Merge branch 'STF678_Task1_2_3_4' into 'STF678_Task_5_TTF_T043'

        - /{{.SandboxName}}/{{.MepName}}/service-apis

        - /{{.SandboxName}}/{{.MepName}}/published-apis

        - /{{.SandboxName}}/{{.MepName}}/capif-events

        - /{{.SandboxName}}/{{.MepName}}/eecs-serviceprovisioning

        - /{{.SandboxName}}/{{.MepName}}/eees-eecregistration

        - /{{.SandboxName}}/{{.MepName}}/eees-easdiscovery

        {{- else }}

        - /{{.SandboxName}}/mec_app_support

        - /{{.SandboxName}}/mec_service_mgmt

        - /{{.SandboxName}}/service-apis

        - /{{.SandboxName}}/published-apis

        - /{{.SandboxName}}/capif-events

        - /{{.SandboxName}}/eecs-serviceprovisioning

        - /{{.SandboxName}}/eees-eecregistration

        - /{{.SandboxName}}/eees-easdiscovery

        {{- end }}

  annotations:

    kubernetes.io/ingress.class: nginx

      rewrite ^/{{ .SandboxName }}/{{.MepName}}/service-apis(/|$)(.*)$ /service-apis/$2 break;

      rewrite ^/{{ .SandboxName }}/{{.MepName}}/published-apis(/|$)(.*)$ /published-apis/$2 break;

      rewrite ^/{{ .SandboxName }}/{{.MepName}}/capif-events(/|$)(.*)$ /capif-events/$2 break;

      rewrite ^/{{ .SandboxName }}/{{.MepName}}/eecs-serviceprovisioning(/|$)(.*)$ /eecs-serviceprovisioning/$2 break;

      rewrite ^/{{ .SandboxName }}/{{.MepName}}/eees-eecregistration(/|$)(.*)$ /eees-eecregistration/$2 break;

      rewrite ^/{{ .SandboxName }}/{{.MepName}}/eees-easdiscovery(/|$)(.*)$ /eees-easdiscovery/$2 break;

    {{- else }}

    nginx.ingress.kubernetes.io/configuration-snippet: |

      rewrite ^/{{ .SandboxName }}/mec_app_support(/|$)(.*)$ /mec_app_support/$2 break;

      rewrite ^/{{ .SandboxName }}/service-apis(/|$)(.*)$ /service-apis/$2 break;

      rewrite ^/{{ .SandboxName }}/published-apis(/|$)(.*)$ /published-apis/$2 break;

      rewrite ^/{{ .SandboxName }}/capif-events(/|$)(.*)$ /capif-events/$2 break;

      rewrite ^/{{ .SandboxName }}/eecs-serviceprovisioning(/|$)(.*)$ /eecs-serviceprovisioning/$2 break;

      rewrite ^/{{ .SandboxName }}/eees-eecregistration(/|$)(.*)$ /eees-eecregistration/$2 break;

      rewrite ^/{{ .SandboxName }}/eees-easdiscovery(/|$)(.*)$ /eees-easdiscovery/$2 break;

    {{- end }}

    {{- if .AuthEnabled }}

    nginx.ingress.kubernetes.io/auth-url: https://$http_host/auth/v1/authenticate?svc=meep-app-enablement&sbox={{.SandboxName}}&mep={{.MepName}}

%% Cell type:markdown id: tags:

# How to develop a MEC application using the MEC Sandbox HTTP REST API

This tutorial introduces the step by step procedure to create a basic MEC appcation following ETSI MEC standards.

This tutorial introduces the step by step procedure to create a basic MEC application following ETSI MEC standards.

It uses the ETSI MEC Sandbox simulator.

<div class="alert alert-block alert-danger">

    <b>Note:</b> These source code examples are simplified and ignore return codes and error checks to a large extent. We do this to highlight how to use the MEC Sandbox API and the different MEC satndards and reduce unrelated code.

A real-world application will of course properly check every return value and exit correctly at the first serious error.

