#!/usr/bin/env bash

# Copyright 2021 The Kubernetes Authors.
#
# 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.


# This script installs a local kind cluster with a local container registry and the correct files mounted for using CAPD
# to test Cluster API.
# This script is a customized version of the kind_with_local_registry script supplied by the kind maintainers at
# https://kind.sigs.k8s.io/docs/user/local-registry/
# The modifications mount the docker socket inside the kind cluster so that CAPD can be used to
# created docker containers.

set -o errexit
set -o nounset
set -o pipefail

if [[ "${TRACE-0}" == "1" ]]; then
    set -o xtrace
fi

KIND_CLUSTER_NAME=${CAPI_KIND_CLUSTER_NAME:-"capi-test"}
# See: https://kind.sigs.k8s.io/docs/user/configuration/#ip-family
KIND_NETWORK_IPFAMILY=${KIND_NETWORK_IPFAMILY:-"dual"}

# 1. If kind cluster already exists exit.
if [[ "$(kind get clusters)" =~ .*"${KIND_CLUSTER_NAME}".* ]]; then
  echo "kind cluster already exists, moving on"
  exit 0
fi

# 2. Create registry container unless it already exists
reg_name='kind-registry'
reg_port='5000'
if [ "$(docker inspect -f '{{.State.Running}}' "${reg_name}" 2>/dev/null || true)" != 'true' ]; then
  docker run \
    -d --restart=always -p "127.0.0.1:${reg_port}:5000" --name "${reg_name}" \
    registry:2
fi

# 3. Create kind cluster with containerd registry config dir enabled.
# TODO(killianmuldoon): kind will eventually enable this by default and this patch will be unnecessary.
#
# See:
# https://github.com/kubernetes-sigs/kind/issues/2875
# https://github.com/containerd/containerd/blob/main/docs/cri/config.md#registry-configuration
# See: https://github.com/containerd/containerd/blob/main/docs/hosts.md
cat <<EOF | kind create cluster --name="$KIND_CLUSTER_NAME"  --config=-
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
networking:
  ipFamily: ${KIND_NETWORK_IPFAMILY}
nodes:
- role: control-plane
  extraMounts:
    - hostPath: /var/run/docker.sock
      containerPath: /var/run/docker.sock
containerdConfigPatches:
- |-
  [plugins."io.containerd.grpc.v1.cri".registry]
    config_path = "/etc/containerd/certs.d"
EOF

# 4. Add the registry config to the nodes
#
# This is necessary because localhost resolves to loopback addresses that are
# network-namespace local.
# In other words: localhost in the container is not localhost on the host.
#
# We want a consistent name that works from both ends, so we tell containerd to
# alias localhost:${reg_port} to the registry container when pulling images
REGISTRY_DIR="/etc/containerd/certs.d/localhost:${reg_port}"
for node in $(kind get nodes --name "$KIND_CLUSTER_NAME"); do
  docker exec "${node}" mkdir -p "${REGISTRY_DIR}"
  cat <<EOF | docker exec -i "${node}" cp /dev/stdin "${REGISTRY_DIR}/hosts.toml"
[host."http://${reg_name}:5000"]
EOF
done

# 5. Connect the registry to the cluster network if not already connected
# This allows kind to bootstrap the network but ensures they're on the same network
if [ "$(docker inspect -f='{{json .NetworkSettings.Networks.kind}}' "${reg_name}")" = 'null' ]; then
  docker network connect "kind" "${reg_name}"
fi

# 6. Document the local registry
# https://github.com/kubernetes/enhancements/tree/master/keps/sig-cluster-lifecycle/generic/1755-communicating-a-local-registry
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  name: local-registry-hosting
  namespace: kube-public
data:
  localRegistryHosting.v1: |
    host: "localhost:${reg_port}"
    help: "https://kind.sigs.k8s.io/docs/user/local-registry/"
EOF