Dump cluster state to YAML

kubescan.sh

#!/bin/bash

# USAGE
# kubescan.sh [kubeconfig.yaml] > state.yaml

# Goal:
# - Provide a quick way to dump the state of a cluster for analysis
# - Simplify verification of live state of the cluster

KUBECONFIG=${1:-$KUBECONFIG}

fail ()
{
  echo "$2" >&2

  # shellcheck disable=SC2086
  exit $1
}

kubedo ()
{
  kubectl --kubeconfig="$KUBECONFIG" -o yaml "$@"
}

yaml_doc ()
{
  echo '%YAML 1.1'
  echo '--- #' "$1"
  cat
  echo '...'
}

test -f "$KUBECONFIG" || fail 1 "Provide a valid kubeconfig file"

THINGS_TO_GET="$(kubectl get 2>&1 | \
                 grep -v 'all'    | \
                 grep -P '\s+\*'  | \
                 tr -d "'"        | \
                 perl -ln -e '
                    my @x;
                    s/^\s*//g;
                    tr/[\(\)\*]//d;
                    s/error:.*//;
                    my @x = split(/ /);
                    ( $x[3] ) ? print $x[3] : print $x[1]')"

# NOTE: the node details can be extremely useful, but may generate some redundant data with
# the other resource types below.
# kubedo get nodes | yaml_doc 'nodes'

# grab namespaces first mostly becuase
# the rest of the commands normalize amongst themselves
# but namespaces don't live in a namespace per se.
kubedo get ns | yaml_doc 'namespaces'

for kubeobj in $THINGS_TO_GET
do
  [[ "$kubeobj" == "ns" ]] && continue
  kubedo get "$kubeobj" --all-namespaces | yaml_doc "$kubeobj"
done