microservices-connector 0.1.4

Inter-Service communication framework, support for microservice architecture and distributed system via http

Microservices Connector
=======================

Microservices Connector is a Inter-Service communication framework,
support for microservice architecture and distributed system.

Getting Started
---------------

**Microservices** is a way of breaking large software projects into
loosely coupled modules, which communicate with each other through
simple APIs. The advantages of microservices are improves fault
isolation, scalability, Ease of development. It convinced some big
enterprise players – like Amazon, Netflix, and eBay – to begin their
transitions.

*Microservices Connector* is a Inter-Service communication framework
written in python, support for microservice architecture and distributed
system. Its features contain: \* Transfering data as returning a
function results or quering data. \* Support transfer multiple values
with many type as string, int, float, list, dict, class attribute \* Do
not require knowledge about web/http connection or touch to them \*
Distributed system

.. figure:: images/Distributed-system.jpeg
:alt: Illustration of network system. Source:medium.com

alt text

Illustration of network system. Source:medium.com

As illustration, distributed systems are very stable and Infinite
scalability. But distributed systems are the most difficult to maintain

Quickstart:
~~~~~~~~~~~

Microservices Connector is available on pip. You can install via pip
(require python>=3.5):

::

pip install microservices_connector

Start project by a minimum example:

- Step 1: Create 1 file name app1.py, write and save with the code
below

::

from microservices_connector.Interservices import Microservice

M = Microservice(__name__)

@M.typing('/helloworld')
@M.reply
def helloworld(name):
return 'Welcome %s' % (name)

if __name__ == '__main__':
M.run()

- Step 2: Create 1 file name app2.py, write and save with the code
below \`\`\` from microservices\_connector.Interservices import
Friend

F = Friend('app1', 'http://0.0.0.0:5000') message =
F.send('/helloworld','Mr. Developer') print(message)

::

* Step 3: Run app1.py and app2.py together.

Open a terminal in the same folder with them and run:
`python app1.py`.

Open another terminal in the same folder and run:
`python app2.py`

You get the result: `Welcome Mr. Developer` in terminal of app2.py. This is no difference if you do `from .app1 import helloword; message = helloworld('Mr. Developer'); print(message)`. Note: To stop app1, open its terminal and Ctrl + C. The example can be found in `test/example00` folder

**Explanation**: App1 and app2 are small example of microservice system. In the example, **M** in app1 is listener, a http server while __F__ in app2 is sender. Listener and sender are isolated design, they can work seperately or together in an app/service. A microservice can be a listener of many other microservices or sender of many other microservices or both of them. A standard microservice mention in this project contain both listener and sender.

## Tutorial

### 1. Start your first app

In the tutorial, we assume you have this code in the top of your file.

from microservices\_connector.Interservices import Microservice

M = Microservice(\ **name**)

::

Now, look closer at `Microservice(__name__)`, it actually look like this:

Microservice(name, port: int=5000, host: str='0.0.0.0', debug=None, token: dict = {}, secretKey=None)

Arguments:
* name {str} -- Require a name for your app, recommend put `__name__` for it
* port {int} -- Choose from 3000 to 9000, default to 5000
* host {str} -- Host ip, Default 0.0.0.0 for localhost
* debug {boolean} -- True for development, False/None for production
* token {dict} -- A dict contain all rule and its token. It can be set later

The class Microservice is used to create a listener/a microservice. In a file/app, you should only have one listener. About parameters, If you aren't familiar with http server, you only need remember:
* One app should have only one listener
* Should use `__name__` for name and name need to be unique
