#!/bin/bash

# Copyright 2015 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.

# !!!EXPERIMENTAL !!! Upgrade script for GCE. Expect this to get
# rewritten in Go in relatively short order, but it allows us to start
# testing the concepts.

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

if [[ "${KUBERNETES_PROVIDER:-gce}" != "gce" ]]; then
  echo "!!! ${1} only works on GCE" >&2
  exit 1
fi

KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..
source "${KUBE_ROOT}/hack/lib/util.sh"
source "${KUBE_ROOT}/cluster/kube-util.sh"

function usage() {
  echo "!!! EXPERIMENTAL !!!"
  echo ""
  echo "${0} [-M | -N | -P] [-o] (-l | <version number or publication>)"
  echo "  Upgrades master and nodes by default"
  echo "  -M:  Upgrade master only"
  echo "  -N:  Upgrade nodes only"
  echo "  -P:  Node upgrade prerequisites only (create a new instance template)"
  echo "  -c:  Upgrade NODE_UPGRADE_PARALLELISM nodes in parallel (default=1) within a single instance group. The MIGs themselves are dealt serially."
  echo "  -o:  Use os distro sepcified in KUBE_NODE_OS_DISTRIBUTION for new nodes. Options include 'debian' or 'gci'"
  echo "  -l:  Use local(dev) binaries. This is only supported for master upgrades."
  echo ""
  echo '  Version number or publication is either a proper version number'
  echo '  (e.g. "v1.0.6", "v1.2.0-alpha.1.881+376438b69c7612") or a version'
  echo '  publication of the form <bucket>/<version> (e.g. "release/stable",'
  echo '  "ci/latest-1").  Some common ones are:'
  echo '    - "release/stable"'
  echo '    - "release/latest"'
  echo '    - "ci/latest"'
  echo '  See the docs on getting builds for more information about version publication.'
  echo ""
  echo "(... Fetching current release versions ...)"
  echo ""

  # NOTE: IF YOU CHANGE THE FOLLOWING LIST, ALSO UPDATE test/e2e/cluster_upgrade.go
  local release_stable
  local release_latest
  local ci_latest

  release_stable=$(gsutil cat gs://kubernetes-release/release/stable.txt)
  release_latest=$(gsutil cat gs://kubernetes-release/release/latest.txt)
  ci_latest=$(gsutil cat gs://kubernetes-release-dev/ci/latest.txt)

  echo "Right now, versions are as follows:"
  echo "  release/stable: ${0} ${release_stable}"
  echo "  release/latest: ${0} ${release_latest}"
  echo "  ci/latest:      ${0} ${ci_latest}"
}

function print-node-version-info() {
  echo "== $1 Node OS and Kubelet Versions =="
  "${KUBE_ROOT}/cluster/kubectl.sh" get nodes -o=jsonpath='{range .items[*]}name: "{.metadata.name}", osImage: "{.status.nodeInfo.osImage}", kubeletVersion: "{.status.nodeInfo.kubeletVersion}"{"\n"}{end}'
}

function upgrade-master() {
  local num_masters
  num_masters=$(get-master-replicas-count)
  if [[ "${num_masters}" -gt 1 ]]; then
    echo "Upgrade of master not supported if more than one master replica present. The current number of master replicas: ${num_masters}"
    exit 1
  fi

  echo "== Upgrading master to '${SERVER_BINARY_TAR_URL}'. Do not interrupt, deleting master instance. =="

  # Tries to figure out KUBE_USER/KUBE_PASSWORD by first looking under
  # kubeconfig:username, and then under kubeconfig:username-basic-auth.
  # TODO: KUBE_USER is used in generating ABAC policy which the
  # apiserver may not have enabled. If it's enabled, we must have a user
  # to generate a valid ABAC policy. If the username changes, should
  # the script fail? Should we generate a default username and password
  # if the section is missing in kubeconfig? Handle this better in 1.5.
  get-kubeconfig-basicauth
  get-kubeconfig-bearertoken

