DEPLOYING GO FUNCTIONS

Julien Bisconti

SRE / Data Engineer

contact

g.dev/julien

slides: bisconti.cloud

Why deploying Go functions ?

Mental limitations

# decisions / day
# things to remember
speed of memory / reflexes

Demo

docker swarm init
git clone https://github.com/openfaas/faas
cd faas
./deploy_stack.sh
open http://127.0.0.1:8080

How does it work

OpenFaas API Gateway routes into functions
Runs inside a container
Uses a watchdog process (web server)
Process STDIN and returns to STDOUT
Collects metrics in Prometheus

templates


import (
    "fmt"
    "io/ioutil"
    "log"
    "os"
    "handler/function"
)
func main() {
    input, err := ioutil.ReadAll(os.Stdin)
    if err != nil {
        log.Fatalf("Unable to read standard input: %s", err.Error())
    }
    fmt.Println(function.Handle(input))
}

See all templates

functions


// Handle a serverless request
func Handle(req []byte) string {
  return fmt.Sprintf("Hello, Go. You said: %s", string(req))
}

face detection handler

dockerfile

# Populate example here - i.e. "cat", "sha512sum" or "node index.js"
ENV fprocess="./handler"
# Set to true to see request in function logs
ENV write_debug="false"
EXPOSE 8080
HEALTHCHECK --interval=3s CMD [ -e /tmp/.lock ] || exit 1
CMD [ "fwatchdog" ]