class RestClient(IOpenable, IConfigurable, IReferenceable):
"""
Abstract client that calls remove endpoints using HTTP/REST protocol.
### Configuration parameters ###
- base_route: base route for remote URI
- connection(s):
- discovery_key: (optional) a key to retrieve the connection from IDiscovery
- protocol: connection protocol: http or https
- host: host name or IP address
- port: port number
- uri: resource URI or connection string with all parameters in it
- options:
- retries: number of retries (default: 3)
- connect_timeout: connection timeout in milliseconds (default: 10 sec)
- timeout: invocation timeout in milliseconds (default: 10 sec)
### References ###
- *:logger:*:*:1.0 (optional) ILogger components to pass log messages
- *:counters:*:*:1.0 (optional) ICounters components to pass collected measurements
- *:discovery:*:*:1.0 (optional) IDiscovery services to resolve connection
Example:
class MyRestClient(RestClient, IMyClient):
def get_data(self, correlation_id, id):
timing = self.instrument(correlationId, 'myclient.get_data')
result = self._controller.get_data(correlationId, id)
timing.end_timing()
return result
...
client = MyRestClient()
client.configure(ConfigParams.fromTuples("connection.protocol", "http",
"connection.host", "localhost",
"connection.port", 8080))
data = client.getData("123", "1")
...
"""
_default_config = None
_client = None
_uri = None
_timeout = 1000
_connection_resolver = None
_logger = None
_counters = None
_options = None
_base_route = None
_retries = 1
_headers = None
_connect_timeout = 1000
def __init__(self):
"""
Creates a new instance of the client.
"""
self._connection_resolver = HttpConnectionResolver()
self._default_config = ConfigParams.from_tuples(
"connection.protocol", "http", "connection.host", "0.0.0.0",
"connection.port", 3000, "options.timeout", 10000,
"options.request_max_size", 1024 * 1024, "options.connect_timeout",
10000, "options.retries", 3, "options.debug", True)
self._logger = CompositeLogger()
self._counters = CompositeCounters()
self._options = ConfigParams()
self._headers = {}
def set_references(self, references):
"""
Sets references to dependent components.
:param references: references to locate the component dependencies.
"""
self._logger.set_references(references)
self._counters.set_references(references)
self._connection_resolver.set_references(references)
def configure(self, config):
"""
Configures component by passing configuration parameters.
:param config: configuration parameters to be set.
"""
config = config.set_defaults(self._default_config)
self._connection_resolver.configure(config)
self._options.override(config.get_section("options"))
self._retries = config.get_as_integer_with_default(
"options.retries", self._retries)
self._connect_timeout = config.get_as_integer_with_default(
"options.connect_timeout", self._connect_timeout)
self._timeout = config.get_as_integer_with_default(
"options.timeout", self._timeout)
self._base_route = config.get_as_string_with_default(
"base_route", self._base_route)
def _instrument(self, correlation_id, name):
"""
Adds instrumentation to log calls and measure call time. It returns a Timing object that is used to end the time measurement.
:param correlation_id: (optional) transaction id to trace execution through call chain.
:param name: a method name.
:return: Timing object to end the time measurement.
"""
TYPE_NAME = self.__class__.__name__ or 'unknown-target'
self._logger.trace(correlation_id,
f"Calling {name} method {TYPE_NAME}")
self._counters.increment_one(f"{TYPE_NAME}.{name}.call_count")
return self._counters.begin_timing(f"{TYPE_NAME}.{name}.call_count")
def _instrument_error(self,
correlation_id,
name,
err,
result=None,
callback=None):
"""
Adds instrumentation to error handling.
:param correlation_id: (optional) transaction id to trace execution through call chain.
:param name: a method name.
:param err: an occured error
:param result: (optional) an execution result
:param callback: (optional) an execution callback
"""
if err is not None:
TYPE_NAME = self.__class__.__name__ or 'unknown-target'
self._logger.error(correlation_id, err,
f"Failed to call {name} method of {TYPE_NAME}")
self._counters.increment_one(f"{name}.call_errors")
if callback:
callback(err, result)
def is_opened(self):
"""
Checks if the component is opened.
