functions

Introduction

In this guide, we'll show you a few simple steps to launch an Oracle Linux instance on Oracle Cloud Infrastructure, and then proceed to launch your Fn Project Functions server & run your cloud functions. The path that we will take is as follows:

• Launch your Oracle Linux instance in the Oracle cloud
• Install Oracle Container Runtime for Docker
• Install the Fn Functions Server
• Configure and run your Oracle Code Card Fn functions
• Create a Fn function for your Code Card

Create an Oracle Linux instance on the Oracle Cloud Infrastructure

Follow these instructions to create an Oracle Linux instance and the come back after you are done.

Configuring your Fn Server

Your Oracle Linux instance is now running, and ready to be configured to host your cloud functions.

Install and configure Docker

While connected to your Oracle Linux instance, run the following commands to install and configure the Docker container runtime.

sudo yum -y install docker-engine-18.03.1.ol-0.0.9.el7.x86_64 -y
sudo usermod -aG docker opc
sudo systemctl enable docker
sudo systemctl start docker

Before proceeding further, logout of the current SSH session, & then reconnect to your Oracle Linux instance and log back in vis SSH. This is to ensure group membership configured in the previous step is correctly applied and in effect. Once you have reconnected to the instance, run the following command to install the Fn CLI tool (this will download a shell script and execute it).

Configure Oracle Linux for Fn

curl -LSs https://raw.githubusercontent.com/fnproject/cli/master/install | sh

At completion, the installation will output the Fn CLI version - per the below example output.

fn version 0.5.16

        ______
       / ____/___
      / /_  / __ \
     / __/ / / / /
    /_/   /_/ /_/`

SELinux constraints

Before you can start Fn you must relax SELinux constraints by running this command:

sudo setenforce permissive

Start your Fn Server

Run the following command which will start Fn in the background as a single server mode, using an embedded database and message queue.

fn start -d

Your Fn server is now instantiated and running in the background.

Configure and run your Fn functions

Functions are small but powerful blocks of code that generally do one simple thing. Forget about monoliths when using functions, just focus on the task that you want the function to perform. Our CLI tool will help you get started super quickly.

To create a hello world function, run the following command.

fn init --runtime go --trigger http hello

This will create a simple function in the directory hello, so let's cd into it:

cd hello

Deploy your functions to your local Fn server

fn deploy --app codecard --create-app --local

Now you can call your function locally using curl:

curl http://localhost:8080/t/codecard/hello

or, using the Fn client:

fn invoke codecard hello

or in a browser: http://:8080/t/codecard/hello-trigger

That's it! You just deployed your first function and called it. You are now ready to configure your Code Card to access your cloud function!

Create a Fn function for your Code Card

The Code Card needs to receive the following JSON format:

Required fields:

{
	"template": "template[1-11]",
	"title": "Hello World",
	"subtitle": "This is a subtitle",
	"bodtext": "This is the body",
	"icon": "[see list of named icons| BMP url]",
	"backgroundColor": "[white|black]"
}

**Check out the list of available named icons here*.

Optional fields:

{	...
	"badge": [0-100] It will override the icon
	"backgroundImage": "[oracle|codeone | BMP url]" Only for templates that have backgrounds
	"fingerprint": "" The SHA-1 signature of the server containing the custom icon or backgroundImage URL.
	...
}

To checkout all available templates go to Oracle Events App -> Code One --> Code Card Designer.

Let's create our first Code Card function!

fn init --runtime node --trigger http button1
cd button1
```bash

Now lets edit the func.js file using `nano` or `vi`.

```bash
nano func.js
```bash

Modify the handle function to look like this:

```bash 
fdk.handle(function(input){
    let codeCardJson = {
      template: 'template1',
      title: 'Hello there!',
      subtitle: 'How are you?',
      bodytext: 'This is my first Fn function from the Oracle Cloud.',
      icon: 'opensource',
      backgroundColor: 'white'
    }
    return codeCardJson
})

In nano Ctrl + O and Ctrl + X (WriteOut and Exit.)

In vi ESC :wq (write and quit.)

Now deploy your new function

fn deploy --app codecard --local

And test on your browser

http://<linux-instance-public-ip>:8080/t/codecard/button1

Now you are ready to configure your Code Card to point to your new function!

Configure Code Card

In this example, we will program the shortpress action for button B on the card.

Establish serial connection with Code Card

In order to configure our Code Card, we need to establish a serial connection over USB to the CodeCard CLI. Follow this guide to establish the serial over USB connection. Remember to ensure that the Code Card WiFi settings are configured correctly also! (Direction available from the referenced guide).

Configure buttonb1 button action

In the Code Card CLI, buttonb1 correlates to button B shortpress action.

In your terminal session you should now see the Code Card CLI Menu, as follows.

***************************************************************************************
  Code Card v1.0
  Oracle Groundbreakers
  developer.oracle.com/codecard
***************************************************************************************
Commands:
  ls                Show all stored key/values
  help              Show this help
  shortpress[a|b]   Simulate the press of a button
  longpress[a|b]    Simulate the long press of a button
  connect           Connect to wifi
  disconnect        Disconnect wifi
  restart           Restart wifi
  status            Show wifi status
  home              Show home screen
  reset             Reset to factory settings

Usage:
  Read saved key value:
    key
  Save new key value:
    key=[value]

Available keys:
  ssid, password, buttona1, buttona2, buttonb1, buttonb2, fingerprinta1, fingerprinta2,
  fingerprintb1, fingerprintb2, methoda1, methoda2, methodb1, methodb2,
>>>

First, we will set the HTTP method for the B shortpress by entering the following command. Keep in mind that pausing for 2 seconds while typing will automatically enter the command. It may be easier to pre-type the commands elsewhere and copy-paste them into the window.

methodb1=GET

Code Card will confirm setting update as follows.

>>>
Value saved for methodb1: GET
>>>

Next configure the HTTP endpoint for the B shortpress by entering the following command. Be sure to substitute values in <brackets> as appropriate.

buttonb1=http://<linux-instance-public-ip>:8080/t/codecard/button1

Code Card will confirm setting update as follows.

>>>
Value saved for buttonb1: http://<linux-instance-public-ip>:8080/t/codecard/button1
>>>

Invoke the function from the Code Card

Ok, so now our cloud function and Code Card are ready to Go! Powercycle your Code Card and perform a button B shortpress. If your card is still connected via the serial connection, you will see output similar to the following.

Button b - short pressed
>>>
Connecting to 'pmac851' ...................connected!
IP address: 192.168.43.13
MAC address: 84:0D:8E:A7:89:5B
>>>
Request:
  host: 129.213.19.161
  port: 32690
  url: http://`linux-instance-public-ip`:8080/t/codecard/button1
  method: GET
text/plain;charset=UTF-8
Response:
  {"template":"template1","title":"Hello there!","subtitle":"How are you?","bodytext":"This is my first Fn function from the Oracle Cloud.","icon":"opensource","backgroundColor":"white"}
>>>