I’ve come across several cases lately where I need to implement some kind of filtering on a slice of records based on business logic requirements. At a first pass, the simplest solution may be to do filtering in-line, looping through your set of records and discarding whatever records don’t match your business requirements. However, this can quickly become unmanageable when you need to apply completely different filters in some situations. Code gets duplicated all over the place, filters get messy, the flow of the program becomes difficult to follow, testing code becomes exponentially more difficult, and the next engineer on…

Spotify exposes a robust API that can be used to manage your (or someone elses) music library and do all sorts of fun things with it. Once OAuth 2 authentication is set up and ready to go, an application can continually interact with the Spotify API on behalf of a user to do anything from getting basic information about a user to seeking to a position in a currently playing song.

In this post, we’re going to walk through setting up a Go application hosted on AWS Lambda that does some simple library management involving the Discover Weekly playlist. Specifically…

This is a quick discussion of how to set up a local development environment for a Go API running inside of a Docker container with hot reloading. I’ve found this to be an effective way to develop locally. The full source code can be found on GitHub.

API

We’ll first set up a dummy API in cmd/api/main.go:

package main import (
    "fmt"
    "log"
    "net/http"
) func handler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprint(w, "Hello from the api!") 
}func main() {
    http.HandleFunc("/", handler)
    log.Println("listening on 5000")
    log.Fatal(http.ListenAndServe(":5000", nil))
}

This API simply listens on the root path and returns a hello world…

Sun Jul 15, 2018

This post assumes a base level of knowledge in AWS Lambda functions written in Go. The Official Documentation is a great place to start if you are unfamiliar with the basics of Lambda functions written in Go.

Introduction

With the addition of native Go support for AWS Lambda, writing Lambda functions in Go has become much simpler since using a shim is no longer needed. The AWS Lambda Go library provides a framework for writing Lambda functions and working with a variety of event sources. The lambda.Start(handler) pattern lets you write a function that takes in an…