:return: true if the component has been opened and false otherwise.
"""
return self._client is not None
def open(self, correlation_id):
"""
Opens the component.
:param correlation_id: (optional) transaction id to trace execution through call chain.
"""
if self.is_opened():
return
connection = self._connection_resolver.resolve(correlation_id)
self._uri = connection.get_uri()
self._client = requests
self._logger.debug(correlation_id,
"Connected via REST to " + self._uri)
def close(self, correlation_id):
"""
Closes component and frees used resources.
:param correlation_id: (optional) transaction id to trace execution through call chain.
"""
if self._client is not None:
self._logger.debug(correlation_id,
"Disconnected from " + self._uri)
self._client = None
self._uri = None
def _to_json(self, obj):
if obj is None:
return None
if isinstance(obj, set):
obj = list(obj)
if isinstance(obj, list):
result = []
for item in obj:
item = self._to_json(item)
result.append(item)
return result
if isinstance(obj, dict):
result = {}
for (k, v) in obj.items():
v = self._to_json(v)
result[k] = v
return result
if hasattr(obj, 'to_json'):
return obj.to_json()
if hasattr(obj, '__dict__'):
return self._to_json(obj.__dict__)
return obj
def fix_route(self, route) -> str:
if route is not None and len(route) > 0:
if route[0] != '/':
route = f'/{route}'
return route
return ''
def createRequestRoute(self, route):
builder = ''
if self._uri is not None and len(self._uri) > 0:
builder = self._uri
builder += self.fix_route(self._base_route)
if route[0] != '/':
builder += '/'
builder += route
return builder
def add_correlation_id(self, correlation_id=None, params=None):
params = params or {}
if not (correlation_id is None):
params['correlation_id'] = correlation_id
return params
def add_filter_params(self, params=None, filters=None):
params = params or {}
if not (filters is None):
params.update(filters)
return params
def add_paging_params(self, params=None, paging=None):
params = params or {}
if not (paging is None):
if not (paging['total'] is None):
params['total'] = paging['total']
if not (paging['skip'] is None):
params['skip'] = paging['skip']
if not (paging['take'] is None):
params['take'] = paging['take']
# params.update(paging)
return params
def call(self, method, route, correlation_id=None, params=None, data=None):
"""
Calls a remote method via HTTP/REST protocol.
:param method: HTTP method: "get", "head", "post", "put", "delete"
:param route: a command route. Base route will be added to this route
:param correlation_id: (optional) transaction id to trace execution through call chain.
:param params: (optional) query parameters.
:param data: (optional) body object.
:return: result object
"""
method = method.upper()
route = self.createRequestRoute(route)
params = self.add_correlation_id(correlation_id=correlation_id,
params=params)
response = None
result = None
try:
# Call the service
data = self._to_json(data)
response = requests.request(method,
route,
params=params,
json=data,
timeout=self._timeout)
except Exception as ex:
error = InvocationException(correlation_id, 'REST_ERROR',
'REST operation failed: ' +
str(ex)).wrap(ex)
raise error
if response.status_code == 404 or response.status_code == 204:
return None
try:
# Retrieve JSON data
result = response.json()
except:
# Data is not in JSON
if response.status_code < 400:
raise UnknownException(correlation_id, 'FORMAT_ERROR',
'Failed to deserialize JSON data: ' + response.text) \
.with_details('response', response.text)
else:
raise UnknownException(correlation_id, 'UNKNOWN', 'Unknown error occured: ' + response.text) \
.with_details('response', response.text)
# Return result
if response.status_code < 400:
return result
# Raise error
# Todo: We need to implement proper from_value method
error = ErrorDescription.from_json(result)
error.status = response.status_code
raise ApplicationExceptionFactory.create(error)
class RestService(IOpenable, IConfigurable, IReferenceable, IUnreferenceable,
IRegisterable):
"""
Abstract service that receives remove calls via HTTP/REST protocol.
