Document gzip usage

README.md

@@ -38,16 +38,21 @@ There are two [Rack][2] middlewares available, one to expose a metrics HTTP
 endpoint to be scraped by a prometheus server ([Exporter][9]) and one to trace all HTTP
 requests ([Collector][10]).
 
+It's highly recommended to enable gzip compression for the metrics endpoint,
+for example by including the `Rack::Deflater` middleware.
+
 ```ruby
 # config.ru
 
 require 'rack'
 require 'prometheus/client/rack/collector'
 require 'prometheus/client/rack/exporter'
 
+use Rack::Deflater, if: ->(env, status, headers, body) { body.any? && body[0].length > 512 }
 use Prometheus::Client::Rack::Collector
 use Prometheus::Client::Rack::Exporter
-run lambda { |env| [200, {'Content-Type' => 'text/html'}, ['OK']] }
+
+run ->(env) { [200, {'Content-Type' => 'text/html'}, ['OK']] }
 ```
 
 Start the server and have a look at the metrics endpoint:

examples/rack/README.md

@@ -5,20 +5,8 @@ and `Rack::Collector` rack middlwares.
 
 ## Usage
 
-Start the Server.
+Execute the provided `run` script:
 
 ```bash
-unicorn -p 5000 -c unicorn.conf
-```
-
-Benchmark number of requests.
-
-```bash
-ab -c 10 -n 1000 http://127.0.0.1:5000/
-```
-
-View the metrics output.
-
-```bash
-curl http://127.0.0.1:5000/metrics
+./run
 ```

examples/rack/config.ru

@@ -4,6 +4,8 @@ require 'rack'
 require 'prometheus/client/rack/collector'
 require 'prometheus/client/rack/exporter'
 
+use Rack::Deflater, if: ->(env, status, headers, body) { body.any? && body[0].length > 512 }
 use Prometheus::Client::Rack::Collector
 use Prometheus::Client::Rack::Exporter
+
 run ->(_) { [200, { 'Content-Type' => 'text/html' }, ['OK']] }

examples/rack/run

@@ -6,12 +6,15 @@ installed() {
 	which $1 > /dev/null
 }
 
-fatal() {
+log() {
 	echo >&2 $1
+}
+
+fatal() {
+	log $1
 	exit 1
 }
 
-# check dependencies
 if ! installed vegeta; then
 	if ! installed go; then
 		fatal "Could not find go. Either run the examples manually or install"
@@ -24,15 +27,15 @@ fi
 PORT=5000
 URL=http://127.0.0.1:${PORT}/
 
-# start example server
+log "starting example server"
 bundle install --quiet
 bundle exec unicorn -p ${PORT} -c unicorn.conf &>> /dev/null &
 
 # wait until unicorn is available
 sleep 1
 
-# do requests
-printf "GET ${URL}\nPOST ${URL}\nDELETE ${URL}" | vegeta attack &>> /dev/null
+log "sending requests for 5 seconds"
+printf "GET ${URL}\nPOST ${URL}\nDELETE ${URL}" | vegeta attack -duration 5s &>> /dev/null
 
-# output the result
+log "printing /metrics"
 curl -s "${URL}metrics"