fn-serverless/examples/tutorial/hello/go/README.md

Tutorial 1: Go Function w/ Input (3 minutes)

This example will show you how to test and deploy Go (Golang) code to Oracle Functions. It will also demonstrate passing data in through stdin.

First, run the following commands:

# Initialize your function creating a func.yaml file
fn init <DOCKERHUB_USERNAME>/hello

# Test your function. This will run inside a container exactly how it will on the server
fn run

# Now try with an input
cat hello.payload.json | fn run

# Deploy your functions to the Oracle Functions server (default localhost:8080)
# This will create a route to your function as well
fn deploy myapp

Now call your function:

curl http://localhost:8080/r/myapp/hello

Or call from a browser: http://localhost:8080/r/myapp/hello

And now with the JSON input:

curl -H "Content-Type: application/json" -X POST -d @hello.payload.json http://localhost:8080/r/myapp/hello

That's it!

Note on Dependencies

In Go, simply put them all in the vendor/ directory.

In Review

1. We piped JSON data into the function at the command line

   cat hello.payload.json | fn run
   

2. We received our function input through stdin

   json.NewDecoder(os.Stdin).Decode(p)
   

3. We wrote our output to stdout

   fmt.Printf("Hello")
   

4. We sent stderr to the server logs

   log.Println("here")
   

Next Up

Tutorial 2: Input Parameters