Dynamic Index Names via Filebeat

[dfir (Anthony)]

I am tying to use filebeat to ingest IIS logs. I can get this to work with basic configs in the iis.yml.

HOWEVER: there is a new need to be able to have filebeat create dynamic index names for IIS logs based on a folder name.

my IIS logs are stored: d:\01-evidence\iis\

Under this folder there WILL be folders with the following syntax: abc1234. the 1234 will be changing based on the case. the abc is always the same.

Here is the contents of the filebeat.yml.

So far: with the config below everything ingests but all of the data is part of the message column.

This Line is attempting to dynamically create the index. that worked, however the only fields visible in kibana were: metadata.folder and metadata.subfolder but the index name was correct.

index: "%{[fields.case_folder]}"  # Use folder name (e.g., ABZ1234) as the index name 

When the index Line was specified below I had all of the correct iis fields, however the index name was metadata_folder.

Can someone please assist with the correct configs to dynamically create index names based on a folder name?

index: "%{[case_folder]}"  # Use folder name (e.g., ABZ1234) as the index name 

###################### Filebeat Configuration Example #########################

# This file is an example configuration file highlighting only the most common
# options. The filebeat.reference.yml file from the same directory contains all the
# supported options with more comments. You can use it as a reference.
#
# You can find the full configuration reference here:
# https://www.elastic.co/guide/en/beats/filebeat/index.html

# For more available modules and options, please see the filebeat.reference.yml sample
# configuration file.

# ============================== Filebeat inputs ===============================

filebeat.inputs:

# Each - is an input. Most options can be set at the input level, so
# you can use different inputs for various configurations.
# Below are the input-specific configurations.

# filestream is an input for collecting log messages from files.
- type: log

  # Unique ID among all inputs, an ID is required.
  id: my-filestream-id

  # Change to true to enable this input configuration.
  enabled: true

  # Paths that should be crawled and fetched. Glob based paths.
  paths:
    #- /var/log/*.log
    - d:/01-evidence/iis/*/Logfiles/*/*.log

  # Exclude lines. A list of regular expressions to match. It drops the lines that are
  # matching any regular expression from the list.
  # Line filtering happens after the parsers pipeline. If you would like to filter lines
  # before parsers, use include_message parser.
  #exclude_lines: ['^DBG']

  # Include lines. A list of regular expressions to match. It exports the lines that are
  # matching any regular expression from the list.
  # Line filtering happens after the parsers pipeline. If you would like to filter lines
  # before parsers, use include_message parser.
  #include_lines: ['^ERR', '^WARN']

  # Exclude files. A list of regular expressions to match. Filebeat drops the files that
  # are matching any regular expression from the list. By default, no files are dropped.
  #prospector.scanner.exclude_files: ['.gz$']

  # Optional additional fields. These fields can be freely picked
  # to add additional information to the crawled log files for filtering
  fields:
    case_folder: "%{[metadata.folder]}" #Custom Field to hold Folder Name
  #  level: debug
  #  review: 1

# ============================== Filebeat modules ==============================

filebeat.config.modules:
  # Glob pattern for configuration loading
  path: ${path.config}/modules.d/*.yml

  # Set to true to enable config reloading
  reload.enabled: false

  # Period on which files under path should be checked for changes
  #reload.period: 10s

# ======================= Elasticsearch template setting =======================

setup.template.settings:
  index.number_of_shards: 1
  #index.codec: best_compression
  #_source.enabled: false


# ================================== General ===================================

# The name of the shipper that publishes the network data. It can be used to group
# all the transactions sent by a single shipper in the web interface.
#name:

# The tags of the shipper are included in their field with each
# transaction published.
#tags: ["service-X", "web-tier"]

# Optional fields that you can specify to add additional information to the
# output.
#fields:
#  env: staging

# ================================= Dashboards =================================
# These settings control loading the sample dashboards to the Kibana index. Loading
# the dashboards is disabled by default and can be enabled either by setting the
# options here or by using the `setup` command.
setup.dashboards.enabled: true
setup.template.name: "case-logs"
setup.template.pattern: "case-*"

# The URL from where to download the dashboard archive. By default, this URL
# has a value that is computed based on the Beat name and version. For released
# versions, this URL points to the dashboard archive on the artifacts.elastic.co
# website.
#setup.dashboards.url:

# =================================== Kibana ===================================

# Starting with Beats version 6.0.0, the dashboards are loaded via the Kibana API.
# This requires a Kibana endpoint configuration.
setup.kibana:

  # Kibana Host
  # Scheme and port can be left out and will be set to the default (http and 5601)
  # In case you specify and additional path, the scheme is required: http://localhost:5601/path
  # IPv6 addresses should always be defined as: https://[2001:db8::1]:5601
  host: "localhost:5601"

  # Kibana Space ID
  # ID of the Kibana Space into which the dashboards should be loaded. By default,
  # the Default Space will be used.
  #space.id:

# =============================== Elastic Cloud ================================

# These settings simplify using Filebeat with the Elastic Cloud (https://cloud.elastic.co/).

# The cloud.id setting overwrites the `output.elasticsearch.hosts` and
# `setup.kibana.host` options.
# You can find the `cloud.id` in the Elastic Cloud web UI.
#cloud.id:

