Example configuration for fluentd-es namespace per index using record_modifier and elasticsearch

es-config.txt

<filter kubernetes.**>
  @type kubernetes_metadata
</filter>

# Use tag as index name prefix by default
<filter **>
  @type record_modifier
  <record>
    _es_index ${tag_parts[0]}.${Time.at(time).strftime('%F')}
  </record>
</filter>

# If kubernetes namespace available, use that as index name prefix
<filter kubernetes.**>
  @type record_modifier
  <record>
    _es_index ${record['kubernetes']['namespace_name'] or 'kubernetes'}.${Time.at(time).strftime('%F')}
  </record>
</filter>

<match **>
  @id elasticsearch
  @type elasticsearch
  @log_level info
  include_tag_key true
  host elasticsearch
  port 9200
  logstash_format true
  target_index_key _es_index
  <buffer>
    @type file
    path /var/log/fluentd-buffers/kubernetes.system.buffer
    flush_mode interval
    retry_type exponential_backoff
    flush_thread_count 2
    flush_interval 5s
    retry_forever
    retry_max_interval 30
    chunk_limit_size 2M
    queue_limit_length 8
    overflow_action block
  </buffer>
</match>