Fix timezone fallback in ingest processor (#38407)

If no timezone was specified in the date processor, then the conversion
would lead to wrong time, as UTC was assumed by default, leading to
incorrectly parsed dates.

This commit does not assume a default timezone and will thus not format
the dates in a wrong way.

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

@@ -87,10 +87,16 @@ enum DateFormat {
                 format = format.substring(1);
             }
 
+            boolean isUtc = ZoneOffset.UTC.equals(zoneId);
+
             int year = LocalDate.now(ZoneOffset.UTC).getYear();
-            DateFormatter formatter = DateFormatter.forPattern(format)
-                .withLocale(locale)
-                .withZone(zoneId);
+            DateFormatter dateFormatter = DateFormatter.forPattern(format)
+                .withLocale(locale);
+            // if UTC zone is set here, the the time zone specified in the format will be ignored, leading to wrong dates
+            if (isUtc == false) {
+                dateFormatter = dateFormatter.withZone(zoneId);
+            }
+            final DateFormatter formatter = dateFormatter;
             return text -> {
                 TemporalAccessor accessor = formatter.parse(text);
                 // if there is no year, we fall back to the current one and
@@ -106,7 +112,11 @@ enum DateFormat {
                     accessor = newTime.withZoneSameLocal(zoneId);
                 }
 
-                return DateFormatters.from(accessor);
+                if (isUtc) {
+                    return DateFormatters.from(accessor).withZoneSameInstant(ZoneOffset.UTC);
+                } else {
+                    return DateFormatters.from(accessor);
+                }
             };
         }
     };

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

@@ -43,7 +43,7 @@ public final class DateProcessor extends AbstractProcessor {
 
     public static final String TYPE = "date";
     static final String DEFAULT_TARGET_FIELD = "@timestamp";
-    public static final DateFormatter FORMATTER = DateFormatter.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
+    private static final DateFormatter FORMATTER = DateFormatter.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
 
     private final TemplateScript.Factory timezone;
     private final TemplateScript.Factory locale;

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/DateFormatTests.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.ingest.common;
 
+import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.common.time.DateUtils;
 import org.elasticsearch.test.ESTestCase;
 
@@ -43,6 +44,14 @@ public class DateFormatTests extends ESTestCase {
                 equalTo("11 24 01:29:01"));
     }
 
+    public void testParseJavaWithTimeZone() {
+        Function<String, ZonedDateTime> javaFunction = DateFormat.Java.getFunction("yyyy-MM-dd'T'HH:mm:ss.SSSZZ",
+            ZoneOffset.UTC, Locale.ROOT);
+        ZonedDateTime datetime = javaFunction.apply("2018-02-05T13:44:56.657+0100");
+        String expectedDateTime = DateFormatter.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSSXXX").withZone(ZoneOffset.UTC).format(datetime);
+        assertThat(expectedDateTime, is("2018-02-05T12:44:56.657Z"));
+    }
+
     public void testParseJavaDefaultYear() {
         String format = randomFrom("8dd/MM", "dd/MM");
         ZoneId timezone = DateUtils.of("Europe/Amsterdam");
@@ -70,6 +79,10 @@ public class DateFormatTests extends ESTestCase {
     public void testParseISO8601() {
         assertThat(DateFormat.Iso8601.getFunction(null, ZoneOffset.UTC, null).apply("2001-01-01T00:00:00-0800").toInstant().toEpochMilli(),
                 equalTo(978336000000L));
+        assertThat(DateFormat.Iso8601.getFunction(null, ZoneOffset.UTC, null).apply("2001-01-01T00:00:00-0800").toString(),
+                equalTo("2001-01-01T08:00Z"));
+        assertThat(DateFormat.Iso8601.getFunction(null, ZoneOffset.UTC, null).apply("2001-01-01T00:00:00-0800").toString(),
+                equalTo("2001-01-01T08:00Z"));
     }
 
     public void testParseISO8601Failure() {

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/DateProcessorTests.java

@@ -29,6 +29,7 @@ import java.time.ZoneId;
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -97,6 +98,18 @@ public class DateProcessorTests extends ESTestCase {
         }
     }
 