* If you run multiple listener, use only one unique port for each listener. for example:

M1 = Microservice(\ **name**, port=5010) # in file app1 M2 =
Microservice(\ **name**, port=5020) # in file app2

::

Note: You should be carefully if there are other web applications running in your port/server.

### 2. Way of running an app

A sender is a python def, so you can put it anywhere in your app. Listener is a http server so it's a bit difference from other.

Option 1: Use if/main in the end of startup file (file that you start your project by `python <filename>`). Add the following code the end:

M is your Microservice Object
=============================

if **name** == '**main**': M.run()

::


Option 2: Create a file name run.py and run your app from this file. For example, we create a run.py in the same folder of app1.py in the first example. It will be like this:

from app1 import M

if **name** == '**main**': M.run(port=5000, host='0.0.0.0', debug=True)

::

Option 2 is more appreciated. It avoid the app looping from them self, so get away of stunning your app. If you have 2 app in a server/computer, you should create 2 run file for it. Don't for get `Ctrl + C` to stop your app.

Note: _We assume you already use one of the options above for your code_. This tutorial focuses on communication between 'service-to-service' as def function, not http connect.

### 3. Send, Typing and reply

Think like a human, if you want to communicate with some friend in facebook, you will open *messenger*, find your friend and send a message to them. It's a way of sending message to each other. Then, your friend will type a message and reply you. The process is similar here. See the code:

F = Friend('Corgi', 'http://0.0.0.0:5000') # this is: you're finding
friend in your head. # You can call him with a cute name like
'Puppy','Teddy' or 'Corgi'. # But you must always remember his real-name
is 'http://0.0.0.0:5000' to know actually who he is

message = F.send('/helloworld','Mr. Close friend') # then you can send
him a message

::


`/helloworld` is the rule/topic you say/ask to a friend or the route in http. It need to start with `/`. The rule must match with the rule of `Typing` to be replied. `Mr. Close friend` is what you are talking about, which can be string, integer, float, list, dict or class. For example: `F.send('/topic',variable1, variable2, keyword1='secret key')`

In other side, your friend or a microservice or a listener has the following process:

@M.typing('/helloworld') # this is the rule/topic he knows. If he don't
know, he cannot reply @M.reply # he is replying def helloworld(name): #
this is the process in side his head return 'Welcome %s' % (name) # the
answer

::


`@M.typing` - The rule/topic must exactly match with the topic was sent and should startwith "/". The `@M.reply` must come before def. Then, Microservice handles the remain. Next chapter is about returning data

### 4. Send and reply string, integer, float

In the sender side, you can send data type as the code below:

print( """############################## Test return string """) F =
Friend('app1', 'http://localhost:5000') print('Test: return a simple
string') x = F.send('/str', 'A variable value', key='A keyword variable
value') print('x=', x, type(x)) print('==========================')
print('Test: return multiple string') x, y, z = F.send('/str2', 'A
variable value', key='A keyword variable value') print('x=' ,x, type(x))
print('y=', y, type(y)) print('z=', z, type(z))

print( """############################## Test return a int, float """) F
= Friend('app1', 'http://localhost:5000') print('Test: return a simple
Value') x = F.send('/int', 2018, key=312) print('x=', x, type(x))
print('==========================') print('Test: return a simple Value')
x = F.send('/float', 2.018, key=3.12) print('x=', x, type(x))
print('==========================') print('Test: return multiple Value')
x, y, z = F.send('/int3', 3.1427, key=1000000000) print('x=', x,
type(x)) print('y=', y, type(y)) print('z=', z, type(z))

::

In the listener, you can reply/return data type as string, integer, float as below:

run a normal function in python
===============================

print('one cat here')

