contrib: aws api coverage report script

quick 'n' dirty - might have some bugs, but it'll get us started

contrib/api-coverage/aws_api_coverage.rb

@@ -0,0 +1,49 @@
+#
+# This script generates CSV output reporting on the API Coverage of Terraform's
+# AWS Provider.
+#
+# In addition to Ruby, it depends on a properly configured Go development
+# environment with both terraform and aws-sdk-go present.
+#
+
+require 'csv'
+require 'json'
+require 'pathname'
+
+module APIs
+  module Terraform
+    def self.path
+      @path ||= Pathname(`go list -f '{{.Dir}}' github.com/hashicorp/terraform`.chomp)
+    end
+
+    def self.called?(api, op)
+      `git -C "#{path}" grep "#{api}.*#{op}" -- builtin/providers/aws | wc -l`.chomp.to_i > 0
+    end
+  end
+
+  module AWS
+    def self.path
+      @path ||= Pathname(`go list -f '{{.Dir}}' github.com/awslabs/aws-sdk-go/aws`.chomp).parent
+    end
+
+    def self.api_json_files
+      Pathname.glob(path.join('**', '*.normal.json'))
+    end
+
+    def self.each
+      api_json_files.each do |api_json_file|
+        json = JSON.parse(api_json_file.read)
+        api = api_json_file.dirname.basename
+        json["operations"].keys.each do |op|
+          yield api, op
+        end
+      end
+    end
+  end
+end
+
+csv = CSV.new($stdout)
+csv << ["API", "Operation", "Called in Terraform?"]
+APIs::AWS.each do |api, op|
+  csv << [api, op, APIs::Terraform.called?(api, op)]
+end