+    public void testJavaPatternNoTimezone() {
+        DateProcessor dateProcessor = new DateProcessor(randomAlphaOfLength(10),
+            null, null,
+            "date_as_string", Arrays.asList("yyyy dd MM HH:mm:ss XXX"), "date_as_date");
+
+        Map<String, Object> document = new HashMap<>();
+        document.put("date_as_string", "2010 12 06 00:00:00 -02:00");
+        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), document);
+        dateProcessor.execute(ingestDocument);
+        assertThat(ingestDocument.getFieldValue("date_as_date", String.class), equalTo("2010-06-12T02:00:00.000Z"));
+    }
+
     public void testInvalidJavaPattern() {
         try {
             DateProcessor processor = new DateProcessor(randomAlphaOfLength(10),

modules/ingest-common/src/test/resources/rest-api-spec/test/ingest/30_date_processor.yml

@@ -39,3 +39,94 @@ teardown:
         id: 1
   - match: { _source.date_source_field: "12/06/2010" }
   - match: { _source.date_target_field: "2010-06-12T00:00:00.000+02:00" }
+
+---
+"Test date processor with no timezone configured":
+
+  - do:
+      ingest.put_pipeline:
+        id: "my_pipeline"
+        # sample formats from beats, featuring mongodb, icinga, apache
+        body:  >
+          {
+            "description": "_description",
+            "processors": [
+              {
+                "date" : {
+                  "field" : "date_source_1",
+                  "target_field" : "date_target_1",
+                  "formats" : ["yyyy-MM-dd'T'HH:mm:ss.SSSZZ" ]
+                }
+              },
+              {
+                "date" : {
+                  "field" : "date_source_2",
+                  "target_field" : "date_target_2",
+                  "formats" : ["yyyy-MM-dd HH:mm:ss Z" ]
+                }
+              },
+              {
+                "date" : {
+                  "field" : "date_source_3",
+                  "target_field" : "date_target_3",
+                  "formats" : [ "dd/MMM/yyyy:H:m:s Z" ]
+                }
+              },
+              {
+                "date" : {
+                  "field" : "date_source_4",
+                  "target_field" : "date_target_4",
+                  "formats" : [ "UNIX" ]
+                }
+              },
+              {
+                "date" : {
+                  "field" : "date_source_5",
+                  "target_field" : "date_target_5",
+                  "formats" : [ "UNIX_MS" ]
+                }
+              },
+              {
+                "date" : {
+                  "field" : "date_source_6",
+                  "target_field" : "date_target_6",
+                  "formats" : [ "TAI64N" ]
+                }
+              },
+              {
+                "date" : {
+                  "field" : "date_source_7",
+                  "target_field" : "date_target_7",
+                  "formats" : [ "ISO8601" ]
+                }
+              }
+            ]
+          }
+  - match: { acknowledged: true }
+
+  - do:
+      index:
+        index: test
+        id: 1
+        pipeline: "my_pipeline"
+        body: { date_source_1: "2018-02-05T13:44:56.657+0100", date_source_2: "2017-04-04 13:43:09 +0200", date_source_3: "10/Aug/2018:09:45:56 +0200", date_source_4: "1", date_source_5: "1", date_source_6: "4000000050d506482dbdf024", date_source_7: "2018-02-05T13:44:56.657+0100" }
+
+  - do:
+      get:
+        index: test
+        id: 1
+  - match: { _source.date_source_1: "2018-02-05T13:44:56.657+0100" }
+  - match: { _source.date_target_1: "2018-02-05T12:44:56.657Z" }
+  - match: { _source.date_source_2: "2017-04-04 13:43:09 +0200" }
+  - match: { _source.date_target_2: "2017-04-04T11:43:09.000Z" }
+  - match: { _source.date_source_3: "10/Aug/2018:09:45:56 +0200" }
+  - match: { _source.date_target_3: "2018-08-10T07:45:56.000Z" }
+  - match: { _source.date_source_4: "1" }
+  - match: { _source.date_target_4: "1970-01-01T00:00:01.000Z" }
+  - match: { _source.date_source_5: "1" }
+  - match: { _source.date_target_5: "1970-01-01T00:00:00.001Z" }
+  - match: { _source.date_source_6: "4000000050d506482dbdf024" }
+  - match: { _source.date_target_6: "2012-12-22T01:00:46.767Z" }
+  - match: { _source.date_source_7: "2018-02-05T13:44:56.657+0100" }
+  - match: { _source.date_target_7: "2018-02-05T12:44:56.657Z" }
+