return string
=============

@M.typing('/str') @M.reply def string1(a,key): return a+'-'+key

return multiple string
======================

@M.typing('/str2') @M.reply def string2(a, key): return a, key,
a+'-'+key

return Integer and float
========================

@M.typing('/int') @M.reply def int1(a, key): return a+key

@M.typing('/float') @M.reply def float2(a, key): return a+key

@M.typing('/int3') @M.reply def int3(a, key): return a+key, key\ *key,
a*\ a

::

After that, first run listener then run sender. We have results (see example01):

Test: return a simple string x= A variable value-A keyword variable
value ========================== Test: return multiple string x= A
variable value y= A keyword variable value z= A variable value-A keyword
variable value 'testStr' 23.17 ms Test: return a simple Value x= 2330
========================== Test: return a simple Value x= 5.138
========================== Test: return multiple Value x=
1000000003.1427 y= 1000000000000000000 z= 9.87656329

::

Note: print('one cat here') print in the screen of listener. You can run any other python function, python code as normal in listener.

### 5. Send and reply list, dict

In the sender side, you can send data type as the code below:

print( """############################## Test return a list, dict """) F
= Friend('app1', 'http://localhost:5000') print('Test: return a simple
Value') x = F.send('/list', [12,34,45], key=['abc','zyz']) print('x=',
x, type(x)) print('==========================') print('Test: return a
simple Value') x = F.send('/dict', {'keyword':['anything']},
key={'int':20,'str':'adfafsa','float':0.2323}) print('x=', x, type(x))
print('==========================') print('Test: return multiple Value')
x, y, z = F.send('/list3', {'keyword': ['anything']}, key=['abc',
'zyz']) print('x=', x, type(x)) print('y=', y, type(y)) print('z=', z,
type(z))

::

In the listener, you can reply/return data type as string, integer, float as below:

test return list and dict
=========================

@M.typing('/list') @M.reply def list1(a, key): a.extend(key) return a

@M.typing('/dict') @M.reply def dict1(a, key): key['dict'] = a return
key

@M.typing('/list3') @M.reply def list3(a, key): key.append('other
value') c = None return a, key, c

::

After that, first run listener then run sender. We have results (for full example see tests/example01):

Test: return a simple Value x= [12, 34, 45, 'abc', 'zyz']
========================== Test: return a simple Value x= {'dict':
{'keyword': ['anything']}, 'float': 0.2323, 'int': 20, 'str': 'adfafsa'}
========================== Test: return multiple Value x= {'keyword':
['anything']} y= ['abc', 'zyz', 'other value'] z= None 'testListDict'
22.19 ms

::


### 6. Send and reply void, Nonetype, class attributes and use of token
In the sender side, you can send data type as the code below:

print( """############################## Test return NoneType, Class,
use of Token """) F = Friend('app1', 'http://localhost:5000')
print('Test: return a simple Value') x = F.send('/None', [12, 34, 45],
key=['abc', 'zyz']) print('x=', x, type(x))
print('==========================') print('Test: return a simple Value
with token') F.setRule('/class', token='123456') x = F.send('/class',
{'keyword': ['anything']}, key={'int': 20, 'str': 'adfafsa', 'float':
0.2323}) print('x=', x, type(x)) print('==========================')
print('Test: return multiple Value') F.setRule('/class2',
token='123456') x,y,z = F.send('/class2', {'keyword': ['anything']},
key={'int': 20, 'str': 'adfafsa', 'float': 0.2323}) print('x=', x,
type(x)) print('y=', y, type(y)) print('z=', z, type(z))

Test send class and list of class object
========================================

print(':raw-latex:`\n `Test: send class and list of class object')
F.setRule('/class3', token='123456') t1 = testservice('value1') t2 =
testservice('value2') x, y, z = F.send('/class3', [t1,t2], key={'t1':
t1, 't2': t2, 'list': [t1, t2]}) print('x=', x, type(x)) print('y=', y,
type(y)) print('z=', z, type(z))

::


In the listener, you can reply/return data type as string, integer, float as below:

return None, class Object
=========================

