestDocument document) {
         String joined = list.stream()
                 .map(Object::toString)
                 .collect(Collectors.joining(separator));
-        document.setFieldValue(field, joined);
+        document.setFieldValue(targetField, joined);
     }
 
     @Override
@@ -76,7 +82,8 @@ public JoinProcessor create(Map<String, Processor.Factory> registry, String proc
                                     Map<String, Object> config) throws Exception {
             String field = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "field");
             String separator = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "separator");
-            return new JoinProcessor(processorTag, field, separator);
+            String targetField = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "target_field", field);
+            return new JoinProcessor(processorTag, field, separator, targetField);
         }
     }
 }

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/LowercaseProcessor.java

@@ -20,6 +20,7 @@
 package org.elasticsearch.ingest.common;
 
 import java.util.Locale;
+import java.util.Map;
 
 /**
  * Processor that converts the content of string fields to lowercase.
@@ -30,8 +31,8 @@ public final class LowercaseProcessor extends AbstractStringProcessor {
 
     public static final String TYPE = "lowercase";
 
-    LowercaseProcessor(String processorTag, String field, boolean ignoreMissing) {
-        super(processorTag, field, ignoreMissing);
+    LowercaseProcessor(String processorTag, String field, boolean ignoreMissing, String targetField) {
+        super(processorTag, field, ignoreMissing, targetField);
     }
 
     @Override
@@ -51,8 +52,9 @@ public Factory() {
         }
 
         @Override
-        protected LowercaseProcessor newProcessor(String tag, String field, boolean ignoreMissing) {
-            return new LowercaseProcessor(tag, field, ignoreMissing);
+        protected LowercaseProcessor newProcessor(String tag, Map<String, Object> config, String field,
+                                                  boolean ignoreMissing, String targetField) {
+            return new LowercaseProcessor(tag, field, ignoreMissing, targetField);
         }
     }
 }

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/SortProcessor.java

@@ -69,11 +69,13 @@ public static SortOrder fromString(String value) {
 
     private final String field;
     private final SortOrder order;
+    private final String targetField;
 
-    SortProcessor(String tag, String field, SortOrder order) {
+    SortProcessor(String tag, String field, SortOrder order, String targetField) {
         super(tag);
         this.field = field;
         this.order = order;
+        this.targetField = targetField;
     }
 
     String getField() {
@@ -84,6 +86,10 @@ SortOrder getOrder() {
         return order;
     }
 
+    String getTargetField() {
+        return targetField;
+    }
+
     @Override
     @SuppressWarnings("unchecked")
     public void execute(IngestDocument document) {
@@ -103,7 +109,7 @@ public void execute(IngestDocument document) {
             Collections.sort(list, Collections.reverseOrder());
         }
 
-        document.setFieldValue(field, list);
+        document.setFieldValue(targetField, list);
     }
 
     @Override
@@ -117,6 +123,7 @@ public static final class Factory implements Processor.Factory {
         public SortProcessor create(Map<String, Processor.Factory> registry, String processorTag,
                                     Map<String, Object> config) throws Exception {
             String field = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, FIELD);
+            String targetField = ConfigurationUtils.readStringProperty(TYPE, processorTag, config, "target_field", field);
             try {
                 SortOrder direction = SortOrder.fromString(
                     ConfigurationUtils.readStringProperty(
@@ -125,7 +132,7 @@ public SortProcessor create(Map<String, Processor.Factory> registry, String proc
                         config,
                         ORDER,
                         DEFAULT_ORDER));
-                return new SortProcessor(processorTag, field, direction);
+                return new SortProcessor(processorTag, field, direction, targetField);
             } catch (IllegalArgumentException e) {
                 throw ConfigurationUtils.newConfigurationException(TYPE, processorTag, ORDER, e.getMessage());
             }