Incorrect instructions to build a fluentd with elasticsearch-plugin for docker image

[stiliajohny]

Describe the bug

At the page https://docs.fluentd.org/v/0.12/articles/docker-logging-efk-compose
The instructions given on https://docs.fluentd.org/v/0.12/articles/docker-logging-efk-compose#step-1-prepare-fluentd-image-with-your-config-+-plugin are incorrect

This has been tested on MacOS ( docker desktop ) and Archlinux ( docker runtime )

The current error if these instructions are used is

Click to expand for error log

```bash etching excon-0.90.0.gem # terminated with exception (report_on_exception is true): /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `initialize': Permission denied @ rb_sysopen - /usr/local/bundle/cache/excon-0.90.0.gem (Errno::EACCES) from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `open' from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `write_binary' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:305:in `cache_update_path' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:158:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/source.rb:206:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/resolver/specification.rb:101:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/request_set.rb:174:in `block (2 levels) in install' Fetching faraday-net_http-1.0.1.gem # terminated with exception (report_on_exception is true): /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `initialize': Permission denied @ rb_sysopen - /usr/local/bundle/cache/faraday-net_http-1.0.1.gem (Errno::EACCES) from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `open' from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `write_binary' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:305:in `cache_update_path' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:158:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/source.rb:206:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/resolver/specification.rb:101:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/request_set.rb:174:in `block (2 levels) in install' Fetching ruby2_keywords-0.0.5.gem # terminated with exception (report_on_exception is true): /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `initialize': Permission denied @ rb_sysopen - /usr/local/bundle/cache/ruby2_keywords-0.0.5.gem (Errno::EACCES) from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `open' from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `write_binary' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:305:in `cache_update_path' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:158:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/source.rb:206:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/resolver/specification.rb:101:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/request_set.rb:174:in `block (2 levels) in install' Fetching faraday-retry-1.0.3.gem # terminated with exception (report_on_exception is true): /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `initialize': Permission denied @ rb_sysopen - /usr/local/bundle/cache/faraday-retry-1.0.3.gem (Errno::EACCES) from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `open' from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `write_binary' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:305:in `cache_update_path' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:158:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/source.rb:206:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/resolver/specification.rb:101:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/request_set.rb:174:in `block (2 levels) in install' Fetching faraday-net_http_persistent-1.2.0.gem # terminated with exception (report_on_exception is true): /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `initialize': Permission denied @ rb_sysopen - /usr/local/bundle/cache/faraday-net_http_persistent-1.2.0.gem (Errno::EACCES) from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `open' from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `write_binary' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:305:in `cache_update_path' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:158:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/source.rb:206:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/resolver/specification.rb:101:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/request_set.rb:174:in `block (2 levels) in install' Fetching faraday-rack-1.0.0.gem # terminated with exception (report_on_exception is true): /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `initialize': Permission denied @ rb_sysopen - /usr/local/bundle/cache/faraday-rack-1.0.0.gem (Errno::EACCES) from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `open' from /usr/local/lib/ruby/2.6.0/rubygems.rb:876:in `write_binary' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:305:in `cache_update_path' from /usr/local/lib/ruby/2.6.0/rubygems/remote_fetcher.rb:158:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/source.rb:206:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/resolver/specification.rb:101:in `download' from /usr/local/lib/ruby/2.6.0/rubygems/request_set.rb:174:in `block (2 levels) in install' ERROR: While executing gem ... (Errno::EACCES) Permission denied @ rb_sysopen - /usr/local/bundle/cache/faraday-rack-1.0.0.gem ```

Link to the problematic documentation

https://docs.fluentd.org/v/0.12/articles/docker-logging-efk-compose#step-1-prepare-fluentd-image-with-your-config-+-plugin

Expected explanation

Update the document,
The most appropriate documentations I have found was under https://hub.docker.com/r/fluent/fluentd/ on the section 3. Customize Dockerfile to install plugins (optional) in particular 3.1 For current images

I would suggest either copy the context of one of the dockerfiles or point the user reading the initial docs to the dockerhub docs ( the first option is more optimal IMO)

Additional context

this document was reviewed d2 years ago, it is expected technology, dependencies and implementation to have change.

[cosmo0920]

Have you tested on v1 version of documentation instruction? Fluentd v0.12 is already EOL and not maintained.

[stiliajohny]

Have you tested on v1 version of documentation instruction? Fluentd v0.12 is already EOL and not maintained.

Aw, that might be one of the reasons,
After googling I didn't ended up on this link :)

Might be worth having a banner or a suggestion to visit the latest docs

Thanks so much for that !!