update

#!/bin/bash
#
# Copyright 2018 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

################################################################################
# Usage:
#   update --name NAME --namespace NAMESPACE [--version VERSION]
#
# Update an existing KALM enabled application to a new version.
# If no --version is specified, it uses the latest available version
# on the Release object.
################################################################################

set -eo pipefail

for i in "$@"
do
case $i in
  --name=*)
    name="${i#*=}"
    shift
    ;;
  --namespace=*)
    namespace="${i#*=}"
    shift
    ;;
  --version=*)
    version="${i#*=}"
    shift
    ;;
  *)
    >&2 echo "Unrecognized flag: $i"
    exit 1
    ;;
esac
done

[[ -z "$name" ]] && >&2 echo "--name required" && exit 1
[[ -z "$namespace" ]] && >&2 echo "--namespace required" && exit 1

current_version="$( \
    kubectl --namespace="$namespace" get "Release.kalm.google.com/$name" -ojson \
    | jq -r '.spec.version')"

# If no version is explicitly specified, get the latest available versions.
if [[ -z "$version" ]]; then
  version="$( \
      kubectl --namespace="$namespace" get "Release.kalm.google.com/$name" -ojson \
      | jq -r '.status.availableVersions[0].version')"
  if [[ "$current_version" == "$version" ]]; then
    >&2 echo "No new version found. Current version: $current_version"
    exit
  fi
else
  if [[ "$current_version" == "$version" ]]; then
    >&2 echo "Already at version $current_version"
    exit
  fi
fi

>&2 echo "Updating from current version $current_version to latest version $version"

kubectl --namespace="$namespace" patch "Release.kalm.google.com" "$name" \
    --type=merge \
    -p "$(printf '{"spec":{"version":"%s"}}' "$version")"