configuration-layer 1.0.9

Initial configuration layer for microservices

# Initial configuration layer for Microservices



```json
_ _ _ _
| (_) | | (_)
__| |_ ___ ___| | __ _ _ _ __ ___ ___ _ __
/ _` | / __|/ __| |/ _` | | '_ ` _ \ / _ \ '__|
| (_| | \__ \ (__| | (_| | | | | | | | __/ |
\__,_|_|___/\___|_|\__,_|_|_| |_| |_|\___|_|


```

This service is in his early age. **DO NOT USE in production** or if you want to, please be aware you are going to use a piece of code which probably will be
changed or improved ( and not necessarily in this order) soon and very often. You have been warned!
This service requires at least another service listening to a few KAFKA topics.

# Service description

This service has been developed to be used as part of a multilayer microservice based infrastructure.
It provides services with a layer of functionalities to be used in order to request the needed configuration settings to start a service.
It uses KAFKA as messaging platform in order to exchange messages among services.
In order to be used it needs a service which acts as a **service-registry** that receive a request and send back a response.


# How to add it to your microservice

```python
from configuration_layer.service_setup.configuration_request import ConfigurationSeeker
from configuration_layer.utils.configuration_validation import validate_service_configuration
import configuration_layer.helpers.producer_messages as message
import sys, os
import datetime
from messaging_middleware.utils.logger import Logger



def check_configuration_directory():
service_configuration_directory = os.environ.get('service_configuration_directory', 'configuration')
if os.path.isdir(service_configuration_directory):
return os.getcwd() + service_configuration_directory
else:
return False


def seeker_request(**kwargs):
seeker = ConfigurationSeeker(consumer_topic='tcsetconf',
producer_topic='tcgetconf',
bootstrap_servers="your broker here",
schema_registry='your schema registry here',
message={"cmd": "get_conf", "auth": "ASC", "service_name": "myservicename"},
key_schema={"service_name": "myservicename"},
service_name='myservicename',
service_configuration_directory= os.environ.get('service_configuration_directory', 'configuration'),
breakable=kwargs.get('breakable', 1),
set=kwargs.get('set', 0)
)
seeker.start()
seeker.join()


if __name__ == "__main__":
if not check_configuration_directory():
sys.exit()

logger = Logger()
seeker_request()
if validate_service_configuration():
logger.logmsg('info', "==Configuration Completed==")
else:
message_to_produce = message.operation_result(service_name="myservicename",
last_operation='setconf',
timestamp=datetime.datetime.now(
datetime.timezone.utc).strftime(
'%Y-%m-%dT%H:%M:%S%z'),
operation_result=message.const_values()[
'CONFIGURATION_FILE_VALIDATION_ERROR'],
error_description='')

logger.produce_msg(message_to_produce)
logger.logmsg('error', "==CONFIGURATION_FILE_VALIDATION_ERROR==")
sys.exit()

```

# CONFLUENT KAFKA TOPIC:

The service send message to a predefined (hardcoded atm) topic, which has the following schema registry

**tcservicesmonitor-value** schema message
```
{
"schema": "{\"type\":\"record\",\"name\":\"key\",\"namespace\":\"example.avro\",\"fields\":[{\"name\": \"service_name\", \"type\": \"string\",\"default\": \"empty\"},{\"name\": \"last_operation\", \"type\": \"string\",\"default\": \"empty\"},{\"name\": \"timestamp\", \"type\": \"string\",\"default\": \"empty\"},{\"name\": \"operation_result\", \"type\":\"string\" },{\"name\": \"operation_description\", \"type\":\"string\" ,\"default\": \"empty\"},{\"name\": \"error_description\", \"type\":\"string\" ,\"default\": \"empty\"}]}"
}
```
```json
{
"type": "record",
"name": "key",
"namespace": "example.avro",
"fields": [
{
"name": "service_name",
"type": "string",
"default": "empty"
},
{
"name": "last_operation",
"type": "string",
"default": "empty"
},
{
"name": "timestamp",
"type": "string",
"default": "empty"
},
{
"name": "operation_result",
"type": "string"
},
{
"name": "operation_description",
"type": "string"
}
]
}
```
**tcservicesmonitor-key** schema message
```json

{
"type": "record",
"name": "key",
"namespace": "example.avro",
"fields": [
{
"name": "service_name",
"type": "string",
"default": "empty"
}
]
}
```

# Example of the message service sends to request the configuration

```json

{
"topic": "tcgetconf",
"value": {
"cmd": "get_conf",
"auth": "ASC",
"service_name": "myservicename"
}
}
```
# Example of a response

```json
{
"service_name": "myservicename",
"start_environment": "staging",
"datacentre": "",
"external_rest_services": {},
"persistence_conf": {},
"credentials": {}
}

```


License
-------
MIT License


Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.