### Configuration parameters ###
- base_route: base route for remote URI
- dependencies:
- endpoint: override for HTTP Endpoint dependency
- controller: override for Controller dependency
- connection(s):
- discovery_key: (optional) a key to retrieve the connection from IDiscovery
- protocol: connection protocol: http or https
- host: host name or IP address
- port: port number
- uri: resource URI or connection string with all parameters in it
### References ###
- *:logger:*:*:1.0 (optional) ILogger components to pass log messages
- *:counters:*:*:1.0 (optional) ICounters components to pass collected measurements
- *:discovery:*:*:1.0 (optional) IDiscovery services to resolve connection
- *:endpoint:http:*:1.0 (optional) HttpEndpoint reference
Example:
class MyRestService(RestService):
_controller = None
...
def __init__(self):
super(MyRestService, self).__init__()
self._dependencyResolver.put("controller", Descriptor("mygroup","controller","*","*","1.0"))
def set_references(self, references):
super(MyRestService, self).set_references(references)
self._controller = self._dependencyResolver.get_required("controller")
def register():
...
service = MyRestService()
service.configure(ConfigParams.from_tuples("connection.protocol", "http",
"connection.host", "localhost",
"connection.port", 8080))
service.set_references(References.from_tuples(Descriptor("mygroup","controller","default","default","1.0"), controller))
service.open("123")
"""
_default_config = None
_debug = False
_dependency_resolver = None
_logger = None
_counters = None
# _registered = None
_local_endpoint = None
_config = None
_references = None
_base_route = None
_endpoint = None
_opened = None
def __init__(self):
self._default_config = ConfigParams.from_tuples(
"base_route", None, "dependencies.endpoint",
"*:endpoint:http:*:1.0")
# self._registered = False
self._dependency_resolver = DependencyResolver()
self._logger = CompositeLogger()
self._counters = CompositeCounters()
def _instrument(self, correlation_id, name):
"""
Adds instrumentation to log calls and measure call time. It returns a Timing object that is used to end the time measurement.
:param correlation_id: (optional) transaction id to trace execution through call chain.
:param name: a method name.
"""
self._logger.trace(correlation_id, "Executing " + name + " method")
return self._counters.begin_timing(name + ".exec_time")
def set_references(self, references):
"""
Sets references to dependent components.
:param references: references to locate the component dependencies.
"""
self._references = references
self._logger.set_references(references)
self._counters.set_references(references)
self._dependency_resolver.set_references(references)
self._endpoint = self._dependency_resolver.get_one_optional('endpoint')
if self._endpoint is None:
self._endpoint = self.create_endpoint()
self._local_endpoint = True
else:
self._local_endpoint = False
self._endpoint.register(self)
def configure(self, config):
"""
Configures component by passing configuration parameters.
:param config: configuration parameters to be set.
"""
config = config.set_defaults(self._default_config)
self._config = config
self._dependency_resolver.configure(config)
self._base_route = config.get_as_string_with_default(
"base_route", self._base_route)
def unset_references(self):
"""
Unsets (clears) previously set references to dependent components.
"""
if not (self._endpoint is None):
self._endpoint.unregister(self)
self._endpoint = None
def create_endpoint(self):
endpoint = HttpEndpoint()
if not (self._config is None):
endpoint.configure(self._config)
if not (self._references is None):
endpoint.set_references(self._references)
return endpoint
def _instrument(self, correlation_id, name):
self._logger.trace(correlation_id, f"Executing {name} method")
self._counters.increment_one(f"{name}.exec_count")
return self._counters.begin_timing(f"{name}.exec_time")
def _instrument_error(self, correlation_id, name, error, result, callback):
if not (error is None):
self._logger.error(correlation_id, error,
f"Failed to execute {name} method")
self._counters.increment_one(f"{name}.exec_error")
if not (callback is None):
callback(error, result)
def is_opened(self):
"""
Checks if the component is opened.
:return: true if the component has been opened and false otherwise.
