Github user markap14 commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1652#discussion_r110646007
--- Diff:
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/grok/GrokReader.java
---
@@ -0,0 +1,111 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.nifi.grok;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.nifi.annotation.documentation.CapabilityDescription;
+import org.apache.nifi.annotation.documentation.Tags;
+import org.apache.nifi.annotation.lifecycle.OnEnabled;
+import org.apache.nifi.components.PropertyDescriptor;
+import org.apache.nifi.controller.ConfigurationContext;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ComponentLog;
+import org.apache.nifi.processor.util.StandardValidators;
+import org.apache.nifi.serialization.RecordReader;
+import org.apache.nifi.serialization.RowRecordReaderFactory;
+import org.apache.nifi.serialization.SchemaRegistryRecordReader;
+import org.apache.nifi.serialization.record.RecordSchema;
+
+import io.thekraken.grok.api.Grok;
+import io.thekraken.grok.api.exception.GrokException;
+
+@Tags({"grok", "logs", "logfiles", "parse", "unstructured", "text",
"record", "reader", "regex", "pattern", "logstash"})
+@CapabilityDescription("Provides a mechanism for reading unstructured text
data, such as log files, and structuring the data "
+ + "so that it can be processed. The service is configured using Grok
patterns. "
+ + "The service reads from a stream of data and splits each message
that it finds into a separate Record, each containing the fields that are
configured. "
+ + "If a line in the input does not match the expected message pattern,
the line of text is considered to be part of the previous "
+ + "message, with the exception of stack traces. A stack trace that is
found at the end of a log message is considered to be part "
+ + "of the previous message but is added to the 'STACK_TRACE' field of
the Record. If a record has no stack trace, it will have a NULL value "
+ + "for the STACK_TRACE field. All fields that are parsed are
considered to be of type String by default. If there is need to change the type
of a field, "
+ + "this can be accomplished by configuring the Schema Registry to use
and adding the appropriate schema.")
+public class GrokReader extends SchemaRegistryRecordReader implements
RowRecordReaderFactory {
+ private volatile Grok grok;
+ private volatile boolean useSchemaRegistry;
+
+ private static final String DEFAULT_PATTERN_NAME =
"/default-grok-patterns.txt";
+
+ static final PropertyDescriptor PATTERN_FILE = new
PropertyDescriptor.Builder()
+ .name("Grok Pattern File")
+ .description("Path to a file that contains Grok Patterns to use
for parsing logs. If not specified, a built-in default Pattern file "
+ + "will be used. If specified, all patterns in the given
pattern file will override the default patterns. See the Controller Service's "
+ + "Additional Details for a list of pre-defined patterns.")
+ .addValidator(StandardValidators.FILE_EXISTS_VALIDATOR)
+ .expressionLanguageSupported(true)
+ .required(false)
+ .build();
+
+ static final PropertyDescriptor GROK_EXPRESSION = new
PropertyDescriptor.Builder()
+ .name("Grok Expression")
+ .description("Specifies the format of a log line in Grok format.
This allows the Record Reader to understand how to parse each log line. "
+ + "If a line in the log file does not match this pattern, the
line will be assumed to belong to the previous log message.")
+ .addValidator(new GrokExpressionValidator())
+ .required(true)
+ .build();
+
+ @Override
+ protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
+ final List<PropertyDescriptor> properties = new
ArrayList<>(super.getSupportedPropertyDescriptors());
+ properties.add(PATTERN_FILE);
+ properties.add(GROK_EXPRESSION);
+ return properties;
+ }
+
+ @OnEnabled
+ public void preCompile(final ConfigurationContext context) throws
GrokException, IOException {
+ grok = new Grok();
+
+ try (final InputStream in =
getClass().getResourceAsStream(DEFAULT_PATTERN_NAME);
+ final Reader reader = new InputStreamReader(in)) {
+ grok.addPatternFromReader(reader);
+ }
+
+ if (context.getProperty(PATTERN_FILE).isSet()) {
+
grok.addPatternFromFile(context.getProperty(PATTERN_FILE).getValue());
--- End diff --
Good catch. Overlooked it.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