</div>

%% Cell type:markdown id: tags:

## What is a MEC application

See [The Wiki MEC web site](https://www.etsi.org/technologies/multi-access-edge-computing)

%% Cell type:markdown id: tags:

## The basics of developing a MEC application

The developement of a MEC application follows a strict process in order to access the ETSI MEC services and provides valuable services to the customers.

Mainly, this process can be split in several steps:

1. Global initializations (constant, variables...)

2. Create a new instance of a MEC Sandbox (Note that using an existing one could be a solution too (see Annex A))

3. Activate a network scenario in order to access the ETSI MEC services

4. Create a new application identifier

5. Register our MEC application and subscribe to service termination (see MEC 011)

6. Use MEC services in order to provide valuable services to the customers

    6.1. Apply MEC services required subscriptions (e.g. MEC 013 location subscription)

7. Terminate the MEC application

    7.1. Remove MEC services subscriptions

    7.2. Deactivate the current network scenario

    7.3. Delete the instance of the MEC Sandbox

8. Release all the MEC application resources

**Note:** Several application identifier can be created to address several MEC application.

## Use the MEC Sandbox HTTP REST API models and code

The MEC sandbox provides a piece of code (the python sub) that shall be used to develop the MEC application and interact with the MEC Sandbox. This piece of code mainly contains swagger models to serialize/deserialize JSON data structures and HTTP REST API call functions.

The openApi file is availabe [here](https://labs.etsi.org/rep/mec/etsi-mec-sandbox/-/blob/STF678_Task1_2_3_4/go-apps/meep-sandbox-api/api/swagger.yaml) and the [Swagger editor](https://editor-next.swagger.io/) is used to generate the python stub.

The project architecture is describe [here](images/project_arch.jpg).

The sandbox_api folder contains the python implementation of the HTTP REST API definitions introduced by the openApi [file](https://labs.etsi.org/rep/mec/etsi-mec-sandbox/-/blob/STF678_Task1_2_3_4/go-apps/meep-sandbox-api/api/swagger.yaml).

The model folder contains the python implementation of the data type definitions introduced by the openApi [file](https://labs.etsi.org/rep/mec/etsi-mec-sandbox/-/blob/STF678_Task1_2_3_4/go-apps/meep-sandbox-api/api/swagger.yaml).

<div class="alert alert-warning" role="alert">

    <b>Note:</b> The sub-paragraph 'Putting everything together' is a specific paragraph where all the newly features introduced in the main paragraph are put together to create an executable block of code. It is possible to skip this block of code by removing the comment character (#) on first line of this block of code.

</div>

%% Cell type:markdown id: tags:

Before going to create our MEC application skeleton, the following steps shall be done:

1) Change the working directory (see the project architecture)

%% Cell type:code id: tags:

``` python

import os

os.chdir(os.path.join(os.getcwd(), '../mecapp'))

print(os.getcwd())

```

%% Cell type:markdown id: tags:

2) Apply the python imports

%% Cell type:code id: tags:

``` python

from __future__ import division # Import floating-point division (1/4=0.25) instead of Euclidian division (1/4=0)

import os

import sys

import re

import logging

import threading

import time

import json

import uuid

import pprint

import six

import swagger_client

from swagger_client.rest import ApiException

from http import HTTPStatus

from http.server import BaseHTTPRequestHandler, HTTPServer

try:

    import urllib3

except ImportError:

    raise ImportError('Swagger python client requires urllib3.')

```

%% Cell type:markdown id: tags:

3) Initialize of the global constants (cell 3)

%% Cell type:code id: tags:

``` python

MEC_SANDBOX_URL     = 'https://mec-platform2.etsi.org'                       # MEC Sandbox host/base URL

MEC_SANDBOX_API_URL = 'https://mec-platform2.etsi.org/sandbox-api/v1'        # MEC Sandbox API host/base URL

PROVIDER            = 'Jupyter2024'                                          # Login provider value - To skip authorization: 'github'

MEC_PLTF            = 'mep1'                                                 # MEC plateform name. Linked to the network scenario

LOGGER_FORMAT       = '%(asctime)s - %(name)s - %(levelname)s - %(message)s' # Logging format

STABLE_TIME_OUT     = 10                                                     # Timer to wait for MEC Sndbox reaches its stable state (K8S pods in running state)

LOGIN_TIMEOUT       = 3 #30                                                  # Timer to wait for user to authorize from GITHUB

LISTENER_IP         = '0.0.0.0'                                              # Listener IPv4 address for notification callback calls

LISTENER_PORT       = 31111                                                  # Listener IPv4 port for notification callback calls. Default: 36001

CALLBACK_URI        = 'http://mec-platform2.etsi.org:31111/sandbox/v1'

                                                                             #'https://yanngarcia.ddns.net:' + str(LISTENER_PORT) + '/jupyter/sandbox/demo6/v1/'

