#7273 ingest to logstash DSL migration: gsub

Fixes #7311

tools/ingest-converter/src/main/java/org/logstash/ingest/Gsub.java

@@ -0,0 +1,30 @@
+package org.logstash.ingest;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptException;
+
+public final class Gsub {
+
+    private Gsub() {
+        // Utility Wrapper for JS Script.
+    }
+    
+    public static void main(final String... args) throws ScriptException, NoSuchMethodException {
+        try {
+            final ScriptEngine engine = JsUtil.engine();
+            Files.write(Paths.get(args[1]), ((String) ((Invocable) engine).invokeFunction(
+                "ingest_to_logstash_gsub",
+                new String(
+                    Files.readAllBytes(Paths.get(args[0])), StandardCharsets.UTF_8
+                )
+            )).getBytes(StandardCharsets.UTF_8));
+        } catch (final IOException ex) {
+            throw new IllegalStateException(ex);
+        }
+    }
+}

tools/ingest-converter/src/main/java/org/logstash/ingest/JsUtil.java

@@ -12,7 +12,9 @@ final class JsUtil {
     /**
      * Script names used by the converter in correct load order.
      */
-    private static final String[] SCRIPTS = {"shared", "date", "grok", "geoip", "pipeline", "convert"};
+
+    private static final String[] SCRIPTS =
+        {"shared", "date", "grok", "geoip", "gsub", "pipeline", "convert"};
 
     private JsUtil() {
         // Utility Class

tools/ingest-converter/src/main/resources/ingest-gsub.js

@@ -0,0 +1,29 @@
+var IngestGsub = {
+    has_gsub: function (processor) {
+        return !!processor["gsub"];
+    },
+    gsub_hash: function (processor) {
+        var gsub_data = processor["gsub"];
+        return IngestConverter.create_field(
+            "gsub",
+            "[\n" + [IngestConverter.dots_to_square_brackets(gsub_data["field"]),
+                gsub_data["pattern"], gsub_data["replacement"]].map(IngestConverter.quote_string)
+                .join(", ") + "\n]"
+        );
+    }
+};
+
+/**
+ * Converts Ingest JSON to LS Grok.
+ */
+function ingest_to_logstash_gsub(json) {
+
+    function map_processor(processor) {
+
+        return IngestConverter.filter_hash(
+            IngestConverter.create_hash("mutate", IngestGsub.gsub_hash(processor))
+        )
+    }
+
+    return IngestConverter.filters_to_file(JSON.parse(json)["processors"].map(map_processor));
+}

tools/ingest-converter/src/main/resources/ingest-pipeline.js

@@ -24,7 +24,12 @@ function ingest_pipeline_to_logstash(json) {
         if (IngestConvert.has_convert(processor)) {
             filter_blocks.push(
                 IngestConverter.create_hash("mutate", IngestConvert.convert_hash(processor))
-            )
+            );
+        }
+        if (IngestGsub.has_gsub(processor)) {
+            filter_blocks.push(
+                IngestConverter.create_hash("mutate", IngestGsub.gsub_hash(processor))
+            );
         }
         return IngestConverter.join_hash_fields(filter_blocks);
     }

tools/ingest-converter/src/test/java/org/logstash/ingest/GsubTest.java

@@ -0,0 +1,25 @@
+package org.logstash.ingest;
+
+import java.util.Collections;
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.runners.Parameterized.Parameters;
+
+public final class GsubTest extends IngestTest {
+
+    @Parameters
+    public static Iterable<String> data() {
+        return Collections.singletonList("GsubSimple");
+    }
+
+    @Test
+    public void convertsGsubCorrectly() throws Exception {
+        final String date = getResultPath(temp);
+        Gsub.main(resourcePath(String.format("ingest%s.json", testCase)), date);
+        assertThat(
+            utf8File(date), is(utf8File(resourcePath(String.format("logstash%s.conf", testCase))))
+        );
+    }
+}

tools/ingest-converter/src/test/java/org/logstash/ingest/PipelineTest.java

@@ -19,6 +19,7 @@ public final class PipelineTest extends IngestTest {
         DateTest.data().forEach(cases::add);
         GrokTest.data().forEach(cases::add);
         ConvertTest.data().forEach(cases::add);
+        GsubTest.data().forEach(cases::add);
         return cases;
     }
 

tools/ingest-converter/src/test/resources/org/logstash/ingest/ingestGsubSimple.json

@@ -0,0 +1,12 @@
+{
+  "description": "ExampleGsub",
+  "processors": [
+    {
+      "gsub": {
+        "field": "field1",
+        "pattern": "\\.",
+        "replacement": "_"
+      }
+    }
+  ]
+}

tools/ingest-converter/src/test/resources/org/logstash/ingest/logstashGsubSimple.conf

@@ -0,0 +1,7 @@
+filter {
+   mutate {
+      gsub => [
+         "field1", "\.", "_"
+      ]
+   }
+}