Propagate Remote Sampling Host port correctly

[joe-elliott]

Added propagation code/tests.

Fixes #492

cc @annanay25

[pjanotti]

Hi @joe-elliott - is it the idea that this parameter is going to always be required?

[joe-elliott]

@pjanotti

Yup. When Annanay added the remote sampling proxy functionality he forgot to add a way to configure the listening port. This PR amends that. Without this field remote sampling does not work.

[annanay25]

Aha, I assumed that remote sampling would be served over the http proxy be default.

[joe-elliott]

@pjanotti
I added a default host port. If none is specified it just uses Jaeger's default (5778). This way the operator only has to specify the fetch_endpoint and the it will automatically be hosted at default. This is now a valid config:

receivers:
  jaeger:
    protocols:
      grpc:
    remote_sampling:
      fetch_endpoint: "jaeger-collector:1234"

[codecov-io]

Codecov Report

Merging #507 into master will decrease coverage by <.01%.
The diff coverage is 71.42%.

@@            Coverage Diff             @@
##           master     #507      +/-   ##
==========================================
- Coverage   76.04%   76.04%   -0.01%     
==========================================
  Files         123      123              
  Lines        7627     7634       +7     
==========================================
+ Hits         5800     5805       +5     
- Misses       1552     1553       +1     
- Partials      275      276       +1

Impacted Files	Coverage Δ
receiver/jaegerreceiver/config.go	69.23% <ø> (ø)	⬆️
receiver/jaegerreceiver/factory.go	94.16% <71.42%> (-1.41%)	⬇️

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[pjanotti]

Thanks @joe-elliott! LGTM

[joe-elliott]

Thanks!