```

%% Cell type:markdown id: tags:

4) Setup the logger instance and the HTTP REST API (cell 4)

%% Cell type:code id: tags:

``` python

# Initialize the logger

logger = logging.getLogger(__name__)

logger.setLevel(logging.DEBUG)

logging.basicConfig(filename='/tmp/' + time.strftime('%Y%m%d-%H%M%S') + '.log')

l = logging.StreamHandler()

l.setFormatter(logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s'))

logger.addHandler(l)

# Setup the HTTP REST API configuration to be used to send request to MEC Sandbox API

configuration               = swagger_client.Configuration()

configuration.host          = MEC_SANDBOX_API_URL

configuration.verify_ssl    = True

configuration.debug         = True

configuration.logger_format = LOGGER_FORMAT

# Create an instance of ApiClient

sandbox_api = swagger_client.ApiClient(configuration, 'Content-Type', 'application/json')

# Setup the HTTP REST API configuration to be used to send request to MEC Services

configuration1               = swagger_client.Configuration()

configuration1.host          = MEC_SANDBOX_URL

configuration1.verify_ssl    = True

configuration1.debug         = True

configuration1.logger_format = LOGGER_FORMAT

# Create an instance of ApiClient

service_api = swagger_client.ApiClient(configuration1, 'Content-Type', 'application/json')

```

%% Cell type:markdown id: tags:

5) Setup the global variables (cell 5)

%% Cell type:code id: tags:

``` python

# Initialize the global variables

nw_scenarios     = []    # The list of available network scenarios

nw_scenario_idx  = -1    # The network scenario idx to activate (deactivate)

app_inst_id      = None  # The requested application instance identifier

got_notification = False # Set to true if a POST notification is received

```

%% Cell type:markdown id: tags:

## Create our first MEC application

The first step to develop a MEC application is to create the application skeleton which contains the minimum steps below:

- Login to instanciate a MEC Sandbox

- Logout to delete a existing MEC Sandbox

%% Cell type:markdown id: tags:

### First steps: the login/logout

Here is the first squeleton with the following sequence:

- Login

- Print sandbox identifier

- Logout

- Check that logout is effective

%% Cell type:markdown id: tags:

#### The login function

To log to the MEC Sandbox,

the login process is done in two step. In step 1, a user code is requested to GITHUB. In step 2, the user has to enter this user code to https://github.com/login/device and proceed to the authorization.

Please, pay attention to the log '=======================> DO AUTHORIZATION WITH CODE :' which indicates you the user code to use for the authorization.

It uses the HTTP POST request with the URL 'POST /sandbox-sandbox_api/v1/login?provide=github' (see PROVIDER constant).

%% Cell type:code id: tags:

``` python

# Login

def process_login() -> str:

    """

    Authenticate and create a new MEC Sandbox instance.

    :return: The sandbox instance identifier on success, None otherwise

    """

    global PROVIDER, logger

    logger.debug('>>> process_login')

    try:

        auth = swagger_client.AuthorizationApi(sandbox_api)

        oauth = auth.login(PROVIDER, async_req = False)

        logger.debug('process_login (step1): oauth: ' + str(oauth))

        # Wait for the MEC Sandbox is running

        logger.debug('=======================> DO AUTHORIZATION WITH CODE : ' + oauth.user_code)

        logger.debug('=======================> DO AUTHORIZATION HERE :      ' + oauth.verification_uri)

        if oauth.verification_uri == "":

            time.sleep(LOGIN_TIMEOUT) # Skip scecurity, wait for a few seconds

        else:

            time.sleep(10 * LOGIN_TIMEOUT) # Wait for Authirization from user side

        namespace = auth.get_namespace(oauth.user_code)

        logger.debug('process_login (step2): result: ' + str(namespace))

        return namespace.sandbox_name

    except ApiException as e:

        logger.error('Exception when calling AuthorizationApi->login: %s\n' % e)

    return None

    # End of function process_login

```

%% Cell type:markdown id: tags:

#### The logout function

It uses the HTTP POST request with the URL 'POST /sandbox-sandbox_api/v1/logout?sandbox_name={sandbox_name}'.

