[opentelemetry-otlp] adds an example HTTP exporter backed by Hyper

[markdingram]

Resolves #1659

Given the Pending Hyper 1.0 upgrade seems to make sense for Hyper 0.14 Client support to be provided as an example.

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.0%. Comparing base (028d3e7) to head (a4f018a).

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #1861   +/-   ##
=====================================
  Coverage   75.0%   75.0%           
=====================================
  Files        122     122           
  Lines      20279   20279           
=====================================
+ Hits       15211   15212    +1     
+ Misses      5068    5067    -1     

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[cijothomas]

From 6/4/ community call:
Please see if we can use the existing examples, and add feature flags to it to showcase diff. http clients, instead of maintaining full examples for each of them.

[cijothomas]

From 6/4/ community call: Please see if we can use the existing examples, and add feature flags to it to showcase diff. http clients, instead of maintaining full examples for each of them.

@markdingram Would you be willing to change this based on this recommendation? Thanks in advance!

[markdingram]

From 6/4/ community call: Please see if we can use the existing examples, and add feature flags to it to showcase diff. http clients, instead of maintaining full examples for each of them.

@markdingram Would you be willing to change this based on this recommendation? Thanks in advance!

I had a go

[cijothomas]

Suggested change

	By default the app will use a `reqwest` client to send. A hyper 0.14 client can be used with the `hyper` feature enabled
	By default the app will use a `reqwest` client to send. A hyper client can be used with the `hyper` feature enabled

[cijothomas]

Thanks!
Will wait for one more approval to merge. (My own experience with hyper is limited, so need an extra pair of eyes)

[lalitb]

Do you think we can instead update the HttpConfig in opentelemetry-otlp to support the hyper client, and so use the hyper related code from opentelemetry-http. I don't know if hyper 1.0 is the blocker for that?

[lalitb]

@markdingram please see if this makes sense - #1861 (comment)

[markdingram]

@markdingram please see if this makes sense - #1861 (comment)

Anything done now will conflict with #1674 - I will look again once the crate upgrades are through.

[lalitb]

@markdingram please see if this makes sense - #1861 (comment)

Anything done now will conflict with #1674 - I will look again once the crate upgrades are through.

should be good, assuming we will revisit this once #1674 is through.