Añadir soporte para métricas (#62)

* Add metrics support out of the box

* Split to ease modularization

* Add logger metrics

* Add requirements

* Update pipfile lock

* Delete unnecesary line

* Deacoplate class of logger function

* Deacoplate logger metrics from metrics

* Delete unused imported functions

* Create metrics test

* Fix vulnerable dependencies

* Test metrics endpoint

* Restore deleted line

* Migrate metrics implementation to service

* Add metrics documentation

* Add jaeger metrics

* Don't use namespace for metrics

See jaegertracing/jaeger-client-python#268

* Add jaeger metrics test

Author: alexppg

Pipfile

@@ -14,6 +14,7 @@ jaeger-client = "==4.1.0"
 flask-opentracing = "*"
 opentracing = ">=2.1"
 opentracing-instrumentation = "==3.2.1"
+prometheus_client = ">=0.7.1"
 [dev-packages]
 requests-mock = "*"
 coverage = "==4.4.0"

Pipfile.lock

@@ -14,7 +14,27 @@ Extends the Microservice with [Connexion](https://github.com/zalando/connexion)
 Extend the [requests library](http://docs.python-requests.org/en/master/) with trace headers and parsing JSON objects.
 Encapsulate common rest operations between business services propagating trace headers if set up.
 
+## Metrics
+Adds ![Prometheus](https://prometheus.io/) metrics using the ![Prometheus Client
+Library](https://github.com/prometheus/client_python).
+
+At the moment, the next metrics are available:
+- Incoming requests latency as a histogram
+- Incoming requests number as a counter, divided by HTTP method, endpoint and
+  HTTP status
+- Total number of log events divided by level
+- If `tracer` service activated and it's jaeger, it will show its metrics
+
+To use this service, you may add the next to you configuration file:
+
+```yaml
+pyms:
+  metrics: true
+```
+
+This will add the endpoint `/metrics` to your microservice, which will expose
+the metrics.
 
 ## How to contrib: create your own service:
 
-TODO
+TODO

docs/services.md

@@ -8,7 +8,7 @@ With the function `create_app` initialize the Flask app, register [blueprints](h
 and initialize all libraries such as Swagger, database, trace system, custom logger format, etc.
 
 ### pyms/flask/services
-Integrations and wrappers over common libs like request, swagger, connexion
+Integrations and wrappers over common libs like request, swagger, connexion or metrics.
 
 ### pyms/flask/healthcheck
 This view is usually used by Kubernetes, Eureka and other systems to check if our application is running.
@@ -17,4 +17,4 @@ This view is usually used by Kubernetes, Eureka and other systems to check if ou
 Print logger in JSON format to send to server like Elasticsearch. Inject span traces in logger.
 
 ### pyms/tracer
-Create an injector `flask_opentracing.FlaskTracer` to use in our projects.
+Create an injector `flask_opentracing.FlaskTracer` to use in our projects.

docs/structure.md

@@ -70,6 +70,7 @@ def init_logger(self):
         log_handler.setFormatter(formatter)
 
         self.application.logger.addHandler(log_handler)
+
         self.application.logger.propagate = False
 
         if self.application.config["DEBUG"]:
@@ -99,6 +100,15 @@ def init_app(self) -> Flask:
 
         return application
 
+    def init_metrics(self):
+        if getattr(self, "metrics", False) and self.metrics:
+            self.application.register_blueprint(self.metrics.metrics_blueprint)
+            self.metrics.add_logger_handler(
+                self.application.logger,
+                self.application.config["APP_NAME"]
+            )
+            self.metrics.monitor(self.application)
+
     def create_app(self):
         """Initialize the Flask app, register blueprints and initialize
         all libraries like Swagger, database,
@@ -121,6 +131,8 @@ def create_app(self):
 
         self.init_logger()
 
+        self.init_metrics()
+
         return self.application
 
     def add_error_handlers(self):