%% Cell type:code id: tags:

``` python

# Logout

def process_logout(sandbox_name: str) -> int:

    """

    Delete the specified MEC Sandbox instance.

    :param sandbox_name: The MEC Sandbox to delete

    :return: 0 on success, -1 otherwise

    """

    global logger

    logger.debug('>>> process_logout: sandbox=' + sandbox_name)

    try:

        auth = swagger_client.AuthorizationApi(sandbox_api)

        result = auth.logout(sandbox_name, async_req = False)  # noqa: E501

        return 0

    except ApiException as e:

        logger.error('Exception when calling AuthorizationApi->logout: %s\n' % e)

    return -1

    # End of function process_logout

```

%% Cell type:markdown id: tags:

Now, let put in action our Login/Logout functions:

%% Cell type:code id: tags:

``` python

#%%script echo skipping

# Uncomment the ;line above to skip execution of this cell

%%script echo skipping

# Uncomment the line above to skip execution of this cell

def process_main():

    """

    This is the skeleton of our MEC application:

        - Login

        - Print sandbox identifier

        - Logout

        - Check that logout is effective

    This skeleton will be the bas of the next sprint in order to achieve a full implementation of a MEC application

    """

    global logger

    logger.debug('Starting at ' + time.strftime('%Y%m%d-%H%M%S'))

    logger.debug('\t pwd= ' + os.getcwd())

    # Login

    sandbox = process_login()

    if sandbox is None:

        return

    # Print sandbox identifier

    logger.info('Sandbox created: ' + sandbox)

    # Wait for the MEC Sandbox is running

    time.sleep(STABLE_TIME_OUT) # Wait for k8s pods up and running

    # Logout

    process_logout(sandbox)

    # Check that logout is effective

    logger.debug('To check that logout is effective, verify on the MEC Sandbox server that the MEC Sandbox is removed (kubectl get pods -A)')

    logger.debug('Stopped at ' + time.strftime('%Y%m%d-%H%M%S'))

    # End of function process_main

if __name__ == '__main__':

    process_main()

```

%% Cell type:markdown id: tags:

### Second step: Retrieve the list of network scenarios

Let's go futhur and see how we can retrieve the list of the network scenarios available in order to activate one of them and access the MEC services exposed such as MEC 013 or MEC 030.

The sequence will be:

- Login

- Print sandbox identifier

- Print available network scenarios

- Logout

- Check that logout is effective

The login and logout functions are described in cell 3 and 4.

To retrieve the list of the network scenarios, let's create a new function called 'get_network_scenarios'. It uses the HTTP GET request with the URL '/sandbox-sandbox_api/v1/sandboxNetworkScenarios?sandbox_name={sandbox_name}'.

%% Cell type:code id: tags:

``` python

def get_network_scenarios(sandbox_name: str) -> list:

    """

    Retrieve the list of the available network scenarios.

    :param sandbox_name: The MEC Sandbox instance to use

    :return: The list of the available network scenarios on success, None otherwise

    """

    global PROVIDER, logger, sandbox_api, configuration

    logger.debug('>>> get_network_scenarios: sandbox=' + sandbox_name)

    try:

        nw = swagger_client.SandboxNetworkScenariosApi(sandbox_api)

        result = nw.sandbox_network_scenarios_get(sandbox_name, async_req = False)  # noqa: E501

        logger.debug('get_network_scenarios: result: ' + str(result))

        return result

    except ApiException as e:

        logger.error('Exception when calling SandboxNetworkScenariosApi->sandbox_network_scenarios_get: %s\n' % e)

    return None

    # End of function get_network_scenarios

