golang-web

README

HTTP web server with Prometheus metrics in Go

• http web server running by default on port 8080 that is intended for testing.
• Prometheus formatted metrics available at "/metrics" with key "total_request_count" using prometheus/client_golang library.
• Kubernetes compatible health check available at "/healthz".

Running image locally

In terminal #1

cd golang-web
make make image-test-fg

In terminal #2

xdg-open http://localhost:8080/myhello/

Pulling image from GitHub Container Registry

docker pull ghcr.io/andriykalashnykov/golang-web:latest

Environment variables available to image

• PORT - listen port, defaults to 8080
• APP_CONTEXT - base context path of app, defaults to '/'

Environment variables populated from Downward API

• MY_NODE_NAME - name of k8s node
• MY_POD_NAME - name of k8s pod
• MY_POD_NAMESPACE - namespace of k8s pod
• MY_POD_IP - k8s pod IP
• MY_POD_SERVICE_ACCOUNT - service account of k8s pod

Tagging

newtag=v0.0.1
git commit -a -m "changes for new tag $newtag" && git push
git tag $newtag && git push origin $newtag

Deleting a tag

# delete local tag, then remote
todel=v0.0.1
git tag -d $todel && git push origin :refs/tags/$todel

References

• https://ashishb.net/tech/docker-101-a-basic-web-server-displaying-hello-world/
• https://tutorialedge.net/golang/creating-simple-web-server-with-golang/
• https://blog.gopheracademy.com/advent-2017/kubernetes-ready-service/
• https://semaphoreci.com/community/tutorials/how-to-deploy-a-go-web-application-with-docker
• https://prometheus.io/docs/tutorials/instrumenting_http_server_in_go/