Remove JSON exposition format support

examples/rack/run

@@ -6,10 +6,6 @@ installed() {
 	which $1 > /dev/null
 }
 
-pretty_json() {
-	ruby -e "require 'json'; puts JSON.pretty_generate(JSON.load(STDIN))"
-}
-
 fatal() {
 	echo >&2 $1
 	exit 1
@@ -39,4 +35,4 @@ sleep 1
 printf "GET ${URL}\nPOST ${URL}\nDELETE ${URL}" | vegeta attack &>> /dev/null
 
 # output the result
-curl -s "${URL}metrics" | pretty_json
+curl -s "${URL}metrics"

lib/prometheus/client/rack/exporter.rb

@@ -1,7 +1,6 @@
 # encoding: UTF-8
 
 require 'prometheus/client'
-require 'prometheus/client/formats/json'
 require 'prometheus/client/formats/text'
 
 module Prometheus
@@ -12,8 +11,8 @@ module Rack
       class Exporter
         attr_reader :app, :registry, :path
 
-        FORMATS  = [Formats::Text, Formats::JSON]
-        FALLBACK = Formats::JSON
+        FORMATS  = [Formats::Text]
+        FALLBACK = Formats::Text
 
         def initialize(app, options = {})
           @app = app

spec/prometheus/client/rack/exporter_spec.rb

@@ -1,6 +1,5 @@
 # encoding: UTF-8
 
-require 'json'
 require 'rack/test'
 require 'prometheus/client/rack/exporter'
 
@@ -27,7 +26,6 @@
 
   context 'when requesting /metrics' do
     text = Prometheus::Client::Formats::Text
-    json = Prometheus::Client::Formats::JSON
 
     shared_examples 'ok' do |headers, fmt|
       it "responds with 200 OK and Content-Type #{fmt::CONTENT_TYPE}" do
@@ -43,7 +41,7 @@
 
     shared_examples 'not acceptable' do |headers|
       it 'responds with 406 Not Acceptable' do
-        message = 'Supported media types: text/plain, application/json'
+        message = 'Supported media types: text/plain'
 
         get '/metrics', nil, headers
 
@@ -54,37 +52,19 @@
     end
 
     context 'when client does not send a Accept header' do
-      include_examples 'ok', {}, json
+      include_examples 'ok', {}, text
     end
 
     context 'when client accpets any media type' do
-      accept = '*/*'
-
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, json
+      include_examples 'ok', { 'HTTP_ACCEPT' => '*/*' }, text
     end
 
     context 'when client requests application/json' do
-      accept = 'application/json'
-
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, json
-    end
-
-    context "when client requests '#{json::CONTENT_TYPE}'" do
-      accept = json::CONTENT_TYPE
-
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, json
+      include_examples 'not acceptable', 'HTTP_ACCEPT' => 'application/json'
     end
 
     context 'when client requests text/plain' do
-      accept = 'text/plain'
-
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
-    end
-
-    context "when client requests '#{text::CONTENT_TYPE}'" do
-      accept = text::CONTENT_TYPE
-
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
+      include_examples 'ok', { 'HTTP_ACCEPT' => 'text/plain' }, text
     end
 
     context 'when client uses different white spaces in Accept header' do
@@ -93,20 +73,14 @@
       include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
     end
 
-    context 'when client accepts multiple formats' do
-      accept = "#{json::CONTENT_TYPE};q=0.5, #{text::CONTENT_TYPE};q=0.7"
-
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
-    end
-
     context 'when client does not include quality attribute' do
-      accept = "#{json::CONTENT_TYPE};q=0.5, #{text::CONTENT_TYPE}"
+      accept = 'application/json;q=0.5, text/plain'
 
       include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
     end
 
     context 'when client accepts some unknown formats' do
-      accept = "#{text::CONTENT_TYPE};q=0.3, proto/buf;q=0.7"
+      accept = 'text/plain;q=0.3, proto/buf;q=0.7'
 
       include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
     end
@@ -120,7 +94,7 @@
     context 'when client accepts unknown formats and wildcard' do
       accept = 'fancy/woo;q=0.3, proto/buf;q=0.7, */*;q=0.1'
 
-      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, json
+      include_examples 'ok', { 'HTTP_ACCEPT' => accept }, text
     end
   end
 end