configurable sub-second precision with no time key

[sampointer]

For input plugins that do not provide a time key as part of the
record but do provide a time to the router, allow the degree
of sub-second time precision to be configurable.

Some sources (such as AWS CloudWatch) may provide an accurate time
source but do not include a time portion for an otherwise free-form
record: there is nothing to parse.

In this case the casting of a DateTime to a String loses any
sub-second precision.

(check all that apply)

• tests added
• tests passing
• README updated (if needed)
• README Table of Contents updated (if needed)
• History.md and version in gemspec are untouched
• backward compatible
• feature works in elasticsearch_dynamic (not required but recommended)

[coveralls]

Coverage increased (+0.01%) to 94.503% when pulling 64c7d7b on sampointer:add_configurable_time_precision_when_timestamp_missing into 83f978f on uken:master.

[coveralls]

Coverage increased (+0.01%) to 94.503% when pulling e3650a7 on sampointer:add_configurable_time_precision_when_timestamp_missing into 83f978f on uken:master.

[sampointer]

Hi! Is there anything I can do to help expedite this PR?

[Tom-Fawcett]

@sampointer how do you think this compares to #223?

[sampointer]

They're solving two different problems.

#223 is basically doing "fluentd API change stuff" for plugins, which basically amounts to moving some stuff around in the class hierarchy. fluentd have stuffed semver for their plugin API: fluent/fluentd#1449

This fixes a specific bug (and it is a bug) with a type cast losing time granularity in a specific situation.

They should both be merged.

[Tom-Fawcett]

@sampointer thanks for your explanation, I was just curious due to a specific similarity between your pull and #223 -

#223

+          record[TIMESTAMP_FIELD] = dt.iso8601(9).to_s

#249

+          record[TIMESTAMP_FIELD] = dt.iso8601(@time_precision)

Anyway, regarding getting this merged; @gihad 's comment on #250 explains that there is unfortunately no active maintainer at this time.

[gihad]

@sampointer I took a look at this PR - seems backwards compatible and everything looks good to me. Thanks for the contribution.

Regarding #223, does it looks good to you? I haven't looked in depth yet and I noticed there might be an outstanding question.

I will merge this one.

[Tom-Fawcett]

@gihad thanks for merging this one.

I notice that https://rubygems.org/gems/fluent-plugin-elasticsearch is still only showing 1.9.3 and not the two newer versions. Is that something you can resolve?

EDIT - @pitr helped out and published the newer versions.