Handle HTTP API error responses

lib/prometheus/api_client/client.rb

@@ -104,7 +104,10 @@ def get(command, options)
       def run_command(command, options)
         response = get(command, options)
 
-        JSON.parse(response.body)['data']
+        body = JSON.parse(response.body)
+        raise RequestError, body['error'] if body['status'] != 'success'
+
+        body['data']
       rescue StandardError => err
         raise RequestError, err.message
       end

spec/prometheus/api_client/client_spec.rb

@@ -44,4 +44,35 @@
       end
     end
   end
+
+  describe '.run_command' do
+    it 'returns a hash' do
+      VCR.use_cassette('prometheus/api_client/client') do # , record: :new_episodes) do
+        prometheus = Prometheus::ApiClient::Client.new(
+          url:         url,
+          credentials: { token: token },
+          options:     { verify_ssl: OpenSSL::SSL::VERIFY_NONE },
+        )
+
+        response = prometheus.run_command(
+          "query_range",
+          { query: "up", start: "2015-07-01T20:10:30.781Z", end: "2015-07-01T20:11:00.781Z", step: "15s"}
+        )
+
+        expect(response).to eq({ "resultType"=>"matrix", "result"=>[], "explanation" => nil })
+      end
+    end
+
+    it 'raises on error' do
+      VCR.use_cassette('prometheus/api_client/client') do # , record: :new_episodes) do
+        prometheus = Prometheus::ApiClient::Client.new(
+          url:         url,
+          credentials: { token: token },
+          options:     { verify_ssl: OpenSSL::SSL::VERIFY_NONE },
+        )
+
+        expect { prometheus.run_command("query_ranage", { query: "(not a valid command"}) } .to raise_error(Prometheus::ApiClient::Client::RequestError)
+      end
+    end
+  end
 end