1. Command Microservice Deep Dive
Tech Talks – Session 6

2. Agenda Command's general purpose and background
Why a separate micro service for commands
Command’s makeup – including technologies/libraries/tools used
REST API outline (categorizing the APIs by purpose)
Command relationship to Device Profile
With Demo!!
Configuration settings
Brief project status/update (what’s going on)
Q&A

3. Jim White Dell Distinguished Engineer & Senior Software Architect
From Dell End User Computing (EUC) CTO
Chief Architect and lead developer of Fuse
I wrote code line #1 
Fuse => EdgeX Foundry

4. Big Picture and Command

5. Command’s Role Also known as the Command and Control micro service
Enables the issuance of commands or actions to devices and sensors on behalf of:
other microservices within EdgeX Foundry (for example, a local edge analytics or rules engine microservice)
other applications that may exist on the same system with EdgeX Foundry (for example, a system management agent that needs to shutoff a sensor)
To any external system that needs to command those devices (for example, a cloud-based application that had determined the need to modify the settings on a collection of devices)
Exposes the commands in a common, normalized way to simplify communications with the devices.
Commands to devices are made through the command GET, a request for data from the device or sensor,
and the command PUT, a request to take action or receive new settings or data from EdgeX Foundry.
Command does not act alone
It gets its knowledge about the devices and sensors from the Metadata service
It relays commands and actions to the devices and sensors through the Device Service
It never communicates directly to a device or sensor.

6. Why have a Command Microservice
Couldn’t other microservices or applications talk directly to device services?
Yes, but…
Command can provide a layer of protection around devices and sensors
It provides security services a means to not allow unwarranted interaction with the devices and sensors through the Device Service
It could aggregate and organize requests to multiple device/sensors
Allowing for synchronization and/or ordering of requests (shutoff the electricity, and then open the access panel)
It could filter command requests
All features envisioned for future releases

7. Command Makeup Created with Java/Spring Framework/Spring Boot
Uses Spring MVC for REST communications
Command has no database – it gets all its information from other microservices
Dell is creating a Go Lang Command Data replacement

8. Command Retrieve available commands

9. Command Put (but same for Get)

10. Command REST APIs Get all devices (and commands) Get Commands by
/api/v1/device/name/{name}
Get Commands by
Device id
/api/v1/device/{id}
Device name
/api/v1//device/name/{name}
Issue command
/api/v1/device/{id}/command/{command id}
GET & PUT (depending on data request or actuation)

11. Command REST APIs (continued)
Set the admin state
/api/v1/device/{id}/adminstate/{adminState}
Can also be done by device name
Set the op state
/api/v1/device/{id}/opstate/{opState}
Ping the service
/api/v1/ping

12. Demo
It can sometimes be difficult to see how actuation commands are reflected through the profile and then the various microservices
Metadata
Device Service
Command
Let’s see a demo (using virtual device service)
See the original Device Profile (and its commands)
See how Meta data’s provides those commands through its APIs
See how the commands are exposed through the device service
See how Command offers the same commands through its APIs

13. Command Config Options
Nothing extra-ordinary in Command
Other standard config options
Service port
Location of associated micro services
Log levels
Read limits

14. Project Status and Significant Updates
60 companies now enrolled in EdgeX
Barcelona Release (the first community release)
Due Oct 3rd
Shown at IoT Solutions World Congress in Barcelona
See Wiki for feature list
Next tech community meeting held simultaneously there (Oct 5th)
Working Groups all working toward Barcelona MVP
Processes and documentation filling
Build and test facilities filling in

15. Upcoming Tech Talks Are these talks still useful
Are there suggestions you can make on how to improve
Consul and Config/Registry micro service
Export micro services
Using the SDK to generate a device service
me other suggestions

16. Questions and Answer Time