Github user jagdeepsingh2 commented on a diff in the pull request:
https://github.com/apache/metron/pull/1245#discussion_r237716600
--- Diff: metron-platform/metron-parsers/README.md ---
@@ -52,6 +52,62 @@ There are two general types types of parsers:
This is using the default value for `wrapEntityName` if that
property is not set.
* `wrapEntityName` : Sets the name to use when wrapping JSON using
`wrapInEntityArray`. The `jsonpQuery` should reference this name.
* A field called `timestamp` is expected to exist and, if it does not,
then current time is inserted.
+ * Regular Expressions Parser
+ * `recordTypeRegex` : A regular expression to uniquely identify a
record type.
+ * `messageHeaderRegex` : A regular expression used to extract fields
from a message part which is common across all the messages.
+ * `convertCamelCaseToUnderScore` : If this property is set to true,
this parser will automatically convert all the camel case property names to
underscore seperated.
+ For example, following convertions will automatically happen:
+
+ ```
+ ipSrcAddr -> ip_src_addr
+ ipDstAddr -> ip_dst_addr
+ ipSrcPort -> ip_src_port
+ ```
+ Note this property may be necessary, because java does not
support underscores in the named group names. So in case your property naming
conventions requires underscores in property names, use this property.
+
+ * `fields` : A json list of maps contaning a record type to regular
expression mapping.
+
+ A complete configuration example would look like:
+
+ ```json
+ "convertCamelCaseToUnderScore": true,
+ "recordTypeRegex": "kernel|syslog",
+ "messageHeaderRegex":
"(<syslogPriority>(<=^<)\\d{1,4}(?=>)).*?(<timestamp>(<=>)[A-Za-z]
{3}\\s{1,2}\\d{1,2}\\s\\d{1,2}:\\d{1,2}:\\d{1,2}(?=\\s)).*?(<syslogHost>(<=\\s).*?(?=\\s))",
+ "fields": [
+ {
+ "recordType": "kernel",
+ "regex": ".*(<eventInfo>(<=\\]|\\w\\:).*?(?=$))"
+ },
+ {
+ "recordType": "syslog",
+ "regex":
".*(<processid>(<=PID\\s=\\s).*?(?=\\sLine)).*(<filePath>(<=64\\s)\/([A-Za-z0-9_-]+\/)+(?=\\w))
(<fileName>.*?(?=\")).*(<eventInfo>(<=\").*?(?=$))"
--- End diff --
I would say not any syslog message is expected to contain these feilds. But
it is expected that from **this form** of syslog message, we would extract
these fields (processid, fileName, filePath and eventInfo).
This configuration has been extracted from our use case. Our security
experts found this form of syslog message to be important from security
perspective. Now there could be other forms of syslog messages which we dont
care about.
---
