Programming test Simon Spiridonov

run the docker-compose

mkdir -p data/grafana ; chmod 777 data/grafana; docker-compose up -d --build

After launch it will:

Download images and build the application
Run influxdb and grafana
Application will run automatically after influxdb is started and healthy
Application will gather history and store it to influxdb using ./main history --from 2018-01-01 --to 2019-01-01 as run command
CronD in app container will run ./main update every 6 hours and application will try to push new data from https://api.exchangeratesapi.io/latest ot InfluxDB
You can open http://localhost:3000 in your browser to access grafana
Use admin/admin credentions
Navigate to "Manage" and then to "Currency" dashboard
You will see USD currency exchange rate
You can change currency in upper left corner
To add more data to influxdb run commands:
- docker exec -i app ./main update
- refresh grafana page to see the difference
- docker exec -i app ./main history --from 2019-01-01 --to 2019-04-01
- refresh grafana page to see the difference

Tools

InfluxDB

It can efficiently store values relative to timestamps

Golang

I'm writing on this language for ~2 months and I enjoy learning it. So I decided to do this task to learn more. I prefer this language to python for workng with data.

Grafana

It's so easy to display data from InfluxDB using grafana :)

Kubernetes

docker build -f Dockerfile_grafana -t docker-registry.ppdev.ru/app/grafana:latest .
docker push docker-registry.ppdev.ru/app/grafana:latest
docker tag exchangehistory_app docker-registry.ppdev.ru/app/app:1
docker push docker-registry.ppdev.ru/app/app:1
helm upgrade ./helm --install --kube-context stage --namespace app --set-file config_ini=config/config.ini --set build_id=1

After this application wil be deployed and filled with same history as on local deployment with docker-compose. You can add to /etc/hosts:

<your ingress ip> grafana.app.check24dev.de

And you will be able to use grafana.

To test cronjob run this:

kubectl --context stage --namespace app create job app-upd --from=cronjobs/app