"""
return self._opened
def open(self, correlation_id):
"""
Opens the component.
:param correlation_id: (optional) transaction id to trace execution through call chain.
"""
if self.is_opened():
return
if self._endpoint is None:
self._endpoint = self.create_endpoint()
self._endpoint.register(self)
self._local_endpoint = True
if self._local_endpoint:
self._endpoint.open(correlation_id)
self._opened = True
# # register route
# if self._registered != True:
# self.add_route()
# self._registered = True
def close(self, correlation_id):
"""
Closes component and frees used resources.
:param correlation_id: (optional) transaction id to trace execution through call chain.
"""
if not self._opened:
return
if self._endpoint is None:
raise InvalidStateException(correlation_id, "NO_ENDPOINT",
"HTTP endpoint is missing")
if self._local_endpoint:
self._endpoint.close(correlation_id)
self._opened = False
def send_result(self, result):
"""
Creates a callback function that sends result as JSON object. That callack function call be called directly or passed as a parameter to business logic components.
If object is not null it returns 200 status code. For null results it returns
204 status code. If error occur it sends ErrorDescription with approproate status code.
:param result: a body object to result.
:return: execution result.
"""
return HttpResponseSender.send_result(result)
def send_created_result(self, result):
"""
Creates a callback function that sends newly created object as JSON. That callack function call be called directly or passed as a parameter to business logic components.
If object is not null it returns 201 status code. For null results it returns
204 status code. If error occur it sends ErrorDescription with approproate status code.
:param result: a body object to result.
:return: execution result.
"""
return HttpResponseSender.send_created_result(result)
def send_deleted_result(self):
"""
Creates a callback function that sends newly created object as JSON. That callack function call be called directly or passed as a parameter to business logic components.
If object is not null it returns 200 status code. For null results it returns
204 status code. If error occur it sends ErrorDescription with approproate status code.
:return: execution result.
"""
return HttpResponseSender.send_deleted_result()
def send_error(self, error):
"""
Sends error serialized as ErrorDescription object and appropriate HTTP status code. If status code is not defined, it uses 500 status code.
:param error: an error object to be sent.
"""
return HttpResponseSender.send_error(error)
def fix_route(self, route) -> str:
if (route is not None and len(route) > 0):
if (route[0] != '/'):
route = f'/{route}'
return route
return ''
def register_route(self, method, route, schema, handler):
"""
Registers an action in this objects REST server (service) by the given method and route.
:param method: the HTTP method of the route.
:param route: the route to register in this object's REST server (service).
:param schema: the schema to use for parameter validation.
:param handler: the action to perform at the given route.
"""
if self._endpoint is None:
return
route = f"{self.fix_route(self._base_route)}{self.fix_route(route)}"
# if not (self._base_route is None) and len(self._base_route) > 0:
# base_route = self._base_route
# if base_route[0] != '/':
# base_route = '/' + base_route
# if route[0] != '/':
# base_route = base_route + '/'
# route = base_route + route
self._endpoint.register_route(method, route, schema, handler)
def register(self):
pass
def get_data(self):
data = bottle.request.json
if isinstance(data, str):
return json.loads(bottle.request.json)
elif bottle.request.json:
return bottle.request.json
else:
return None
def get_request_param(self):
if (not (bottle is None)) and (not (bottle.request is None)) and (
not (bottle.request.params is None)):
return bottle.request.params
else:
return {}
def _append_base_route(self, route):
route = route or ''
if self._base_route is not None and len(self._base_route) > 0:
base_route = self._base_route
if base_route[0] != '/':
base_route = '/' + base_route
route = base_route + route
return route
def register_route_with_auth(self, method, route, schema, authorize,
action):
"""
Registers a route with authorization in HTTP endpoint.
:param method: HTTP method: "get", "head", "post", "put", "delete"
:param route: a command route. Base route will be added to this route
:param schema: a validation schema to validate received parameters.
:param authorize: an authorization interceptor
:param action: an action function that is called when operation is invoked.
