INGEST: Make a few Processors callable by Painless (#32170)

* INGEST: Make a few Processors callable by Painless
* Extracted a few stateless String processors as well as the json processor to static methods and whitelisted them in Painless
* provide whitelist from processors plugin

Author: original-brownbear

modules/ingest-common/build.gradle

@@ -20,11 +20,17 @@
 esplugin {
     description 'Module for ingest processors that do not require additional security permissions or have large dependencies and resources'
     classname 'org.elasticsearch.ingest.common.IngestCommonPlugin'
+    extendedPlugins = ['lang-painless']
 }
 
 dependencies {
+    compileOnly project(':modules:lang-painless')
     compile project(':libs:grok')
 }
 
 compileJava.options.compilerArgs << "-Xlint:-unchecked,-rawtypes"
 compileTestJava.options.compilerArgs << "-Xlint:-unchecked,-rawtypes"
+
+integTestCluster {
+    module project(':modules:lang-painless')
+}

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

@@ -35,9 +35,13 @@ public final class BytesProcessor extends AbstractStringProcessor {
         super(processorTag, field, ignoreMissing, targetField);
     }
 
+    public static long apply(String value) {
+        return ByteSizeValue.parseBytesSizeValue(value, null, "Ingest Field").getBytes();
+    }
+
     @Override
     protected Long process(String value) {
-        return ByteSizeValue.parseBytesSizeValue(value, null, getField()).getBytes();
+        return apply(value);
     }
 
     @Override

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

@@ -67,13 +67,11 @@ boolean isAddToRoot() {
         return addToRoot;
     }
 
-    @Override
-    public void execute(IngestDocument document) throws Exception {
-        Object fieldValue = document.getFieldValue(field, Object.class);
-        BytesReference bytesRef = (fieldValue == null) ? new BytesArray("null") : new BytesArray(fieldValue.toString());
+    public static Object apply(Object fieldValue) {
+        BytesReference bytesRef = fieldValue == null ? new BytesArray("null") : new BytesArray(fieldValue.toString());
         try (InputStream stream = bytesRef.streamInput();
              XContentParser parser = JsonXContent.jsonXContent
-                .createParser(NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, stream)) {
+                 .createParser(NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, stream)) {
             XContentParser.Token token = parser.nextToken();
             Object value = null;
             if (token == XContentParser.Token.VALUE_NULL) {
@@ -91,20 +89,32 @@ public void execute(IngestDocument document) throws Exception {
             } else if (token == XContentParser.Token.VALUE_EMBEDDED_OBJECT) {
                 throw new IllegalArgumentException("cannot read binary value");
             }
-            if (addToRoot && (value instanceof Map)) {
-                for (Map.Entry<String, Object> entry : ((Map<String, Object>) value).entrySet()) {
-                    document.setFieldValue(entry.getKey(), entry.getValue());
-                }
-            } else if (addToRoot) {
-                throw new IllegalArgumentException("cannot add non-map fields to root of document");
-            } else {
-                document.setFieldValue(targetField, value);
-            }
+            return value;
         } catch (IOException e) {
             throw new IllegalArgumentException(e);
         }
     }
 
+    public static void apply(Map<String, Object> ctx, String fieldName) {
+        Object value = apply(ctx.get(fieldName));
+        if (value instanceof Map) {
+            @SuppressWarnings("unchecked")
+                Map<String, Object> map = (Map<String, Object>) value;
+                ctx.putAll(map);
+        } else {
+            throw new IllegalArgumentException("cannot add non-map fields to root of document");
+        }
+    }
+
+    @Override
+    public void execute(IngestDocument document) throws Exception {
+        if (addToRoot) {
+           apply(document.getSourceAndMetadata(), field);
+        } else {
+            document.setFieldValue(targetField, apply(document.getFieldValue(field, Object.class)));
+        }
+    }
+
     @Override
     public String getType() {
         return TYPE;

