Release v1.15.0-rc.1

[MrAlias]

This is a release candidate for the v1.15.0/v0.38.0 release. That release will include the v1 release of the OpenTelemetry Go metric API and will provide stability guarantees of that API. See our versioning policy for more information about these stability guarantees.

This release drops the compatibility guarantee of Go 1.18.

Added

• Support global MeterProvider in go.opentelemetry.io/otel. (Support a global MeterProvider in go.opentelemetry.io/otel #3818)
  • Use Meter for a metric.Meter from the global metric.MeterProvider.
  • Use GetMeterProivder for a global metric.MeterProvider.
  • Use SetMeterProivder to set the global metric.MeterProvider.

Changed

• Dropped compatibility testing for Go 1.18. The project no longer guarantees support for this version of Go. (Drop compatibility testing for Go 1.18 #3813)

Fixed

• Handle empty environment variable as it they were not set. (Handle empty env vars as it they were not set #3764)

Deprecated

• The go.opentelemetry.io/otel/metric/global package is deprecated. Use go.opentelemetry.io/otel instead. (Support a global MeterProvider in go.opentelemetry.io/otel #3818)

Removed

• The deprecated go.opentelemetry.io/otel/metric/unit package is removed. (Remove the deprecated metric/unit package #3814)

[MrAlias]

Blocked by open-telemetry/opentelemetry-go-contrib#3518

[codecov]

Codecov Report

Merging #3825 (d83c489) into main (8139361) will increase coverage by 0.0%.
The diff coverage is 100.0%.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3825   +/-   ##
=====================================
  Coverage   81.6%   81.6%           
=====================================
  Files        170     170           
  Lines      12474   12474           
=====================================
+ Hits       10188   10190    +2     
+ Misses      2071    2069    -2     
  Partials     215     215           

Impacted Files	Coverage Δ
version.go	100.0% <100.0%> (ø)
sdk/trace/batch_span_processor.go	81.1% <0.0%> (+0.8%)	⬆️