Add support for ${} substitution about fluent-plugin-s3

[kiyoto]

Lance-

Can you try doing

aws_api_key '#{ENV['AWS_API_KEY']}"

(Note the double quotes)

[kiyoto]

Also, I updated the docs's faq > fluent/fluentd-docs@6e5dd3d

[repeatedly]

You can use --use-v1-config. This is not fluent-plugin-s3 issue.

[LanceNorskog]

Yes, this works:
aws_api_key "#{ENV['AWS_API_KEY']}"

I have not needed double-quotes in other plugins. I'm using td-agent with --use-v1-config.
(Your example has 3 single quotes and one double. Keyboard-complete is so hard to get right :)

[repeatedly]

I have not needed double-quotes in other plugins

You mean ${}, not "#{}", right?
${} is parsed by plugin itself but "#{}" is parsed by fluentd configuration parser.
non-quoted string is for writing string without escape so "" is needed for evaluating Ruby code.

[LanceNorskog]

Thanks, that makes sense.