pyms/flask/app/create_app.py

@@ -0,0 +1,71 @@
+import time
+import logging
+
+from flask import Blueprint, Response, request
+from prometheus_client import Counter, Histogram, generate_latest
+from pyms.flask.services.driver import DriverService
+
+# Based on https://github.com/sbarratt/flask-prometheus
+# and https://github.com/korfuri/python-logging-prometheus/
+
+FLASK_REQUEST_LATENCY = Histogram(
+    "flask_request_latency_seconds", "Flask Request Latency", ["method", "endpoint"]
+)
+FLASK_REQUEST_COUNT = Counter(
+    "flask_request_count", "Flask Request Count", ["method", "endpoint", "http_status"]
+)
+
+LOGGER_TOTAL_MESSAGES = Counter(
+    "python_logging_messages_total",
+    "Count of log entries by service and level.",
+    ["service", "level"],
+)
+
+
+def before_request():
+    request.start_time = time.time()
+
+
+def after_request(response):
+    request_latency = time.time() - request.start_time
+    FLASK_REQUEST_LATENCY.labels(request.method, request.path).observe(request_latency)
+    FLASK_REQUEST_COUNT.labels(request.method, request.path, response.status_code).inc()
+
+    return response
+
+
+class Service(DriverService):
+    service = "metrics"
+
+    def __init__(self, service, *args, **kwargs):
+        super().__init__(service, *args, **kwargs)
+        self.metrics_blueprint = Blueprint("metrics", __name__)
+        self.serve_metrics()
+
+    def monitor(self, app):
+        app.before_request(before_request)
+        app.after_request(after_request)
+
+    def serve_metrics(self):
+        @self.metrics_blueprint.route("/metrics", methods=["GET"])
+        def metrics():
+            return Response(
+                generate_latest(),
+                mimetype="text/print()lain",
+                content_type="text/plain; charset=utf-8",
+            )
+
+    def add_logger_handler(self, logger, service_name):
+        logger.addHandler(MetricsLogHandler(service_name))
+        return logger
+
+
+class MetricsLogHandler(logging.Handler):
+    """A LogHandler that exports logging metrics for Prometheus.io."""
+
+    def __init__(self, app_name):
+        super(MetricsLogHandler, self).__init__()
+        self.app_name = app_name
+
+    def emit(self, record):
+        LOGGER_TOTAL_MESSAGES.labels(self.app_name, record.levelname).inc()

pyms/flask/services/metrics.py

@@ -1,8 +1,11 @@
 import logging
 
+from jaeger_client.metrics.prometheus import PrometheusMetricsFactory
+
 from pyms.constants import LOGGER_NAME
 from pyms.flask.services.driver import DriverService
 from pyms.utils.utils import check_package_exists, import_package, import_from
+from pyms.config.conf import get_conf
 
 logger = logging.getLogger(LOGGER_NAME)
 
@@ -43,7 +46,11 @@ def init_jaeger_tracer(self):
                     'reporting_host': self.host
                 }
             }
-
+        metrics_config = get_conf(service="pyms.metrics", empty_init=True, memoize=False)
+        metrics = ""
+        if metrics_config:
+            service_name = self.component_name.lower().replace("-", "_").replace(" ", "_")
+            metrics = PrometheusMetricsFactory()
         config = Config(config={
             **{'sampler': {
                 'type': 'const',
@@ -54,6 +61,7 @@ def init_jaeger_tracer(self):
             },
             **host
         }, service_name=self.component_name,
+            metrics_factory=metrics,
             validate=True)
         return config.initialize_tracer()
 

pyms/flask/services/tracer.py

@@ -42,7 +42,7 @@ mkdocs==1.0.4
 mock==2.0.0
 more-itertools==7.2.0
 nose==1.3.7
-numpy==1.13.3
+numpy==1.16.1
 openapi-spec-validator==0.2.8
 opentracing==2.2.0
 opentracing-instrumentation==3.2.1
@@ -52,7 +52,7 @@ pkginfo==1.5.0.1
 pluggy==0.13.0
 protobuf==3.9.0rc1
 py==1.8.0
-py-ms==1.0.0
+py-ms==1.0.1
 Pygments==2.3.1
 pylint==2.4.3
 pyparsing==2.4.2
@@ -85,3 +85,4 @@ webencodings==0.5.1
 Werkzeug==0.16.0
 wrapt==1.11.2
 zipp==0.6.0
+prometheus_client==0.7.1

requirements-tests.txt

@@ -0,0 +1,11 @@
+---
+pyms:
+  metrics: true
+  tracer:
+    client: "jaeger"
+    component_name: "Python Microservice"
+my-ms:
+  DEBUG: true
+  TESTING: true
+  APP_NAME: "Python Microservice"
+  APPLICATION_ROOT: /

tests/config-tests-metrics.yml

@@ -1,4 +1,5 @@
 pyms:
+  metrics: true
   requests:
     data: data
   swagger:
@@ -17,4 +18,4 @@ my-ms:
   subservice1:
      test: input
   subservice2:
-     test: output
+     test: output