"""
if self._endpoint is None:
return
route = self._append_base_route(self.fix_route(route))
self._endpoint.register_route_with_auth(method, route, schema,
authorize, method)
def register_interceptor(self, route, action):
"""
Registers a middleware for a given route in HTTP endpoint.
:param route: a command route. Base route will be added to this route
:param action: an action function that is called when middleware is invoked.
"""
if self._endpoint is None:
return
route = self._append_base_route(self.fix_route(route))
self._endpoint.register_interceptor(route, action)
class DirectClient(IConfigurable, IReferenceable, IOpenable):
"""
Abstract client that calls controller directly in the same memory space. It is used when multiple microservices are deployed in a single container (monolyth) and communication between them can be done by direct calls rather then through the network.
### Configuration parameters ###
- dependencies:
- controller: override controller descriptor
### References ###
- *:logger:*:*:1.0 (optional) ILogger components to pass log messages
- *:counters:*:*:1.0 (optional) ICounters components to pass collected measurements
- *:controller:*:*:1.0 controller to call business methods
Example:
class MyDirectClient(DirectClient, IMyClient):
def __init__(self):
super(MyDirectClient, self).__init__()
self._dependencyResolver.put('controller', Descriptor("mygroup", "controller", "*", "*", "*"))
...
def get_data(self, correlation_id, id):
timing = self.instrument(correlationId, 'myclient.get_data')
result = self._controller.get_data(correlationId, id)
timing.end_timing()
return result
client = MyDirectClient()
client.set_references(References.from_tuples(Descriptor("mygroup","controller","default","default","1.0"), controller))
data = client.get_data("123", "1")
...
"""
_controller = None
_opened = True
_logger = None
_counters = None
_dependency_resolver = None
def __init__(self):
"""
Creates a new instance of the client.
"""
self._logger = CompositeLogger()
self._counters = CompositeCounters()
self._dependency_resolver = DependencyResolver()
self._dependency_resolver.put('controller', 'none')
def configure(self, config):
"""
Configures component by passing configuration parameters.
:param config: configuration parameters to be set.
"""
self._dependency_resolver.configure(config)
def set_references(self, references):
"""
Sets references to dependent components.
:param references: references to locate the component dependencies.
"""
self._logger.set_references(references)
self._counters.set_references(references)
self._dependency_resolver.set_references(references)
self._controller = self._dependency_resolver.get_one_required('controller')
def _instrument(self, correlation_id, name):
"""
Adds instrumentation to log calls and measure call time. It returns a Timing object that is used to end the time measurement.
:param correlation_id: (optional) transaction id to trace execution through call chain.
:param name: a method name.
:return: Timing object to end the time measurement.
"""
self._logger.trace(correlation_id, f"Executing {name} method")
return self._counters.begin_timing(f"{name} .call_time")
def _instrument_error(self, correlation_id, name, err, result, callback):
"""
Adds instrumentation to error handling.
:param correlation_id: (optional) transaction id to trace execution through call chain.
:param name: a method name.
:param err: an occured error
:param result: (optional) an execution result
:param callback: (optional) an execution callback
"""
if err is not None:
self._logger.error(correlation_id, err, f'Failed to call {name} method')
self._counters.increment_one(f"{name}.call_errors")
if callback:
callback(err, result)
def is_opened(self):
"""
Checks if the component is opened.
:return: true if the component has been opened and false otherwise.
"""
return self._opened
def open(self, correlation_id):
"""
Opens the component.
:param correlation_id: (optional) transaction id to trace execution through call chain.
"""
if self._opened:
return
if self._controller is None:
raise ConnectionException(correlation_id, 'NO_CONTROLLER', 'Controller references is missing')
self._opened = True
self._logger.info(correlation_id, 'Opened direct client')
def close(self, correlation_id):
"""
Closes component and frees used resources.
:param correlation_id: (optional) transaction id to trace execution through call chain.
"""
if self._opened:
self._logger.info(correlation_id, 'Closed direct client')
self._opened = False