docs: relocate Resque config option comments to render in Yard docs (#…

…834)

docs: move config option docs up to the Instrumentation class

As formatted markdown comments on the class, the information is made visible
in the Yard-generated docs without making the options appear to be class or
instance variables.

instrumentation/resque/lib/opentelemetry/instrumentation/resque.rb

@@ -9,7 +9,7 @@
 
 module OpenTelemetry
   module Instrumentation
-    # Contains the OpenTelemetry instrumentation for the Resque gem
+    # (see OpenTelemetry::Instrumentation::Resque::Instrumentation)
     module Resque
     end
   end

instrumentation/resque/lib/opentelemetry/instrumentation/resque/instrumentation.rb

@@ -7,7 +7,61 @@
 module OpenTelemetry
   module Instrumentation
     module Resque
-      # The Instrumentation class contains logic to detect and install the Resque instrumentation
+      # The {OpenTelemetry::Instrumentation::Resque::Instrumentation} class contains logic to detect and install the Resque instrumentation
+      #
+      # Installation and configuration of this instrumentation is done within the
+      # {https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry/SDK#configure-instance_method OpenTelemetry::SDK#configure}
+      # block, calling {https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry%2FSDK%2FConfigurator:use use()}
+      # or {https://www.rubydoc.info/gems/opentelemetry-sdk/OpenTelemetry%2FSDK%2FConfigurator:use_all use_all()}.
+      #
+      # ## Configuration keys and options
+      #
+      # ### `:span_naming`
+      #
+      # Specifies how the span names are set. Can be one of:
+      #
+      # - `:queue` **(default)** - The job span name will appear as '<destination / queue name> <operation>',
+      #   for example `default process`.
+      # - `:job_class` - The job span name will appear as '<job class name> <operation>',
+      #   for example `SimpleJob process`.
+      #
+      # ### `:propagation_style`
+      #
+      # Specifies how the job's execution is traced and related to the trace where the job was enqueued.
+      #
+      # - `:link` **(default)** - The job will be represented by a separate trace from the span that enqueued the job.
+      #     - The initial span of the job trace will be associated with the span that enqueued the job, via a
+      #       {https://opentelemetry.io/docs/concepts/signals/traces/#span-links Span Link}.
+      # - `:child` - The job will be represented within the same logical trace, as a direct
+      #   child of the span that enqueued the job.
+      # - `:none` - The job will be represented by a separate trace from the span that enqueued the job.
+      #   There will be no explicit relationship between the job trace and the trace containing the span that
+      #   enqueued the job.
+      #
+      # ### `:force_flush`
+      #
+      # Specifies whether spans are forcibly flushed (exported out of process) upon every job completion.
+      #
+      #   - `:ask_the_job` **(default)** - Synchronously flush completed spans when a job completes if workers are
+      #     forked for each job.
+      #       - Determined by checking if {https://www.rubydoc.info/gems/resque/Resque%2FWorker:fork_per_job%3F Resque::Worker#fork_per_job?}
+      #         is true. Spans must be flushed and exported before a worker process terminates or no telemetry will be sent.
+      #   - `:always` - All completed spans will be synchronously flushed at the end of a job's execution.
+      #   - `:never` - Job completion will not affect the export of spans out of worker processes.
+      #       - Selecting this option will result in spans being lost if the worker process ends before
+      #         the spans are flushed. You might select this option if you wish to coordinate the timing for flushing
+      #         completed spans yourself.
+      #
+      # @example An explicit default configuration
+      #   OpenTelemetry::SDK.configure do |c|
+      #     c.use_all({
+      #       'OpenTelemetry::Instrumentation::Resque' => {
+      #         span_naming: :queue,
+      #         propagation_style: :link
+      #         force_flush: :ask_the_job,
+      #       },
+      #     })
+      #   end
       class Instrumentation < OpenTelemetry::Instrumentation::Base
         install do |_config|
           require_dependencies
@@ -18,30 +72,6 @@ class Instrumentation < OpenTelemetry::Instrumentation::Base
           defined?(::Resque)
         end
 
-        ## Supported configuration keys for the install config hash:
-        #
-        # force_flush: controls if spans are forcibly flushed upon job completion
-        #   - :ask_the_job (default) - if `Resque::Worker#fork_per_job?` is set,
-        #     all completed spans will be synchronously flushed at the end of a
-        #     job's execution
-        #   - :always - all completed spans will be synchronously flushed at the
-        #     end of a job's execution
-        #   - :never - the job will not intervene with the processing of spans
-        #
-        # span_naming: when `:job_class`, the span names will be set to
-        #   '<job class name> <operation>'. When `:queue`, the span names
-        #   will be set to '<destination / queue name> <operation>'
-        #
-        # propagation_style: controls how the job's execution is traced and related
-        #   to the trace where the job was enqueued. Can be one of:
-        #   - :link (default) - the job will be executed in a separate trace. The
-        #     initial span of the execution trace will be linked to the span that
-        #     enqueued the job, via a Span Link.
-        #   - :child - the job will be executed in the same logical trace, as a direct
-        #     child of the span that enqueued the job.
-        #   - :none - the job's execution will not be explicitly linked to the span that
-        #     enqueued the job.
-
         option :force_flush,       default: :ask_the_job, validate: %I[ask_the_job always never]
         option :span_naming,       default: :queue,       validate: %I[job_class queue]
         option :propagation_style, default: :link,        validate: %i[link child none]