```

%% Cell type:markdown id: tags:

#### Putting everything together

Here the logic is:

- Login

- Print sandbox identifier

- Print available network scenarios

- Logout

- Check that logout is effective

%% Cell type:code id: tags:

``` python

#%%script echo skipping

%%script echo skipping

# Uncomment the ;line above to skip execution of this cell

def process_main():

    """

    This is the first sprint of our skeleton of our MEC application:

        - Login

        - Print sandbox identifier

        - Print available network scenarios

        - Logout

        - Check that logout is effective

    """

    global logger, nw_scenarios

    logger.debug('Starting at ' + time.strftime('%Y%m%d-%H%M%S'))

    logger.debug('\t pwd= ' + os.getcwd())

    # Login

    sandbox = process_login()

    if sandbox is None:

        logger.error('Failed to instanciate a MEC Sandbox')

        return

    # Print sandbox identifier

    logger.info('Sandbox created: ' + sandbox)

    # Wait for the MEC Sandbox is running

    time.sleep(STABLE_TIME_OUT) # Wait for k8s pods up and running

    # Print available network scenarios

    nw_scenarios = get_network_scenarios(sandbox)

    if nw_scenarios is None:

        logger.error('Failed to retrieve the list of network scenarios')

    elif len(nw_scenarios) != 0:

        logger.info('nw_scenarios: %s', str(type(nw_scenarios[0])))

        logger.info('nw_scenarios: %s', str(nw_scenarios))

    else:

        logger.info('nw_scenarios: No scenario available')

    # Logout

    process_logout(sandbox)

    # Check that logout is effective

    logger.debug('To check that logout is effective, verify on the MEC Sandbox server that the MEC Sandbox is removed (kubectl get pods -A)')

    logger.debug('Stopped at ' + time.strftime('%Y%m%d-%H%M%S'))

    # End of function process_main

if __name__ == '__main__':

    process_main()

```

%% Cell type:markdown id: tags:

### Third step: Activate and deactivate a network scenario

Having a list of network scenarion, the next step is to actvate (and deactivate) a network scenario. This step is mandatory to create a new application instance id and access the MEC services.

In this section, we will arbitrary activate the network scenario called '4g-5g-macro-v2x', which is at the index 0 of the nw_scenarios.

%% Cell type:code id: tags:

``` python

def select_network_scenario_based_on_criteria(criterias_list: list) -> int:

    """

    Select the network scenario to activate based of the provided list of criterias.

    :param criterias_list: The list of criterias to select the correct network scenario

    :return: 0 on success, -1 otherwise

    """

    return 0 # The index of the '4g-5g-macro-v2x' network scenario - Hard coded

```

%% Cell type:markdown id: tags:

#### The activate function

The process to activate a scenario is based on an HTTP POST request with the URL '/sandboxNetworkScenarios/{sandbox_name}?network_scenario_id={network_scenario_id}'.

%% Cell type:code id: tags:

``` python

def activate_network_scenario(sandbox_name: str) -> int:

    """

    Activate the specified network scenario.

    :param sandbox_name: The MEC Sandbox instance to use

    :return: 0 on success, -1 otherwise

    """

    global logger, sandbox_api, nw_scenarios, nw_scenario_idx

    logger.debug('>>> activate_network_scenario: ' + sandbox_name)

    nw_scenario_idx = select_network_scenario_based_on_criteria([])

    if nw_scenario_idx == -1:

        logger.error('activate_network_scenario: Failed to select a network scenarion')

        return -1

    try:

        nw = swagger_client.SandboxNetworkScenariosApi(sandbox_api)

        nw.sandbox_network_scenario_post(sandbox_name, nw_scenarios[nw_scenario_idx].id, async_req = False)  # noqa: E501

        return 0

    except ApiException as e:

        logger.error('Exception when calling SandboxNetworkScenariosApi->activate_network_scenario: %s\n' % e)

    return -1

    # End of function activate_network_scenario

```

%% Cell type:markdown id: tags:

#### The deactivate function

The process to deactivate a scenario is based on an HTTP DELETE request with the URL '/sandboxNetworkScenarios/{sandbox_name}?network_scenario_id={network_scenario_id}'.

