The bartender as a function

Objectives

The main objective of this Workshop is to make you to code in go language by creating a serverless application. You are going also to explore a microservice architecture over aws using lambdas.

It is presented as a simple game: You are the waiter of a bar. You should wait for the clients' commands and generate the bill.

Don't worry, I have coded for you the client and the bartender. ☺️ .

I give you also the structure of the waiter project. It includes the aws-sam templates and the unit tests of the services (functions) you should code.

Before you start: Requirements

• aws cli
• go > 1.10
• go dep
• sam local
• docker
• a profile "xebia" for aws-cli with your aws credentials

Creating a profile for aws cli

Go to your security credentials in your aws console, and create an access key. Copy your aws_access_key_id and your aws_secret_access_key and create your ~/.aws/credentials and ~/.aws/config files as stated in this instructions: https://docs.aws.amazon.com/cli/latest/userguide/cli-multiple-profiles.html Your profile should be called xebia (or modify the provided scripts to use the name of the profile you want to use).

The exercise

Create your GOPATH environment variable with the path to your go projects. Inside this path, create a folder src.

$ cd $GOPATH/src

$ git clone https://github.com/dicaormu/bartenderAsFunction

During this exercise, if you have any question, you can go to the faq. You can also take a look to the "solution" branch with a suggested solution.

Step 1

The client is an IOT device who asks for a list of food and/or beer. As waiter you have to:

• listen to those messages (see the sam.yml file, LambdaRuleReadCommand)
• generate and id for the command
• save the command to a Dynamodb table

Again, don't worry, you have to execute all tests in file readCommand_test.go , once they "pass", you can be sure your function works There are also "todo" comments in the readCommand.go file.

Step 2

The bartender ask you for the unattended commands, it means, you should expose a rest api to allow the bartender to ask you for those commands. As waiter you should:

• listen to the rest calls of the bartender (see the sam.yml file, LambdaGetCommands)
• read from the database all commands you have not served
• return them to the bartender

This time, if you execute all tests in getCommand_test.go file, and make them pass, everything should be ok.

Step 3

The bartender gives you a command to serve, it means, you should expose a rest api to allow the bartender to ask you to serve those commands. As waiter you should:

• Know the command the bartender ask you to "attend" (see the sam.yml file, LambdaServeCommands). The bartender gives you the "id" of the command and the item he wants you to serve
• read the command from the database
• change the status of the item to "served"

Tests are implemented in serveCommand_test.go.

Step 4

The bartender ask you for the served commands, it means, you should expose a rest api to allow the bartender to ask you for those commands. As waiter you should:

• listen to the rest calls of the bartender (see the sam.yml file, LambdaGetFacture)
• read from the database all commands you have served
• return them to the bartender

Tests are implemented in getFacture_test.go.

Deploy your solution and enjoy!!!

Register your api:

Make a post to the URL i'll give you in the workshop with the body:

{ 
"name":"USERXX",
"url":"URL_OF_YOUR_DEPLOYEDAPI"
}