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)
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"
docker build -t idebrody/go-web-api .
docker run -p 8080:8080 idebrody/go-web-api
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
Assuming you are running the service on your localhost:8080
Documentation
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
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