Functions Lab

In this lab you will also explore serverless computing using Oracle Functions. Oracle Functions uses the open-source Fn engine.

This document is meant to be an overview of the entire lab. Throughout, you may be directed to other labs, to run specific sections. It is important that when you finish each major section, you return to this document for the next section.

As you make your way through the tutorials, look out for this icon. Whenever you see it, it's time for you to perform an action.

Note:

1. Make sure you use clear-guest or clear-internet. And NOT clear-corporate.

2. If you are using virtualbox with the "fnlab.ova" image make sure you run the entire lab inside the "fnlab VM".

Section 1 - Setting up a Docker Environment

1.1) Install Docker

• Docker Options

1.2) Verify your Docker Installation

Before we get started with functions we're going to verify that Docker is installed and working. In a terminal, type the following command:

docker --version

If Docker is installed and running, you should see output something like:

Docker version 18.03.1-ce, build 9ee9f40

NOTE: Depending on how you've installed Docker you may need to prefix docker commands with sudo in which case you would have to type:

sudo docker --version

Section 2 - Open Source Fn

With Docker successfully installed it's time to move on to functions. Functions as a Service (FaaS) platforms provide a way to deploy code to the cloud without having to worry about provisioning or managing any compute infrastructure. The goal of the open source Fn project is to provide a functions platform that you can run anywhere--on your laptop or in the cloud. And Fn will also be the basis of a fully serverless FaaS platform. With Fn you can develop locally and deploy to the cloud knowing your functions are running on exactly the same underlying platform.

2.1) Installing Fn

You've got Docker installed so the principal Fn prerequisite is satisfied. So let's start by Installing Fn.

2.2) Your First Function

Now that the Fn server and CLI are installed we can dig into the creation and running of functions. In this tutorial you'll create, run locally, and deploy a Go function. If you aren't a Go programmer don't panic! All the code is provided and is pretty easy to understand. The focus of this tutorial is on becoming familiar with the basics of Fn, not Go programming.

So let's create and deploy your first function.

2.3) Introducing the Java Function Development Kit

Fn provides an FDK (Function Development Kit) for each of the core supported programming languages. But the Java FDK is the most advanced with support for Maven builds, automatic function argument type conversions, and comprehenive support for function testing with JUnit.

The Introduction to Java Functions tutorial covers all these topics and more.

2.4) Troubleshooting

If you've been following the instructions in the tutorials carefully you shouldn't have run into any unexpected failures--hopefully!! But in real life when you're writing code things go wrong--builds fail, exceptions are thrown, etc. Fortunately the Troubleshooting tutorial introduces techniques you can use to track down the source of a failure.

2.5) Containers as Functions

One of the coolest features of Fn is that while it's easy to write functions in various programming languages, you can also deploy Docker images as functions. This opens up entire world's of opportunity as you can package existing code, utilities, or use a programming language not yet supported by Fn. Try the Containers as Functions tutorial to see how easy it is.

Section 3 - Oracle Functions

Note: For this section you do NOT need the fn server on your machine. Your CLI will connect to the OracleFunctions cloud service.

Oracle Functions is a fully managed serverless FaaS platform running in Oracle Cloud. Functions uses open source Fn Project as it's underlying FaaS platform.

3.1) Setup Local Development Environment

• Setup Local Development Environment

3.2) Functions Commands Cheatsheet

• Use the Functions Commands Cheatsheet

• Also see the fn CLI docs

3.3) Your First Function

• Hello World - Node

3.4) Troubleshooting Functions

• If you haven't already, get a PaperTrail destination syslog endpoint by following steps 1-5 from Troubleshooting Fn

• Update your app's syslog-url with the PaperTrail destination

  

  fn update app ws<NNN>app --syslog-url tcp://<your-Papertrail-destination>
  

• Inspect your app and confirm the syslog-url shown matches what you provided

  

  fn inspect app ws<NNN>app
  

• Add a console.log statement in your node function

  

    // Add a console.log statement before the return statement
    console.log("Inside helloworld node function. Name=", name);
  

• Redeploy the updated function

  

  fn -v deploy --app ws<NNN>app --no-cache
  

• Invoke the function

  

  fn invoke ws<NNN>app node-fn --display-call-id
  

  echo -n '{"name":"DOAG"}' | fn invoke ws<NNN>app node-fn --display-call-id --content-type application/json
  

• View the log statement in your PaperTrail Events console

  Nov 21 22:08:34 linuxkit-000017025c24 app_id=ocid1.fnapp.oc1.phx.aaaaaaaaagyg7suol3nt3oo24ka3i4uzt7bjf: Inside helloworld node function. Name= World
  Nov 21 22:10:07 linuxkit-000017025c24 app_id=ocid1.fnapp.oc1.phx.aaaaaaaaagyg7suol3nt3oo24ka3i4uzt7bjf: Inside helloworld node function. Name= DOAG
  

3.5) Your Second Function

• Hello World - Go

3.6) Function to OCI Object Store

• Java Function to OCI Object Store