%% Cell type:code id: tags:

``` python

def deactivate_network_scenario(sandbox: str) -> int:

    """

    Deactivate the current network scenario.

    :param sandbox: The MEC Sandbox instance to use

    :return: 0 on success, -1 otherwise

    """

    global logger, sandbox_api, nw_scenarios, nw_scenario_idx

    logger.debug('>>> deactivate_network_scenario: ' + sandbox)

    try:

        nw = swagger_client.SandboxNetworkScenariosApi(sandbox_api)

        nw.sandbox_network_scenario_delete(sandbox, nw_scenarios[nw_scenario_idx].id, async_req = False)  # noqa: E501

        return 0

    except ApiException as e:

        logger.error('Exception when calling SandboxNetworkScenariosApi->deactivate_network_scenario: %s\n' % e)

    return -1

    # End of function deactivate_network_scenario

```

%% Cell type:markdown id: tags:

### Putting everything together

Now, it is time to create the second iteration of our MEC application.

The sequence is the following:

- Login

- Print sandbox identifier

- Print available network scenarios

- Activate a network scenario

- Check that the network scenario is activated and the MEC services are running

- Deactivate a network scenario

- Logout

- Check that logout is effective

%% Cell type:code id: tags:

``` python

#%%script echo skipping

%%script echo skipping

# Uncomment the ;line above to skip execution of this cell

def process_main():

    """

    This is the second sprint of our skeleton of our MEC application:

        - Login

        - Print sandbox identifier

        - Print available network scenarios

        - Activate a network scenario

        - Check that the network scenario is activated and the MEC services are running

        - Deactivate a network scenario

        - Logout

        - Check that logout is effective

    """

    global logger, nw_scenarios, nw_scenario_idx

    logger.debug('Starting at ' + time.strftime('%Y%m%d-%H%M%S'))

    logger.debug('\t pwd= ' + os.getcwd())

    # Login

    sandbox = process_login()

    if sandbox is None:

        logger.error('Failed to instanciate a MEC Sandbox')

        return

    # Print sandbox identifier

    logger.info('Sandbox created: ' + sandbox)

    # Wait for the MEC Sandbox is running

    time.sleep(STABLE_TIME_OUT) # Wait for k8s pods up and running

    # Print available network scenarios

    nw_scenarios = get_network_scenarios(sandbox)

    if nw_scenarios is None:

        logger.error('Failed to retrieve the list of network scenarios')

    elif len(nw_scenarios) != 0:

        logger.info('nw_scenarios: %s', str(type(nw_scenarios[0])))

        logger.info('nw_scenarios: %s', str(nw_scenarios))

        # Wait for the MEC Sandbox is running

        time.sleep(STABLE_TIME_OUT) # Wait for k8s pods up and running

    else:

        logger.info('nw_scenarios: No scenario available')

    # Activate a network scenario based on a list of criterias (hard coded!!!)

    if activate_network_scenario(sandbox) == -1:

        logger.error('Failed to activate network scenario')

    else:

        logger.info('Network scenario activated: ' + nw_scenarios[nw_scenario_idx].id)

        # Wait for the MEC services are running

        time.sleep(2 * STABLE_TIME_OUT) # Wait for k8s pods up and running

    # Check that the network scenario is activated and the MEC services are running

    logger.info('To check that the network scenario is activated, verify on the MEC Sandbox server that the MEC services are running (kubectl get pods -A)')

    time.sleep(30) # Sleep for 30 seconds

    # Deactivate a network scenario based on a list of criterias (hard coded!!!)

    if deactivate_network_scenario(sandbox) == -1:

        logger.error('Failed to deactivate network scenario')

    else:

        logger.info('Network scenario deactivated: ' + nw_scenarios[nw_scenario_idx].id)

        # Wait for the MEC services are terminated

        time.sleep(2 * STABLE_TIME_OUT)

    # Logout

    process_logout(sandbox)

    # Check that logout is effective

    logger.debug('To check that logout is effective, verify on the MEC Sandbox server that the MEC Sandbox is removed (kubectl get pods -A)')