Using Morphlines with Syslog

This example illustrates using a morphline to extract information from a syslog file.

A syslog file contains semi-structured lines of the following form:

<164>Feb  4 10:46:14 syslog sshd[607]: listening on port 22.

The program extracts the following record from the log line and loads it into Solr:

syslog_timestamp:Feb  4 10:46:14
syslog_message:listening on port 22.

Use the following rules to create a chain of transformation commands, which are expressed with the readLine, grok, and logDebug morphline commands, by editing a morphline.conf file.

# Specify server locations in a SOLR_LOCATOR variable; used later in
# variable substitutions:
  # Name of solr collection
  collection : collection1

  # ZooKeeper ensemble
  zkHost : ""

# Specify an array of one or more morphlines, each of which defines an ETL
# transformation chain. A morphline consists of one or more potentially
# nested commands. A morphline is a way to consume records such as Flume events,
# HDFS files or blocks, turn them into a stream of records, and pipe the stream
# of records through a set of easily configurable transformations on the way to
# a target application such as Solr.
morphlines : [
    id : morphline1
    importCommands : ["org.kitesdk.**"]

    commands : [
        readLine {
          charset : UTF-8

        grok {
          # a grok-dictionary is a config file that contains prefabricated regular expressions
          # that can be referred to by name.
          # grok patterns specify such a regex name, plus an optional output field name.
          # The syntax is %{REGEX_NAME:OUTPUT_FIELD_NAME}
          # The input line is expected in the "message" input field.
          dictionaryFiles : [target/test-classes/grok-dictionaries]
          expressions : {
            message : """<%{POSINT:syslog_pri}>%{SYSLOGTIMESTAMP:syslog_timestamp} %{SYSLOGHOST:syslog_hostname} %{DATA:syslog_program}(?:\[%{POSINT:syslog_pid}\])?: %{GREEDYDATA:syslog_message}"""

      # Consume the output record of the previous command and pipe another
      # record downstream.
      # This command deletes record fields that are unknown to Solr
      # schema.xml.
      # Recall that Solr throws an exception on any attempt to load a document
      # that contains a field that is not specified in schema.xml.
        sanitizeUnknownSolrFields {
          # Location from which to fetch Solr schema
          solrLocator : ${SOLR_LOCATOR}

      # log the record at DEBUG level to SLF4J
      { logDebug { format : "output record: {}", args : ["@{}"] } }

      # load the record into a Solr server or MapReduce Reducer
        loadSolr {
          solrLocator : ${SOLR_LOCATOR}