  detect-master
  parse-master-env
  upgrade-master-env

  backfile-kubeletauth-certs

  # Delete the master instance. Note that the master-pd is created
  # with auto-delete=no, so it should not be deleted.
  gcloud compute instances delete \
    --project "${PROJECT}" \
    --quiet \
    --zone "${ZONE}" \
    "${MASTER_NAME}"

  create-master-instance "${MASTER_NAME}-ip"
  wait-for-master
}

function upgrade-master-env() {
  echo "== Upgrading master environment variables. =="
  # Generate the node problem detector token if it isn't present on the original
  # master.
 if [[ "${ENABLE_NODE_PROBLEM_DETECTOR:-}" == "standalone" && "${NODE_PROBLEM_DETECTOR_TOKEN:-}" == "" ]]; then
    NODE_PROBLEM_DETECTOR_TOKEN=$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64 | tr -d "=+/" | dd bs=32 count=1 2>/dev/null)
  fi
}

# TODO(mikedanese): delete when we don't support < 1.6
function backfile-kubeletauth-certs() {
  if [[ ! -z "${KUBEAPISERVER_CERT_BASE64:-}" && ! -z "${KUBEAPISERVER_CERT_BASE64:-}" ]]; then
    return 0
  fi

  mkdir -p "${KUBE_TEMP}/pki"
  echo "${CA_KEY_BASE64}" | base64 -d > "${KUBE_TEMP}/pki/ca.key"
  echo "${CA_CERT_BASE64}" | base64 -d > "${KUBE_TEMP}/pki/ca.crt"
  (cd "${KUBE_TEMP}/pki"
    kube::util::ensure-cfssl "${KUBE_TEMP}/cfssl"
    cat <<EOF > ca-config.json
{
  "signing": {
    "client": {
      "expiry": "43800h",
      "usages": [
        "signing",
        "key encipherment",
        "client auth"
      ]
    }
  }
}
EOF
    # the name kube-apiserver is bound to the node proxy
    # subpaths required for the apiserver to hit proxy
    # endpoints on the kubelet's handler.
    cat <<EOF \
      | "${CFSSL_BIN}" gencert \
        -ca=ca.crt \
        -ca-key=ca.key \
        -config=ca-config.json \
        -profile=client \
        - \
      | "${CFSSLJSON_BIN}" -bare kube-apiserver
{
  "CN": "kube-apiserver"
}
EOF
  )
  KUBEAPISERVER_CERT_BASE64=$(cat "${KUBE_TEMP}/pki/kube-apiserver.pem" | base64 | tr -d '\r\n')
  KUBEAPISERVER_KEY_BASE64=$(cat "${KUBE_TEMP}/pki/kube-apiserver-key.pem" | base64 | tr -d '\r\n')
}

function wait-for-master() {
  echo "== Waiting for new master to respond to API requests =="

  local curl_auth_arg
  if [[ -n ${KUBE_BEARER_TOKEN:-} ]]; then
    curl_auth_arg=(-H "Authorization: Bearer ${KUBE_BEARER_TOKEN}")
  elif [[ -n ${KUBE_PASSWORD:-} ]]; then
    curl_auth_arg=(--user "${KUBE_USER}:${KUBE_PASSWORD}")
  else
    echo "can't get auth credentials for the current master"
    exit 1
  fi

  until curl --insecure "${curl_auth_arg[@]}" --max-time 5 \
    --fail --output /dev/null --silent "https://${KUBE_MASTER_IP}/healthz"; do
    printf "."
    sleep 2
  done

  echo "== Done =="
}

# Perform common upgrade setup tasks
#
# Assumed vars
#   KUBE_VERSION
function prepare-upgrade() {
  kube::util::ensure-temp-dir
  detect-project
  detect-subnetworks
  detect-node-names # sets INSTANCE_GROUPS
  write-cluster-name
  tars_from_version
}

