TC2.25 - Creating a MicroService for IOT App by Exploiting RestCall APIs services

1. For this example we use the Rest Call https://servicemap.disit.org/WebAppGrafo/api/v1/feedback/last/, a Smart City API to request the last feedback sent by the users to service map.
2. The Rest Call needs as parameters the format of the response and the language of the user.
3. To create the microservice,  make the login on the snap4city portal
   
4. Click on the ‘Resource Manager: Process Loader > MicroServices fot IOT Applications’ menu to view all own resources and the related metadata
5. Click on the Button (‘Add Microservice') button

Fig: Upload button.

1. A pop up will open: fill the fields and press the ‘Confirm’ button. For example, if you want to create a Microservice:
   • App Type: Microservice
   • Description: Retrieve last feedback sent by the user
   • Nature: Services
   • Sub-Nature: Feedback
   • Micro Service Title: last-feeback
   • Help: Retrieve last feedback sent by the user
   • url: https://servicemap.disit.org/WebAppGrafo/api/v1/feedback/last/
   • parameter1: format
   • parameter2: lang
   • Method: GET
   • Authentication: No
     
1. When the confirm button is clicked the Microservices is created and a Final User can publish it and then import it directly into an IoT App:
   
2. For the publication of the microservice it is necessary that the license given is public and this can be done by writing Public in the field of the license.
3. 
4. You can then press the button that says NO in the Published column. A confirmation will be requested and the user will have to press the Confirm button.
5. 
6. Once the user has published the service, he can import it autonomously into his own Iot Application, through the Import External Microservices menu.
7. 
8. Click on the name of your microservice and next to install
9. 
10. After the correct installation message has been shown at the top of the page, you can search for the node in the left side menu to use it.
    
11. And in this example we create a simple flow to show the functionalities offers by this microservice. Inserting these configurations:
    
12. And create this simple flow:
    
13. Pressing on the button of the node labelled as timestamp, in the debug tab it is possible to see the result of the Rest Call:

1. Follow the previous example until the point 5.
2. A pop up will open: fill the fields and press the ‘Confirm’ button. For example, if you want to create a Microservice:
   
   1. App Type: Microservice
   2. Description: Retrieve last tweet and retweet related to a channel
   3. Nature: Services
   4. Sub-Nature: Social Media
   5. Micro Service Title: twitter-last-channel
   6. Help: Retrieve last tweet and retweet related to a channel
   7. url: https://www.disit.org/rttv/query/select.php
   8. parameter: TwRtwChannel
   9. Method: GET
   10. Authentication: Yes

1. When the confirm button is clicked the Microservices is created and a Final User can publish it and then import it directly into an IoT App:
   
2. For the publication of the microservice it is necessary that the license given is public and this can be done by writing Public in the field of the license.
3. 
4. You can then press the button that says NO in the Published column. A confirmation will be requested and the user will have to press the Confirm button.
5. 
6. Once the user has published the service, he can import it autonomously into his own Iot Application, through the Import External Microservices menu.
7. 
8. Click on the name of your microservice and next to install
9. 
10. After the correct installation message has been shown at the top of the page, you can search for the node in the left side menu to use it.
11. 
12. Differently to the previous node in this case in the configuration tab must be inserted also the username and the password to allow the access to the rest call
    
13. Creating a simple flow like the previous:
    
14. Pressing on the button of the node labelled as timestamp, in the debug tab it is possible to see the result of the Rest Call: