learning-webapi-go

README

learning-webapi-go

Learning how to write a webapi in golang

Using this exercise to learn about golang and how to write a web api in it.

Based on https://dev.to/moficodes/build-your-first-rest-api-with-go-2gcj

It is a very simple API, exposes add, substract, division and random at /api/v1 It also contains:

• /metrics endpoint for prometheus,
• /liveness and /readiness for kubernetes healthchecks
• /docs/ endpoint for documentation using Swagger (swaggo/swag)

Unit testing

go test -v 

or with a docker image

docker run --rm -v ${PWD}:/testme  golang:1.17-buster bash -c "cd /testme && go test -v"

Building

docker build -t idebrody/go-web-api .

Running with Docker

docker run -p 8080:8080 idebrody/go-web-api

Running it in Kubernetes

There is a combined manifest at kubernetes/go-web-api-nginx.yaml

• Deployment with healthchecks
• Service
• HorizontalPodAutoscaler
• Ingress, nginx ingressClassName, the route is set to go-web-api.dev.engineering.somecompany.cloud, which you might need to change according to your hosted domain

Tested on Kubernetes version 1.21.3

Using your default namespace

kubectl apply -f kubernetes/go-web-api-nginx.yaml

Using idebrody as a namespace

kubectl apply -f kubernetes/namespace.yaml
kubectl apply -n idebrody -f kubernetes/go-web-api-nginx.yaml

Availabe Endpoints and Examples

Assuming you are running the service on your localhost:8080

Documentation

http://localhost:8080/docs/

ADD

Add together 2 numbers

http://localhost:8080/api/v1/add?num1=13&num2=3.1415926

Division

Divide 2 numbers

http://localhost:8080/api/v1/division?num1=9.27&num2=3

Random

Generate 23 random numbers, default is 10

http://localhost:8080/api/v1/random?Count=23

Substract

Substract 2 numbers

http://localhost:8080/api/v1/substract?num1=9&num2=1.414

Metrics

Prometheus metrics

http://localhost:8080/metrics

Liveliness

It has no output it only returns StatusOK or StatusInternalServerError

http://localhost:8080/liveness

Readiness

It has no output it only returns StatusOK or StatusInternalServerError

http://localhost:8080/readiness