# Reads kube-env metadata from first node in NODE_NAMES.
#
# Assumed vars:
#   NODE_NAMES
#   PROJECT
#   ZONE
function get-node-env() {
  # TODO(zmerlynn): Make this more reliable with retries.
  gcloud compute --project ${PROJECT} ssh --zone ${ZONE} ${NODE_NAMES[0]} --command \
    "curl --fail --silent -H 'Metadata-Flavor: Google' \
      'http://metadata/computeMetadata/v1/instance/attributes/kube-env'" 2>/dev/null
}

# Read os distro information from /os/release on node.
# $1: The name of node
#
# Assumed vars:
#   PROJECT
#   ZONE
function get-node-os() {
  gcloud compute ssh "$1" \
    --project "${PROJECT}" \
    --zone "${ZONE}" \
    --command \
    "cat /etc/os-release | grep \"^ID=.*\" | cut -c 4-"
}

# Assumed vars:
#   KUBE_VERSION
#   NODE_SCOPES
#   NODE_INSTANCE_PREFIX
#   PROJECT
#   ZONE
#
# Vars set:
#   KUBELET_TOKEN
#   KUBE_PROXY_TOKEN
#   NODE_PROBLEM_DETECTOR_TOKEN
#   CA_CERT_BASE64
#   EXTRA_DOCKER_OPTS
#   KUBELET_CERT_BASE64
#   KUBELET_KEY_BASE64
function upgrade-nodes() {
  prepare-node-upgrade
  do-node-upgrade
}

function setup-base-image() {
  if [[ "${env_os_distro}" == "false" ]]; then
    echo "== Ensuring that new Node base OS image matched the existing Node base OS image"
    NODE_OS_DISTRIBUTION=$(get-node-os "${NODE_NAMES[0]}")

    if [[ "${NODE_OS_DISTRIBUTION}" == "cos" ]]; then
        NODE_OS_DISTRIBUTION="gci"
    fi
    
    source "${KUBE_ROOT}/cluster/gce/${NODE_OS_DISTRIBUTION}/node-helper.sh"
    # Reset the node image based on current os distro
    set-node-image
  fi
}

# prepare-node-upgrade creates a new instance template suitable for upgrading
# to KUBE_VERSION and echos a single line with the name of the new template.
#
# Assumed vars:
#   KUBE_VERSION
#   NODE_SCOPES
#   NODE_INSTANCE_PREFIX
#   PROJECT
#   ZONE
#
# Vars set:
#   SANITIZED_VERSION
#   INSTANCE_GROUPS
#   KUBELET_TOKEN
#   KUBE_PROXY_TOKEN
#   NODE_PROBLEM_DETECTOR_TOKEN
#   CA_CERT_BASE64
#   EXTRA_DOCKER_OPTS
#   KUBELET_CERT_BASE64
#   KUBELET_KEY_BASE64
function prepare-node-upgrade() {
  echo "== Preparing node upgrade (to ${KUBE_VERSION}). ==" >&2
  setup-base-image

  SANITIZED_VERSION=$(echo ${KUBE_VERSION} | sed 's/[\.\+]/-/g')

  # TODO(zmerlynn): Refactor setting scope flags.
  local scope_flags=
  if [ -n "${NODE_SCOPES}" ]; then
    scope_flags="--scopes ${NODE_SCOPES}"
  else
    scope_flags="--no-scopes"
  fi

  # Get required node env vars from exiting template.
  local node_env=$(get-node-env)
  KUBELET_TOKEN=$(get-env-val "${node_env}" "KUBELET_TOKEN")
  KUBE_PROXY_TOKEN=$(get-env-val "${node_env}" "KUBE_PROXY_TOKEN")
  NODE_PROBLEM_DETECTOR_TOKEN=$(get-env-val "${node_env}" "NODE_PROBLEM_DETECTOR_TOKEN")
  CA_CERT_BASE64=$(get-env-val "${node_env}" "CA_CERT")
  EXTRA_DOCKER_OPTS=$(get-env-val "${node_env}" "EXTRA_DOCKER_OPTS")
  KUBELET_CERT_BASE64=$(get-env-val "${node_env}" "KUBELET_CERT")
  KUBELET_KEY_BASE64=$(get-env-val "${node_env}" "KUBELET_KEY")

  upgrade-node-env

  # TODO(zmerlynn): How do we ensure kube-env is written in a ${version}-
  #                 compatible way?
  write-node-env

