I will use this keep notes of stuff I keep forgetting, and some aliases I use

.zshrc

### Just some aliases that can be added to your source
### some k8s ones were copied from https://gist.github.com/tuannvm/04487aec37d2056d8a4b4c4b9d53dd16#file-k8s-bashrc

# Get resources
# kget <pod|deployment|svc> <resource-name> <option>
kget() {
  kubectl get $@
}

# Change context
# kctx <context-name>
kctx() {
  kubectl config use-context $1
}

# Change namespace
# kns <namespace-name>
kns() {
  kubectl config set-context $(kubectl config current-context) --namespace=$1
}

# Get current context
kcurrent() {
  kubectl config current-context
}

# Delete resources
# kdel <pod|deployment|svc> <resource-name> <option>
kdel() {
  kubectl delete $@
}

# Describe resources
# kdes <pod|deployment|svc> <resource-name> <option>
kdes() {
  kubectl describe $@
}

# Exec by pod label
# Pod must have a single container
kexelb() {
  kubectl exec -it $(kubectl get pod -l $1 -o jsonpath='{.items[0].metadata.name}') -- /bin/sh
}

# Get the value of a field in a secret
# kgetsecretfval <secret-name> <field-name>
kgetsecretfval() {
  kubectl get secret $1 -o yaml | grep $2 -m 1 |  awk '{print $2}' | base64 --decode
}

# Restart Deployment with 0 downtime
# Taken from: https://github.com/kubernetes/kubernetes/issues/27081#issuecomment-238078103
kresdeploy() {
  kubectl patch deployment $1 -p "{\"spec\":{\"template\":{\"metadata\":{\"annotations\":{\"date\":\"`date +'%s'`\"}}}}}"
}

bash.md

Exit Script on Error

set -e

Set Defaults for Variable

ENV=${ENV:-development}

Compare if Variable Value Are in Array

dirs=('a' 'b' 'c')
if [[ ! " ${dirs[@]} " =~ " ${1} " ]]; then
  # do something
fi

Verify if Environment Variable is Defined

if [[ ! -z "$MYENV" ]]; then
  # $MYENV defined
fi

Replace All Environemnt Variables Inside File (Templating Using Bash)

function envsubst_config_file {
  if [[ ! -f "$1" ]]; then
    echo "File $1 not found"
    exit 1
  fi

  filename=$(basename -- "$1")
  filedir=$(dirname -- "$1")

  echo "Replacing envs in file $filename in dir $filedir"
  cat $1 | envsubst > $filedir/out/$filename
}