#!/usr/bin/env bash
#  vim:ts=4:sts=4:sw=4:et
#
#  Author: Hari Sekhon
#  Date: 2021-02-25 10:10:53 +0000 (Thu, 25 Feb 2021)
#
#  https://github.com/HariSekhon/DevOps-Bash-tools
#
#  License: see accompanying Hari Sekhon LICENSE file
#
#  If you're using my code you're welcome to connect with me on LinkedIn and optionally send me feedback to help steer this or other code I publish
#
#  https://www.linkedin.com/in/HariSekhon
#

set -euo pipefail
[ -n "${DEBUG:-}" ] && set -x

# XXX: Edit this - hardcode for localized convenience
CONTEXT="${1:-MYCONTEXT}"
# if set will also set the namespace for extra convenience
NAMESPACE="${2:-}"
#NAMESPACE="jenkins"

tmpdir="/tmp/.kube"

mkdir -pv "$tmpdir"

default_kubeconfig="${HOME:-$(cd ~ && pwd)}/.kube/config"
original_kubeconfig="${KUBECONFIG:-$default_kubeconfig}"

# reload safety - do not source from new tmpdir - not necessary for direnv but useful for local sourcing tests
#if [[ "$original_kubeconfig" =~ $tmpdir ]]; then
#    echo "ignoring \$KUBECONFIG=$original_kubeconfig, using default home location $default_kubeconfig"
#    original_kubeconfig="$default_kubeconfig"
#fi

# isolate the kubernetes context to avoid a race condition affecting any other shells or scripts
# epoch is added because $$ and $PPID are direnv sub-processes and may be reused later, so using epoch to add uniqueness
epoch="$(date +%s)"
export KUBECONFIG="$tmpdir/config.${EUID:-${UID:-$(id -u)}}.$$.$epoch"

# load your real kube config to isolated staging area to source the context info
if [ -f "$original_kubeconfig" ]; then
    cp "$original_kubeconfig" "$KUBECONFIG"
elif [ -f "$default_kubeconfig" ]; then
    cp "$default_kubeconfig" "$KUBECONFIG"
elif [ -f "$PWD/.kube/config" ]; then
    cp "$PWD/.kube/config" "$KUBECONFIG"
else
    echo "WARNING: failed to find one of:

    $original_kubeconfig
    $default_kubeconfig
    $PWD/.kube/config
" >&2
fi

kubectl config use-context "$CONTEXT"

if [ -n "${NAMESPACE:-}" ]; then
    kubectl config set-context "$CONTEXT" --namespace "$NAMESPACE"
fi