  # TODO(zmerlynn): Get configure-vm script from ${version}. (Must plumb this
  #                 through all create-node-instance-template implementations).
  local template_name=$(get-template-name-from-version ${SANITIZED_VERSION})
  create-node-instance-template "${template_name}"
  # The following is echo'd so that callers can get the template name.
  echo "Instance template name: ${template_name}"
  echo "== Finished preparing node upgrade (to ${KUBE_VERSION}). ==" >&2
}

function upgrade-node-env() {
  echo "== Upgrading node environment variables. =="
  # Get the node problem detector token from master if it isn't present on
  # the original node.
  if [[ "${ENABLE_NODE_PROBLEM_DETECTOR:-}" == "standalone" && "${NODE_PROBLEM_DETECTOR_TOKEN:-}" == "" ]]; then
    detect-master
    local master_env=$(get-master-env)
    NODE_PROBLEM_DETECTOR_TOKEN=$(get-env-val "${master_env}" "NODE_PROBLEM_DETECTOR_TOKEN")
  fi
}

# Upgrades a single node.
# $1: The name of the node
#
# Note: This is called multiple times from do-node-upgrade() in parallel, so should be thread-safe.
function do-single-node-upgrade() {
  local -r instance="$1"
  instance_id=$(gcloud compute instances describe "${instance}" \
    --format='get(id)' \
    --project="${PROJECT}" \
    --zone="${ZONE}" 2>&1) && describe_rc=$? || describe_rc=$?
  if [[ "${describe_rc}" != 0 ]]; then
    echo "== FAILED to describe ${instance} =="
    echo "${instance_id}"
    return ${describe_rc}
  fi

  # Drain node
  echo "== Draining ${instance}. == " >&2
  "${KUBE_ROOT}/cluster/kubectl.sh" drain --delete-local-data --force --ignore-daemonsets "${instance}" \
    && drain_rc=$? || drain_rc=$?
  if [[ "${drain_rc}" != 0 ]]; then
    echo "== FAILED to drain ${instance} =="
    return ${drain_rc}
  fi

  # Recreate instance
  echo "== Recreating instance ${instance}. ==" >&2
  recreate=$(gcloud compute instance-groups managed recreate-instances "${group}" \
    --project="${PROJECT}" \
    --zone="${ZONE}" \
    --instances="${instance}" 2>&1) && recreate_rc=$? || recreate_rc=$?
  if [[ "${recreate_rc}" != 0 ]]; then
    echo "== FAILED to recreate ${instance} =="
    echo "${recreate}"
    return ${recreate_rc}
  fi

  # Wait for instance to be recreated
  echo "== Waiting for instance ${instance} to be recreated. ==" >&2
  while true; do
    new_instance_id=$(gcloud compute instances describe "${instance}" \
      --format='get(id)' \
      --project="${PROJECT}" \
      --zone="${ZONE}" 2>&1) && describe_rc=$? || describe_rc=$?
    if [[ "${describe_rc}" != 0 ]]; then
      echo "== FAILED to describe ${instance} =="
      echo "${new_instance_id}"
      echo "  (Will retry.)"
    elif [[ "${new_instance_id}" == "${instance_id}" ]]; then
      echo -n .
    else
      echo "Instance ${instance} recreated."
      break
    fi
    sleep 1
  done

  # Wait for k8s node object to reflect new instance id
  echo "== Waiting for new node to be added to k8s.  ==" >&2
  while true; do
    external_id=$("${KUBE_ROOT}/cluster/kubectl.sh" get node "${instance}" --output=jsonpath='{.spec.externalID}' 2>&1) && kubectl_rc=$? || kubectl_rc=$?
    if [[ "${kubectl_rc}" != 0 ]]; then
      echo "== FAILED to get node ${instance} =="
      echo "${external_id}"
      echo "  (Will retry.)"
    elif [[ "${external_id}" == "${new_instance_id}" ]]; then
      echo "Node ${instance} recreated."
      break
    elif [[ "${external_id}" == "${instance_id}" ]]; then
      echo -n .
    else
      echo "Unexpected external_id '${external_id}' matches neither old ('${instance_id}') nor new ('${new_instance_id}')."
      echo "  (Will retry.)"
    fi
    sleep 1
  done

