K8s try out repo 2020

How to run locally

1. cd api && go run main.go
2. cd customersvc && go run main.go
3. cd greetsvc && go run main.go

How to run 1 docker container locally

1. docker run -t -d <image>

How to run locally with docker-compose

1. docker-compose up
   Check with:

• docker exec -it <container> /bin/bash

How to start a k3s cluster

1. wget -q -O - https://raw.githubusercontent.com/rancher/k3d/master/install.sh | TAG=v1.7.0 bash to install k3d
2. k3d create --api-port 6550 --publish 8090:80 --workers 3 # 80 is the ingress port that traefik listens on
3. export KUBECONFIG="$(k3d get-kubeconfig --name='k3s-default')"
4. kubectl cluster-info
5. kubectl get all -o wide
6. For login credentials, see cat $KUBECONFIG

How to deploy to k3s

1. Make sure latest images have been built: docker-compose build
2. And have been tagged: docker tag k8s-tryout-2020_api:latest ggerritsen1/k8s-tryout-2020_api:latest
3. And have been pushed: docker push ggerritsen1/k8s-tryout-2020_api:latest

Then:

1. kubectl apply -f api-deployment.yaml
   Check with:

• kubectl get pods -o wide
• kubectl logs -f -lapp=k8s-tryout-2020-frontend --all-containers=true --max-log-requests=10
• kubectl logs -f -lapp=k8s-tryout-2020-backend --all-containers=true

1. Open http://api.localhost:8090/hello to see that it works

Troubleshoot

1. Run bash on a specific container kubectl exec -it pod/k8s-tryout-2020-api-deployment-54d587f5bf-qqpwv -- /bin/bash
2. Run bash on a helper container kubectl --namespace=default run -it --image=alpine helper-container, then wget -SO- k8s-tryout-2020-api/hello
3. See traefik dashboard:

• kubectl -n kube-system edit configmap traefik, then add:

  [api]
      dashboard = true 

• kubectl -n kube-system port-forward deployment/traefik 8080 and open http://localhost:8080

Next steps

• Make smaller containers (from scratch)
• Try https://k8slens.dev/
• Add a database
• Add integration with an external endpoint/system

Sources

• Docker compose docs
• https://levelup.gitconnected.com/complete-guide-to-create-docker-container-for-your-golang-application-80f3fb59a15e
• https://nickjanetakis.com/blog/docker-tip-10-project-structure-with-multiple-dockerfiles-and-docker-compose
• https://medium.com/burak-tasci/full-stack-monorepo-part-i-go-services-967bb3527bb8
• https://itnext.io/run-kubernetes-on-your-machine-7ee463af21a2
• https://multipass.run/
• https://katacoda.com/courses/kubernetes/playground
• https://github.com/rancher/k3d
• https://medium.com/@zhimin.wen/running-k3s-with-multipass-on-mac-fbd559966f7c
• https://sysadmins.co.za/develop-build-and-deploy-a-golang-app-to-k3s/
• https://medium.com/google-cloud/kubernetes-101-pods-nodes-containers-and-clusters-c1509e409e16
• https://medium.com/google-cloud/kubernetes-110-your-first-deployment-bf123c1d3f8
• https://medium.com/@geraldcroes/kubernetes-traefik-101-when-simplicity-matters-957eeede2cf8
• k3d-io/k3d#103
• k3s-io/k3s#350
• https://rancher.com/docs/k3s/latest/en/installation/kube-dashboard/