# The cloud.auth setting overwrites the `output.elasticsearch.username` and
# `output.elasticsearch.password` settings. The format is `<user>:<pass>`.
#cloud.auth:

# ================================== Outputs ===================================

# Configure what output to use when sending the data collected by the beat.

# ---------------------------- Elasticsearch Output ----------------------------
output.elasticsearch:
  # Array of hosts to connect to.
  hosts: ["https://10.194.107.103:9200"]
  index: "%{[fields.case_folder]}"  # Use folder name (e.g., ABZ1234) as the index name
  bulk_max_size: 2048 #Increase bulk size to 2048 (default is 512)
  bulk_max_duration: 10s #Increase timeout to 10s (default is 5s)
  # Performance preset - one of "balanced", "throughput", "scale",
  # "latency", or "custom".
  preset: balanced

  # Protocol - either `http` (default) or `https`.
  #protocol: "https"

  # Authentication credentials - either API key or username/password.
  #api_key: "id:api_key"
  username: "un"
  password: "pass"
  ssl:
    enabled: true 
    ca_trusted_fingerprint: "4cfb7a8a3fc51932493e9d1fa5595e35c81bab9fbe20dc9b484429dad7e76a1c"

# ------------------------------ Logstash Output -------------------------------
#output.logstash:
  # The Logstash hosts
  #hosts: ["localhost:5044"]

  # Optional SSL. By default is off.
  # List of root certificates for HTTPS server verifications
  #ssl.certificate_authorities: ["/etc/pki/root/ca.pem"]

  # Certificate for SSL client authentication
  #ssl.certificate: "/etc/pki/client/cert.pem"

  # Client Certificate Key
  #ssl.key: "/etc/pki/client/cert.key"

# ================================= Processors =================================
processors: 
  - script:
        lang: javascript
        id: normalize_path
        source: >
          function process(event) {
              var path = event.Get("log.file.path");
              if (path) {
                  event.Put("log.file.path", path.replace(/\\\\/g, "/").replace(/\\/g, "/"));
              }
          }
  - dissect:
      tokenizer: "d:/01-evidence/iis/%{folder}/Logfiles/%{subfolder}/%{filename}"  # Extract the folder name dynamically
      field: "log.file.path"
      target_prefix: "metadata"
  - add_fields:
      target: ""
      fields:
        case_folder: "%{[metadata.folder]}"  # Add the folder name as a custom field
        subfolder:  "%{[metadata.subfolder]}" #Add the subfoler as a custom field
  #- add_host_metadata:
  #   when.not.contains.tags: forwarded
  #- add_cloud_metadata: ~
  #- add_docker_metadata: ~
  #- add_kubernetes_metadata: ~

# ================================== Logging ===================================

# Sets log level. The default log level is info.
# Available log levels are: error, warning, info, debug
logging:
  level: debug
  to_files: true
  files:
    path: "D:/logs/filebeat"
    name: filebeat
    keepfiles: 7
    permissions: 0644


# At debug level, you can selectively enable logging only for some components.
# To enable all selectors, use ["*"]. Examples of other selectors are "beat",
# "publisher", "service".
#logging.selectors: ["*"]

# ============================= X-Pack Monitoring ==============================
# Filebeat can export internal metrics to a central Elasticsearch monitoring
# cluster.  This requires xpack monitoring to be enabled in Elasticsearch.  The
# reporting is disabled by default.

# Set to true to enable the monitoring reporter.
#monitoring.enabled: false

# Sets the UUID of the Elasticsearch cluster under which monitoring data for this
# Filebeat instance will appear in the Stack Monitoring UI. If output.elasticsearch
# is enabled, the UUID is derived from the Elasticsearch cluster referenced by output.elasticsearch.
#monitoring.cluster_uuid:

# Uncomment to send the metrics to Elasticsearch. Most settings from the
# Elasticsearch outputs are accepted here as well.
# Note that the settings should point to your Elasticsearch *monitoring* cluster.
# Any setting that is not set is automatically inherited from the Elasticsearch
# output configuration, so if you have the Elasticsearch output configured such
# that it is pointing to your Elasticsearch monitoring cluster, you can simply
# uncomment the following line.
#monitoring.elasticsearch:

# ============================== Instrumentation ===============================

# Instrumentation support for the filebeat.
#instrumentation:
    # Set to true to enable instrumentation of filebeat.
    #enabled: false

    # Environment in which filebeat is running on (eg: staging, production, etc.)
    #environment: ""

    # APM Server hosts to report instrumentation results to.
    #hosts:
    #  - http://localhost:8200

    # API Key for the APM Server(s).
    # If api_key is set then secret_token will be ignored.
    #api_key:

    # Secret token for the APM Server(s).
    #secret_token:


# ================================= Migration ==================================

# This allows to enable 6.7 migration aliases
#migration.6_to_7.enabled: true

[dfir (Anthony)]

Closing this out.

I used this as a base guide for some adjustments to the Config:

Creating dynamic index name with Filebeat based on custom event field fails

I got this working after getting a better understanding of the concept of fields in filebeat and elasticsearch. In my case, the custom field I was referring to is created in the elasticsearch ingest pipeline. Those fields are not yet created/available to filebeat. What I did was use a primitive dissect processor within filebeat.yml to process the log message and extract the field I was interested in. That field is now available to be referenced in the filebeat.yml file. I then used that fie…