  # Wait for the node to not have SchedulingDisabled=True and also to have
  # Ready=True.
  echo "== Waiting for ${instance} to become ready. ==" >&2
  while true; do
    cordoned=$("${KUBE_ROOT}/cluster/kubectl.sh" get node "${instance}" --output='jsonpath={.status.conditions[?(@.type == "SchedulingDisabled")].status}')
    ready=$("${KUBE_ROOT}/cluster/kubectl.sh" get node "${instance}" --output='jsonpath={.status.conditions[?(@.type == "Ready")].status}')
    if [[ "${cordoned}" == 'True' ]]; then
      echo "Node ${instance} is still not ready: SchedulingDisabled=${ready}"
    elif [[ "${ready}" != 'True' ]]; then
      echo "Node ${instance} is still not ready: Ready=${ready}"
    else
      echo "Node ${instance} Ready=${ready}"
      break
    fi
    sleep 1
  done
}

# Prereqs:
# - prepare-node-upgrade should have been called successfully
function do-node-upgrade() {
  echo "== Upgrading nodes to ${KUBE_VERSION} with max parallelism of ${node_upgrade_parallelism}. ==" >&2
  # Do the actual upgrade.
  # NOTE(zmerlynn): If you are changing this gcloud command, update
  #                 test/e2e/cluster_upgrade.go to match this EXACTLY.
  local template_name=$(get-template-name-from-version ${SANITIZED_VERSION})
  local old_templates=()
  local updates=()
  for group in ${INSTANCE_GROUPS[@]}; do
    old_templates+=($(gcloud compute instance-groups managed list \
        --project="${PROJECT}" \
        --filter="name ~ '${group}' AND zone:(${ZONE})" \
        --format='value(instanceTemplate)' || true))
    set_instance_template_out=$(gcloud compute instance-groups managed set-instance-template "${group}" \
      --template="${template_name}" \
      --project="${PROJECT}" \
      --zone="${ZONE}" 2>&1) && set_instance_template_rc=$? || set_instance_template_rc=$?
    if [[ "${set_instance_template_rc}" != 0 ]]; then
      echo "== FAILED to set-instance-template for ${group} to ${template_name} =="
      echo "${set_instance_template_out}"
      return ${set_instance_template_rc}
    fi
    instances=()
    instances+=($(gcloud compute instance-groups managed list-instances "${group}" \
        --format='value(instance)' \
        --project="${PROJECT}" \
        --zone="${ZONE}" 2>&1)) && list_instances_rc=$? || list_instances_rc=$?
    if [[ "${list_instances_rc}" != 0 ]]; then
      echo "== FAILED to list instances in group ${group} =="
      echo "${instances}"
      return ${list_instances_rc}
    fi

    process_count_left=${node_upgrade_parallelism}
    pids=()
    ret_code_sum=0  # Should stay 0 in the loop iff all parallel node upgrades succeed.
    for instance in ${instances[@]}; do
      do-single-node-upgrade "${instance}" & pids+=("$!")

      # We don't want to run more than ${node_upgrade_parallelism} upgrades at a time,
      # so wait once we hit that many nodes. This isn't ideal, since one might take much
      # longer than the others, but it should help.
      process_count_left=$((process_count_left - 1))
      if [[ process_count_left -eq 0 || "${instance}" == "${instances[-1]}" ]]; then
        # Wait for each of the parallel node upgrades to finish.
        for pid in "${pids[@]}"; do
          wait $pid
          ret_code_sum=$(( ret_code_sum + $? ))
        done
        # Return even if at least one of the node upgrades failed.
        if [[ ${ret_code_sum} != 0 ]]; then
          echo "== Some of the ${node_upgrade_parallelism} parallel node upgrades failed. =="
          return ${ret_code_sum}
        fi
        process_count_left=${node_upgrade_parallelism}
      fi
    done
  done

