fix: api batch yaml separator

[smehboub]

Hello,

When i execute the slo-generator as api mode with a batch request with some files sample, by example this one : https://github.com/google/slo-generator/blob/master/samples/cloud_monitoring/slo_gae_app_latency.yaml

$ slo-generator api -c config.yaml

$ curl -X POST -H "Content-Type: text/x-yaml" --data-binary @slo_gae_app_latency.yaml "http://localhost:8080?batch=true"

Because the yaml file separator is ";" in the batch process request method, you can see that here : https://github.com/google/slo-generator/blob/master/slo_generator/api/main.py#L205
And than the slo_gae_app_latency.yaml file has comments containing one ";", the file will be split to two parts to be compute
And we get the error (ERROR - SLO configuration is empty) in the output :

INFO - Loading slo-generator config from config.yaml
INFO - Loading config from HTTP request
INFO - Batch request detected. Splitting body and sending individual requests separately.
INFO - Sending # Copyright 2019 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License") to HTTP batch handler.
INFO - Loading slo-generator config from config.yaml
INFO - Loading config from HTTP request
ERROR - SLO configuration is empty
INFO - Sending 
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#            http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
---
apiVersion: sre.google.com/v2
kind: ServiceLevelObjective

It is more standard and safer to use the yaml document markers as separator : https://yaml.org/spec/1.2.2/#document-markers

Currently, we can't send multiple yaml documents in one file with a standard way.

Thanks in advance for feedbacks.
Rgs,

[smehboub]

Hello @lvaylet

Any news please ?

Thanks in advance.
Rgs,

Sophian