Fix NameError of SecondaryFileOutput when setting secondary other than out_secondary_file

[daipom]

Which issue(s) this PR fixes:
None.

Fix bug of 3a796cd

• Suppress warning using different secondary for out_secondary_file #4087

What this PR does / why we need it:

In Fluentd v1.16.0, the following setting causes NameError and Fluentd to fail to start.

<match test.**>
  @type stdout
  <buffer>
    @type memory
  </buffer>
  <secondary>
    @type file
    path /tmp/backup/
  </secondary>
</match>

Error

$ bundle exec fluentd -c .\fluent\fluent.conf
2023-04-03 18:49:11 +0900 [info]: init supervisor logger path=nil rotate_age=nil rotate_size=nil
2023-04-03 18:49:11 +0900 [info]: parsing config file is succeeded path=".\\fluent\\fluent.conf"
2023-04-03 18:49:11 +0900 [info]: gem 'fluentd' version '1.16.0'
C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/plugin/output.rb:429:in `configure': uninitialized constant Fluent::Plugin::Output::SecondaryFileOutput (NameError)

          if (@secondary.class != SecondaryFileOutput) &&
                                  ^^^^^^^^^^^^^^^^^^^
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/plugin_helper/formatter.rb:83:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/plugin_helper/inject.rb:104:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/plugin/out_stdout.rb:52:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/plugin.rb:187:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/agent.rb:132:in `add_match'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/agent.rb:74:in `block in configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/agent.rb:64:in `each'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/agent.rb:64:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/root_agent.rb:149:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/engine.rb:105:in `configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/engine.rb:80:in `run_configure'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/supervisor.rb:571:in `run_supervisor'
        from C:/Users/reang/Documents/work/fluentd/fluentd/lib/fluent/command/fluentd.rb:352:in `<top (required)>'
        from <internal:C:/Ruby32-x64/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
        from <internal:C:/Ruby32-x64/lib/ruby/site_ruby/3.2.0/rubygems/core_ext/kernel_require.rb>:37:in `require'
        from C:/Users/reang/Documents/work/fluentd/fluentd/bin/fluentd:15:in `<top (required)>'
        from C:/Ruby32-x64/lib/ruby/gems/3.2.0/bin/fluentd:25:in `load'
        from C:/Ruby32-x64/lib/ruby/gems/3.2.0/bin/fluentd:25:in `<main>'

This PR fixes this bug.

In #4087, I could not notice this error since this error would not occur if out_secondary_file is set once before such a setting.
I'm sorry for my careless mistake.

Docs Changes:
Not needed.

Release Note:
Same as the title.

[ashie]

We noticed this issue in fluent/fluent-package-builder#436

[daipom]

I confirmed this behavior.

Config:

<match test.**>
  @type stdout
  @id file
  <buffer>
    @type memory
  </buffer>
  <secondary>
    @type file
    path /tmp/backup/
  </secondary>
</match>

<match test.**>
  @type stdout
  @id secondary_file
  <buffer>
    @type memory
  </buffer>
  <secondary>
    @type secondary_file
    directory /tmp/backup
  </secondary>
</match>

Run Fluentd:

$ bundle exec fluentd -c .\fluent\fluent.conf
2023-04-03 19:04:23 +0900 [info]: init supervisor logger path=nil rotate_age=nil rotate_size=nil
2023-04-03 19:04:23 +0900 [info]: parsing config file is succeeded path=".\\fluent\\fluent.conf"
2023-04-03 19:04:23 +0900 [info]: gem 'fluentd' version '1.16.0'
2023-04-03 19:04:23 +0900 [warn]: [file] Use different plugin for secondary. Check the plugin works with primary like secondary_file primary="Fluent::Plugin::StdoutOutput" secondary="Fluent::Plugin::FileOutput"
2023-04-03 19:04:23 +0900 [info]: using configuration file: <ROOT>
  <match test.**>
    @type stdout
    @id file
    <buffer>
      @type "memory"
    </buffer>
    <secondary>
      @type "file"
      path "/tmp/backup/"
      <buffer time>
        path /tmp/backup/
      </buffer>
    </secondary>
  </match>
  <match test.**>
    @type stdout
    @id secondary_file
    <buffer>
      @type "memory"
    </buffer>
    <secondary>
      @type "secondary_file"
      directory "/tmp/backup"
    </secondary>
  </match>
</ROOT>
2023-04-03 19:04:23 +0900 [info]: starting fluentd-1.16.0 pid=5300 ruby="3.2.0"
2023-04-03 19:04:23 +0900 [info]: spawn command to main:  cmdline=["C:/Ruby32-x64/bin/ruby.exe", "-rC:/Ruby32-x64/lib/ruby/gems/3.2.0/gems/bundler-2.4.8/lib/bundler/setup", "-Eutf-8", "C:/Ruby32-x64/lib/ruby/gems/3.2.0/bin/fluentd", "-c", ".\\fluent\\fluent.conf", "--under-supervisor"]
2023-04-03 19:04:26 +0900 [info]: #0 init worker0 logger path=nil rotate_age=nil rotate_size=nil
2023-04-03 19:04:26 +0900 [info]: adding match pattern="test.**" type="stdout"
2023-04-03 19:04:26 +0900 [warn]: #0 [file] Use different plugin for secondary. Check the plugin works with primary like secondary_file primary="Fluent::Plugin::StdoutOutput" secondary="Fluent::Plugin::FileOutput"
2023-04-03 19:04:26 +0900 [info]: adding match pattern="test.**" type="stdout"
2023-04-03 19:04:26 +0900 [info]: #0 starting fluentd worker pid=22656 ppid=5300 worker=0
2023-04-03 19:04:26 +0900 [info]: #0 fluentd worker is now running worker=0

• No NameError.
• The plugin with out_file for its secondary gets warning.
• The plugin with out_secondary_file for its secondary doesn't get warning.

[ashie]

LGTM

[daipom]

Thanks for your review!