KUBECONFIG helper scripts - magic

.0README.md

Install

Add this to you ~/.bashrc

if [ -f ~/.kube/.kube-config.sh ]; then 
  source ~/.kube/.kube-config.sh
else 
  curl -sLo ~/.kube/.kube-config.sh https://gist.githubusercontent.com/lalyos/f851fd3273fead83146eeca6822a9604/raw/.kube-config.sh
  source ~/.kube/.kube-config.sh
fi

Functions

• kk: prints the actual KUBECONFIG
• kselect: select one from files matching $KCPATTERN. All shells sharing this. Be careful: ctx change in one shell has effect to all other shells.
• kc: sets default KUBECONFIG. combines all matching file: KUBECONFIG=file1:file2:file3
• kct: new multifile KUBECONFIG, with a temp dumy config in the first place. Usage: the shell get an independent KUBECONFIG, ctx changes don't effect other shells.
• ksub: creates a subshell with a new KUBECONFIG. The first entry is a temporal dummy kubeconfig.

Configuration

You can use the following env variables

KCPATTERN Your KUBECONFIG naming conventions. Examples:

• *.yaml: all yaml files [default]
• config*: all files starting with config

tl;dr

If you have a single file in KUBECONFIG than the actual ctx is stored in the current-context field. But if you have a lot of config files in ~/.kube:

• ~/.kube/prod (has 1 contex:prod)
• ~/.kube/dev (has 1 contex:dev)
• ~/.kube/qa (has 1 contex:qa)

Than imagine you set KUBECONFIG=~/.kube/prod:~/.kube/dev:~/.kube/qa Now you switch betwen contextes easily (k ctx), without changing the KUBECONFIG env var. But let say you switch to qa context: now because the first entry in KUBECONFIG is ~/.kube/prod the current-context field will be set to dev in that file.

Next time you want to use it alone KUBECONFIG=~/.kube/prod it will error out because it references to a nonexisting context.

So the workaround: whenever you use KUBECONFIG=fil1:file2:file3 always insert a dummy file, as the first entry. You can easily create a dummy file:

(KUBECONFIG=~/.kube/dummy kubectl config view)> ~/.kube/dummy

So if you want to have multiple file in KUBECONFIG, the first entry should be a dummy: KUBECONFIG=dummy:fil1:file2:file3

.kube-config.sh

######################################
## KUBECONFIG helpers
######################################

# aliases
alias k='kubectl'
alias kal='kubectl get all'
alias kg='kubectl get'
alias kgs='kubectl get -n kube-system'
alias kgy='kubectl get -o yaml'
alias kke='code ${KUBECONFIG:-$HOME/.kube/config}'
alias kp='[[ "$K8S_PROMPT" ]] && unset K8S_PROMPT || K8S_PROMPT=1'

# prints actual KUBECONFIG
kk() {
  echo KUBECONFIG=$KUBECONFIG
}

kunset() {
  unset KUBECONFIG
}

kd() {
    kubectl "$@" --dry-run -o yaml
}

rspec() {
    kubectl get rs ${1:? required} -o yaml | kubectl neat | yq .spec -y | grep -v 'pod-template-hash:\|replicas:'
}


# selects a single yaml from ~/.kube as KUBECONFIG 
kselect-old() {
    select conf in ~/.kube/${KCPATTERN:-*.yaml}; do
        echo selected: ${conf};
        break;
    done;
    export KUBECONFIG=${conf}
}

kctx() {
  k config get-contexts
}

kselect() {
  find ~/.kube/${KCPATTERN:-config*} \
  | fzf -m \
      --cycle \
      --prompt='KUBECONFIG >' \
      --header 'press TAB to select multiple (deselect: shift-TAB) / ENTER to finish' \
  | tee .kc
  if [[ $(cat .kc | wc -l) -eq 1 ]]; then
    echo "===> singli ..."
    KUBECONFIG=$(head -1 .kc)
    export KUBECONFIG
  else
    KC=$(mktemp /tmp/config-XXXXX)
    KUBECONFIG=$(sed -n 'H;$ {x;s/\n/:/gp;}' < .kc) 
    kubectl config view --flatten > $KC;
    export KUBECONFIG=$KC
  fi
  echo KUBECONFIG=$KUBECONFIG 1>&2
}

kunsecure() {
  cluster=$(kubectl config view --minify -o jsonpath='{.clusters[0].name}')
  kubectl config set-cluster $cluster --insecure-skip-tls-verify 
}

# sets default KUBECONFIG
kc() {
  local FIRST=${1:-$HOME/.kube/dummy}
  kcreset ${FIRST}
  export KUBECONFIG=$(echo ${FIRST} $HOME/.kube/${KCPATTERN:-*.yaml} |sed "s/ /:/g")
  kk
}
# resets ~/.kube/dummy in case it is messed up, or references a wrong context
kcreset() {
  local OUT=${1:-~/.kube/dummy}
  (KUBECONFIG=${OUT} kubectl config view)> ${OUT}
}

# creates temp KUBECONFIG: ctx changes don't effect other shells
kct-old() {
  KC=$(mktemp /tmp/config-XXXXX)
  kc $KC
}

kct-old() {
  KC=$(mktemp /tmp/config-XXXXX)
  KUBECONFIG=$(echo $HOME/.kube/${KCPATTERN:-*.yaml} |sed "s/ /:/g") \
    kubectl config view --flatten \
    > $KC
  export KUBECONFIG=$KC
}
kct() {
  KC=$(mktemp /tmp/config-XXXXX)
  kubectl config view --flatten > $KC
  export KUBECONFIG=$KC
}


kprompt() {
    kubectl config view --minify -o go-template='{{ printf "[%v/%v]"  (index . "current-context")  (index .contexts 0).context.namespace }}'
}

# creates temp KUBECONFIG: in a subshell
ksub() {
  OLDVC=$KC
  kct
  if declare -F kube_ps1 &>/dev/null; then 
    bash --rcfile <(echo -e "export KUBE_PS1_PREFIX='[${KC#*config-}]('\n. ~/.bashrc")
  else
    bash --rcfile <(echo -e ". ~/.bashrc \n export PS1='${KC#*config-} \$(kprompt)$ '")
  fi
  KC=$OLDVC
}