internal/contour: Add contour version to metrics

[poidag-zz]

Fixes #2378

Signed-off-by: Peter Grant [email protected]

Allows for passing version at build time and exposes build information as a metric.

[poidag-zz]

@jpeach I have not taken a look at metrics documentation auto-generation yet.

[codecov]

Codecov Report

Merging #2383 into master will increase coverage by 0.28%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2383      +/-   ##
==========================================
+ Coverage   77.83%   78.12%   +0.28%     
==========================================
  Files          61       62       +1     
  Lines        5248     5288      +40     
==========================================
+ Hits         4085     4131      +46     
+ Misses       1075     1069       -6     
  Partials       88       88              

Impacted Files	Coverage Δ
internal/metrics/metrics.go	85.32% <100.00%> (+0.63%)	⬆️
internal/dag/cache.go	95.43% <0.00%> (-0.71%)	⬇️
internal/contour/endpointstranslator.go	83.03% <0.00%> (-0.59%)	⬇️
internal/contour/listener.go	92.10% <0.00%> (-0.35%)	⬇️
internal/envoy/route.go	98.45% <0.00%> (-0.04%)	⬇️
internal/contour/cluster.go	100.00% <0.00%> (ø)
internal/protobuf/helpers.go	100.00% <0.00%> (ø)
internal/sorter/sorter.go	97.27% <0.00%> (ø)
internal/envoy/listener.go	96.15% <0.00%> (+1.09%)	⬆️
internal/contour/route.go	92.92% <0.00%> (+1.26%)	⬆️
... and 1 more

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[jpeach]

I think that this is heading in the right direction.

Can you please change the commit message from internal\contour to internal/contour?

[poidag-zz]

Have made some changes and this is how it's currently looking

/ # curl -s contour.projectcontour:8000/metrics | grep build
# HELP contour_build_info Build information for Contour
# TYPE contour_build_info gauge
contour_build_info{branch="metrics-version",revision="3ef9cbc4a72363c0cac409d030db9a1146b8ac2e",version="v1.3.0-21-g3ef9cbc4"} 1

[jpeach]

This looks good to me. Just address the last editorial nits are we are ready to go.

[jpeach]

@stevesloka Are you OK with using a separate package for the version information here?

[stevesloka]

Are you OK with using a separate package for the version information here?

I think the build package could be used for many things. My reference before on the sort package was I could hear @davecheney in my head asking me what the package was responsible for if it couldn't do a single thing and to think about that name.

For this, I think it's fine.