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

@@ -35,9 +35,13 @@ public final class LowercaseProcessor extends AbstractStringProcessor {
         super(processorTag, field, ignoreMissing, targetField);
     }
 
+    public static String apply(String value) {
+        return value.toLowerCase(Locale.ROOT);
+    }
+
     @Override
     protected String process(String value) {
-        return value.toLowerCase(Locale.ROOT);
+        return apply(value);
     }
 
     @Override

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

@@ -0,0 +1,49 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.ingest.common;
+
+import java.util.Map;
+
+public final class Processors {
+
+    public static long bytes(String value) {
+        return BytesProcessor.apply(value);
+    }
+
+    public static String lowercase(String value) {
+        return LowercaseProcessor.apply(value);
+    }
+
+    public static String uppercase(String value) {
+        return UppercaseProcessor.apply(value);
+    }
+
+    public static Object json(Object fieldValue) {
+        return JsonProcessor.apply(fieldValue);
+    }
+
+    public static void json(Map<String, Object> ctx, String field) {
+        JsonProcessor.apply(ctx, field);
+    }
+
+    public static String urlDecode(String value) {
+        return URLDecodeProcessor.apply(value);
+    }
+}

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

@@ -0,0 +1,41 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.ingest.common;
+
+import org.elasticsearch.painless.spi.PainlessExtension;
+import org.elasticsearch.painless.spi.Whitelist;
+import org.elasticsearch.painless.spi.WhitelistLoader;
+import org.elasticsearch.script.IngestScript;
+import org.elasticsearch.script.ScriptContext;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+public class ProcessorsWhitelistExtension implements PainlessExtension {
+
+    private static final Whitelist WHITELIST =
+        WhitelistLoader.loadFromResourceFiles(ProcessorsWhitelistExtension.class, "processors_whitelist.txt");
+
+    @Override
+    public Map<ScriptContext<?>, List<Whitelist>> getContextWhitelists() {
+        return Collections.singletonMap(IngestScript.CONTEXT, Collections.singletonList(WHITELIST));
+    }
+}

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

@@ -34,15 +34,19 @@ public final class URLDecodeProcessor extends AbstractStringProcessor {
         super(processorTag, field, ignoreMissing, targetField);
     }
 
-    @Override
-    protected String process(String value) {
+    public static String apply(String value) {
         try {
             return URLDecoder.decode(value, "UTF-8");
         } catch (UnsupportedEncodingException e) {
-            throw new IllegalArgumentException("could not URL-decode field[" + getField() + "]", e);
+            throw new IllegalArgumentException("Could not URL-decode value.", e);
         }
     }
 
+    @Override
+    protected String process(String value) {
+        return apply(value);
+    }
+
     @Override
     public String getType() {
         return TYPE;

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

@@ -34,9 +34,13 @@ public final class UppercaseProcessor extends AbstractStringProcessor {
         super(processorTag, field, ignoreMissing, targetField);
     }
 
+    public static String apply(String value) {
+        return value.toUpperCase(Locale.ROOT);
+    }
+
     @Override
     protected String process(String value) {
-        return value.toUpperCase(Locale.ROOT);
+        return apply(value);
     }
 
     @Override

modules/ingest-common/src/main/resources/META-INF/services/org.elasticsearch.painless.spi.PainlessExtension

@@ -0,0 +1 @@
+org.elasticsearch.ingest.common.ProcessorsWhitelistExtension

modules/ingest-common/src/main/resources/org/elasticsearch/ingest/common/processors_whitelist.txt

@@ -0,0 +1,29 @@
+#
+# Licensed to Elasticsearch under one or more contributor
+# license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright
+# ownership. Elasticsearch licenses this file to you under
+# the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+# This file contains a whitelist of static processor methods that can be accessed from painless
+
+class org.elasticsearch.ingest.common.Processors {
+  long bytes(String)
+  String lowercase(String)
+  String uppercase(String)
+  Object json(Object)
+  void json(Map, String)
+  String urlDecode(String)
+}