  # Remove the old templates.
  echo "== Deleting old templates in ${PROJECT}. ==" >&2
  for tmpl in ${old_templates[@]}; do
    gcloud compute instance-templates delete \
        --quiet \
        --project="${PROJECT}" \
        "${tmpl}" || true
  done

  echo "== Finished upgrading nodes to ${KUBE_VERSION}. ==" >&2
}

master_upgrade=true
node_upgrade=true
node_prereqs=false
local_binaries=false
env_os_distro=false
node_upgrade_parallelism=1

while getopts ":MNPlcho" opt; do
  case ${opt} in
    M)
      node_upgrade=false
      ;;
    N)
      master_upgrade=false
      ;;
    P)
      node_prereqs=true
      ;;
    l)
      local_binaries=true
      ;;
    c)
      node_upgrade_parallelism=${NODE_UPGRADE_PARALLELISM:-1}
      ;;
    o)
      env_os_distro=true
      ;;
    h)
      usage
      exit 0
      ;;
    \?)
      echo "Invalid option: -$OPTARG" >&2
      usage
      exit 1
      ;;
  esac
done
shift $((OPTIND-1))

if [[ $# -gt 1 ]]; then
  echo "Error: Only one parameter (<version number or publication>) may be passed after the set of flags!" >&2
  usage
  exit 1
fi

if [[ $# -lt 1 ]] && [[ "${local_binaries}" == "false" ]]; then
  usage
  exit 1
fi

if [[ "${master_upgrade}" == "false" ]] && [[ "${node_upgrade}" == "false" ]]; then
  echo "Can't specify both -M and -N" >&2
  exit 1
fi

# prompt if etcd storage media type isn't set unless using etcd2 when doing master upgrade
if [[ -z "${STORAGE_MEDIA_TYPE:-}" ]] && [[ "${STORAGE_BACKEND:-}" != "etcd2" ]] && [[ "${master_upgrade}" == "true" ]]; then
  echo "The default etcd storage media type in 1.6 has changed from application/json to application/vnd.kubernetes.protobuf."
  echo "Documentation about the change can be found at https://kubernetes.io/docs/admin/etcd_upgrade."
  echo ""
  echo "ETCD2 DOES NOT SUPPORT PROTOBUF: If you wish to have to ability to downgrade to etcd2 later application/json must be used."
  echo ""
  echo "It's HIGHLY recommended that etcd be backed up before this step!!"
  echo ""
  echo "To enable using json, before running this script set:"
  echo "export STORAGE_MEDIA_TYPE=application/json"
  echo ""
  if [ -t 0 ] && [ -t 1 ]; then
    read -p "Would you like to continue with the new default, and lose the ability to downgrade to etcd2? [y/N] " confirm
    if [[ "${confirm}" != "y" ]]; then
      exit 1
    fi
  else
    echo "To enable using protobuf, before running this script set:"
    echo "export STORAGE_MEDIA_TYPE=application/vnd.kubernetes.protobuf"
    echo ""
    echo "STORAGE_MEDIA_TYPE must be specified when run non-interactively." >&2
    exit 1
  fi
fi

print-node-version-info "Pre-Upgrade"

if [[ "${local_binaries}" == "false" ]]; then
  set_binary_version ${1}
fi

prepare-upgrade

if [[ "${node_prereqs}" == "true" ]]; then
  prepare-node-upgrade
  exit 0
fi

if [[ "${master_upgrade}" == "true" ]]; then
  upgrade-master
fi

if [[ "${node_upgrade}" == "true" ]]; then
  if [[ "${local_binaries}" == "true" ]]; then
    echo "Upgrading nodes to local binaries is not yet supported." >&2
    exit 1
  else
    upgrade-nodes
  fi
fi

echo "== Validating cluster post-upgrade =="
"${KUBE_ROOT}/cluster/validate-cluster.sh"

print-node-version-info "Post-Upgrade"