Fluentd не может обработать файл лога

Пробую настроить с нуля Fluentd в кластере Kubernetes для стака FLG. Мне нужно захватывать файлы логов по шаблону имени, обрабатывать их содержимое и пересылать полученные записи в Loki. Однако при обработке файла логов я получаю ошибку:

2024-05-07 16:22:58 +0300 [warn]: #0 got unrecoverable error in primary and no secondary error_class=NoMethodError error="undefined method `each' for nil:NilClass"
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluent-plugin-loki-0.3.0/lib/fluent/plugin/out_loki.rb:184:in `format_labels'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluent-plugin-loki-0.3.0/lib/fluent/plugin/out_loki.rb:191:in `handle_record'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluent-plugin-loki-0.3.0/lib/fluent/plugin/out_loki.rb:223:in `block in write'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/event.rb:319:in `each'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/event.rb:319:in `block in each'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/plugin/buffer/memory_chunk.rb:81:in `open'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/plugin/buffer/memory_chunk.rb:81:in `open'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/event.rb:318:in `each'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluent-plugin-loki-0.3.0/lib/fluent/plugin/out_loki.rb:222:in `write'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/plugin/output.rb:1225:in `try_flush'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/plugin/output.rb:1538:in `flush_thread_run'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/plugin/output.rb:510:in `block (2 levels) in start'
  2024-05-07 16:22:58 +0300 [warn]: #0 /fluentd/vendor/bundle/ruby/3.2.0/gems/fluentd-1.16.5/lib/fluent/plugin_helper/thread.rb:78:in `block in thread_create'
2024-05-07 16:22:58 +0300 [warn]: #0 bad chunk is moved to /tmp/fluent/backup/worker0/object_80c/617dd150cde458ebebfae8b4f4b0af7f.log

Мой конфиг для Fluentd:

apiVersion: v1
kind: ConfigMap
metadata:
  name: fluentd-logging
  namespace: monitoring
  labels:
    app: fluentd-logging
data: 
  fluent.conf: |
    <system>
      log_level warn
    </system>

    <source>
      @type tail
      path /tmp/logs/srv-kube-master-01/commands.log*
      pos_file /var/log/fluentd/tmp/access.log.pos
      tag kubernetes.master01.system.commands
      read_from_head true
      <parse>
        @type regexp
        expression /(?<time>[a-zA-Z]+\s{1,2}\d{1,2}\s\d{2}:\d{2}:\d{2})\s(?<host>[\w-]+)\s(?<user>[\w]+):\s{2}\[(?<pid>\d+)\]\s(?<command>.*)/
        time_format %b %d %H:%M:%S
      </parse>
    </source>

    <match kubernetes.master01.system.commands>
      @type loki
      endpoint_url "http://loki:3100/loki/api/v1/push"
      # label_keys srv-kube-master-01
      # buffer_type memory
      # buffer_chunk_limit 1m
      <buffer>
        flush_interval 10s
        flush_at_shutdown true
      </buffer>
      # label {env: "dev"}
      # <line_format>
      #   key_name "command"
      # </line_format>
    </match>

Содержимое обрабатываемого файла логов:

Apr  8 15:28:44 srv-kube-master-01 root:  [1396657] exit
Apr  8 15:28:47 srv-kube-master-01 root:  [1396657] export
Apr  8 15:29:04 srv-kube-master-01 root:  [1396657] cat /etc/bash.bashrc
Apr  8 15:29:26 srv-kube-master-01 root:  [1396657] ll
Apr  8 15:29:33 srv-kube-master-01 root:  [1396657] cat commands.log
Apr  9 10:29:53 srv-kube-master-01 kubemaster:  [717392] exit
Apr  9 10:31:54 srv-kube-master-01 kubemaster:  [717392] sudo crontab -e

Я использую образ fluent/fluentd-kubernetes-daemonset:v1.16.5-debian-forward-1.0 и grafana/loki:latest.

Что мне нужно исправить для того, чтобы обработка логов работала корректно?