@M.typing('/None') @M.reply def TestNoneValue(a, key): key.append('Do
something in the server')

class testservice(object): name = 'test' Purpose = 'For test only' empty
= None def **init**\ (self, value): self.value = value

::

def onemethod(self):
pass

@M.typing('/class',token='123456') @M.reply def TestClass(a, key): t =
testservice(a) return t

@M.typing('/class2', token='123456') @M.reply def TestClass2(a, key): t
= testservice(key) return t, a, None

@M.typing('/class3', token='123456') @M.reply def TestClass3(a, key): x
= testservice(key) y = testservice(a) z = [y,x] return x, y, z

::

After that, first run listener then run sender. We have results (for full example see tests/example01):

Test return NoneType, Class, use of Token

Test: return a simple Value x= None ========================== Test:
return a simple Value with token x= {'Purpose': 'For test only',
'empty': None, 'name': 'test', 'value': {'keyword': ['anything']}}
========================== Test: return multiple Value x= {'Purpose':
'For test only', 'empty': None, 'name': 'test', 'value': {'float':
0.2323, 'int': 20, 'str': 'adfafsa'}} y= {'keyword': ['anything']} z=
None

Test: send class and list of class object x= {'Purpose': 'For test
only', 'empty': None, 'name': 'test', 'value': {'list': [{'Purpose':
'For test only', 'empty': None, 'name': 'test', 'value': 'value1'},
{'Purpose': 'For test only', 'empty': None, 'name': 'test', 'value':
'value2'}], 't1': {'Purpose': 'For test only', 'empty': None, 'name':
'test', 'value': 'value1'}, 't2': {'Purpose': 'For test only', 'empty':
None, 'name': 'test', 'value': 'value2'}}} y= {'Purpose': 'For test
only', 'empty': None, 'name': 'test', 'value': [{'Purpose': 'For test
only', 'empty': None, 'name': 'test', 'value': 'value1'}, {'Purpose':
'For test only', 'empty': None, 'name': 'test', 'value': 'value2'}]} z=
[{'Purpose': 'For test only', 'empty': None, 'name': 'test', 'value':
[{'Purpose': 'For test only', 'empty': None, 'name': 'test', 'value':
'value1'}, {'Purpose': 'For test only', 'empty': None, 'name': 'test',
'value': 'value2'}]}, {'Purpose': 'For test only', 'empty': None,
'name': 'test', 'value': {'list': [{'Purpose': 'For test only', 'empty':
None, 'name': 'test', 'value': 'value1'}, {'Purpose': 'For test only',
'empty': None, 'name': 'test', 'value': 'value2'}], 't1': {'Purpose':
'For test only', 'empty': None, 'name': 'test', 'value': 'value1'},
't2': {'Purpose': 'For test only', 'empty': None, 'name': 'test',
'value': 'value2'}}}] 'testClassType' 19.20 ms \`\`\` A Detail User
Guide will comming soon... ## Pros vs Cons and question From my opinion
only, Microservice connector has the following Pros and Cons to improve
### Pros: \* Ease of use, Ease of development, you don't need to touch
on http connection \* Can build decentralize or Distributed system with
Infinite scalability \* Send and receive data with many types as string,
int, float, list, dict. \* Connect all around the world with internet

Cons:
~~~~~

- Do not support send/receive tuple and set type (because I don't like
them).
- Do not support send/receive a whole class, return of decorator and
server-side computer
- Is not really fast log-broker server as RabbitMQ, ZeroMQ, kafka:
*yes, oneService cannot send 10 million message per second like them,
but it has other advance.*
- Do not support Database, user/role management, system manager: *not
yet, we are trying to write new feature include them. We welcome any
contributor support us.*

Question:
~~~~~~~~~

- Why not a load balancer ?

*It is out of range. Load balancer cover the other layer. Other
package can handle it better. But we consider to add a custom
function for it.*

- What about support more options, async/await ?

*We are trying to connect by Sanic and Japronto soon*

- What about data integrity, blockchain, token ?

*We are trying to add them, but cannot be soon*

Authors
-------

- **Tuan Nguyen Minh** - *Financer and Developer* - email:
[e-mail]

Thank for the framework and its authors: \* flask - micro webframework
\* requests

Favourite idioms: \* Don't repeat your self \* Think like human, make
for human \* Simple is stronger ## License: BDS license