def __init__(self, wsgi_app_reference, config: MetricsApiConfig):
"""
Constructs and initializes MetricsMiddleware WSGI middleware to be passed into
the currently running WSGI web server.
Args:
wsgi_app_reference ([type]): Reference to the current WSGI application,
which will be wrapped
config (MetricsApiConfig): Instance of MetricsApiConfig object
"""
self.config = config
self.app = wsgi_app_reference
self.metrics_core = Metrics(config)
class ReadMeMetrics:
def __init__(self, config: MetricsApiConfig, app: Flask = None):
self.config = config
self.metrics_core = Metrics(config)
if app is not None:
self.init_app(app)
def init_app(self, app: Flask):
self.config.LOGGER.info(
f"Configuring {app.name} hooks to call ReadMeMetrics extension functions"
)
app.before_request(self.before_request)
app.after_request(self.after_request)
def before_request(self):
try:
request.rm_start_dt = datetime.utcnow().strftime(
"%Y-%m-%dT%H:%M:%SZ")
request.rm_start_ts = int(time.time() * 1000)
if "Content-Length" in request.headers or request.data:
request.rm_content_length = request.headers[
"Content-Length"] or "0"
request.rm_body = request.data or ""
except Exception as e:
# Errors in the Metrics SDK should never cause the application to
# throw an error. Log it but don't re-raise.
self.config.LOGGER.exception(e)
def after_request(self, response):
try:
response_info = ResponseInfoWrapper(
response.headers,
response.status,
content_type=None,
content_length=None,
body=response.data,
)
self.metrics_core.process(request, response_info)
except Exception as e:
# Errors in the Metrics SDK should never cause the application to
# throw an error. Log it but don't re-raise.
self.config.LOGGER.exception(e)
finally:
return response
class MetricsMiddleware:
def __init__(self, get_response, config=None):
self.get_response = get_response
self.config = config or settings.README_METRICS_CONFIG
assert isinstance(self.config, MetricsApiConfig)
self.metrics_core = Metrics(self.config)
def __call__(self, request):
try:
request.rm_start_dt = str(datetime.utcnow())
request.rm_start_ts = int(time.time() * 1000)
if request.headers["Content-Length"] or request.body:
request.rm_content_length = request.headers[
"Content-Length"] or "0"
request.rm_body = request.body or ""
except Exception as e:
# Errors in the Metrics SDK should never cause the application to
# throw an error. Log it but don't re-raise.
self.config.LOGGER.exception(e)
response = self.get_response(request)
try:
try:
body = response.content.decode("utf-8")
except UnicodeDecodeError:
body = "[NOT VALID UTF-8]"
response_info = ResponseInfoWrapper(
response.headers,
response.status_code,
content_type=None,
content_length=None,
body=body,
)
self.metrics_core.process(request, response_info)
except Exception as e:
# Errors in the Metrics SDK should never cause the application to
# throw an error. Log it but don't re-raise.
self.config.LOGGER.exception(e)
finally:
return response
class MetricsMiddleware:
"""Core middleware class for ReadMe Metrics
Attributes:
config (MetricsApiConfig): Contains the configuration settings for the running
middleware instance
"""
def __init__(self, wsgi_app_reference, config: MetricsApiConfig):
"""
Constructs and initializes MetricsMiddleware WSGI middleware to be passed into
the currently running WSGI web server.
Args:
wsgi_app_reference ([type]): Reference to the current WSGI application,
which will be wrapped
config (MetricsApiConfig): Instance of MetricsApiConfig object
"""
self.config = config
self.app = wsgi_app_reference
self.metrics_core = Metrics(config)
def __call__(self, environ, start_response):
"""Method that is called by the running WSGI server.
You should NOT be calling this method yourself under normal circumstances.
"""
response_headers = {}
response_status = 0
iterable = None
req = Request(environ)
def _start_response(_status, _response_headers, *args):
write = start_response(_status, _response_headers, *args)
# Populate response info (headers & status)
nonlocal response_headers, response_status
response_headers = _response_headers
response_status = _status
return write
try:
req.rm_start_dt = str(datetime.datetime.now())
req.rm_start_ts = int(time.time() * 1000)
if req.method == "POST":
# The next 4 lines are a workaround for a serious shortcoming in the
# WSGI spec.
#
# The data can only be read once, after which the socket is exhausted
# and cannot be read again. As such, we read the data and then
# repopulate the variable so that it can be used by other code down the
# pipeline.
#
# For more info: https://stackoverflow.com/a/13106009/643951
# the environment variable CONTENT_LENGTH may be empty or missing
try:
content_length = int(environ.get("CONTENT_LENGTH", 0))
except (ValueError):
content_length = 0
content_body = environ["wsgi.input"].read(content_length)
# guarding check to close stream
if hasattr(environ["CONTENT_LENGTH"], "close"):
environ["wsgi.input"].close()
environ["wsgi.input"] = io.BytesIO(content_body)
req.rm_content_length = content_length
req.rm_body = content_body
iterable = self.app(environ, _start_response)
for data in iterable:
res_ctype = ""
res_clength = 0
htype = next(
(h for h in response_headers if h[0] == "Content-Type"),
None)
hlength = next(
(h for h in response_headers if h[0] == "Content-Length"),
None)
if htype and hlength:
res_ctype = htype[1]
res_clength = int(hlength[1])
# Populate response body
res = ResponseInfoWrapper(
response_headers,
response_status,
res_ctype,
res_clength,
data.decode("utf-8"),
)
# Send off data to be queued (and processed) by ReadMe if allowed
if self.config.ALLOWED_HTTP_HOSTS:
if environ["HTTP_HOST"] in self.config.ALLOWED_HTTP_HOSTS:
self.metrics_core.process(req, res)
else:
# If the allowed_http_hosts has not been set (None by default), send off the data to be queued
self.metrics_core.process(req, res)
yield data
finally:
# Undocumented in WSGI spec but the iterable has to be closed
if hasattr(iterable, "close"):
iterable.close()
def __init__(self, get_response, config=None):
self.get_response = get_response
self.config = config or settings.README_METRICS_CONFIG
assert isinstance(self.config, MetricsApiConfig)
self.metrics_core = Metrics(self.config)
def __init__(self, config: MetricsApiConfig, app: Flask = None):
self.config = config
self.metrics_core = Metrics(config)
if app is not None:
self.init_app(app)