Introduction

This repo contains all the concepts useful to brush up your knowledge in enterprise software development and DevOps.

Links

https://kubernetes.io/docs/concepts/overview/components/ official docs, very useful overview

Commands

MISC

az acr build --resource-group <rg> --registry <acr> --image <image>:<tag> . upload image to registry

HELM

helm repo add bitnami https://charts.bitnami.com/bitnami add a helm repo
helm search repo bitnami list available images

Kubernetes

kubectl create secret to keep and spread secrets
kubectl get endpoints ratings-api --namespace ratingsapp see what you are exposing
kubectl config delete-context <context_name> clean kubeconfig context
kubectl config set-context <ctx_name> --namespace=<ns> create a new context
kubectl config use-context <ctx_name> use context as default
kubectl port-forward [<pod-name> or services/<service-name>] 8080:80 forward local traffic, to pod or load balancer
kubectl cp <pod-name>:<filepath> <filepath> copy file to local machine
kubectl cp $HOME/<filepath> <pod-name>:<filepath> copy file from remote machine
$ kubectl get deployments kuard --export -o yaml > kuard-deployment.yaml $ kubectl replace -f kuard-deployment.yaml --save-config export a deployment into a file and then store changes
kubectl run -i oneshot run a single job once
kubectl proxy similar to port forward, but instead of sending TCP traffic you send HTTP requests, port forward is for internal access and debugging, proxy is to forward traffic
kubectl top nodes top
kubectl expose deployment <my-deplo> To create a service
k get deploy kuard-deployment -o jsonpath --template {.spec.selector.matchLabels} Which labels is my deployment matching?
kubectl replace -f <filename> --save-config Replace the deployment in the file and save the modified config in its annotation
kubectl rollout status deployments <deployment-name> Check the rollout status
kubectl label <resource> ____
k create configmap test-config --from-file=test-config.txt --from-literal=extra-param=extra-value --from-literal=another-param=another-value Create ConfigMap
k create secret generic <name> --from-file=<filename> ____
kubectl replace -f - Read file from stdin and use it to replace a resource (fx. create with --dry-run -o yaml and then use this to update a secret from files on disk without having to manually base64-encode data)
kubectl auth can-i get pods --subresource=logs Can if I'm auth to do a verb
kubectl auth reconcile Reapply RBAC changes
kubectl run -it --rm --image busybox busybox ping <svc dns name> Run pod interactively and ping

Examples: KUARD_LB=$(kubectl get service kuard -o jsonpath='{.status.loadBalancer.ingress[*].hostname}') query a specific deployment for a parameter

Terraform

terraform init --backend-config="<key>=<value>" ____
terraform apply -var="<key>=<value>" pass sensitive variqables from command line
terraform show look the current state of the infrastructure
TF_VAR_<variable> this environment-variable can be set to set the terraform variable.
terraform state list list all resources provisioned via terraform
terraform plan -out=newplan write the plan into file, you can follow this with <terraform apply "newplan"
terraform validate spellcheck tf files
`` ____

Docker

docker run -d --name kuard --publish 8080:8080 gcr.io/kuar-demo/kuard-amd64:blue ____
docker stop kuard ____
docker system prune delete all untagged images, all stopped containers etc

riccardodl/knowledge_base