#!/bin/bash

# Copyright 2014 The Kubernetes Authors All rights reserved.
#
# 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.

# Verifies that services and virtual IPs work.

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

KUBE_ROOT=$(dirname "${BASH_SOURCE}")/../..

: ${KUBE_VERSION_ROOT:=${KUBE_ROOT}}
: ${KUBECTL:="${KUBE_VERSION_ROOT}/cluster/kubectl.sh"}
: ${KUBE_CONFIG_FILE:="config-test.sh"}

export KUBECTL KUBE_CONFIG_FILE

TEST_NAMESPACE="services-test-${RANDOM}"
KUBECTL="${KUBECTL} --namespace=${TEST_NAMESPACE}"

source "${KUBE_ROOT}/cluster/kube-env.sh"
source "${KUBE_VERSION_ROOT}/cluster/${KUBERNETES_PROVIDER}/util.sh"

prepare-e2e

function error() {
  echo "$@" >&2
  exit 1
}

function sort_args() {
  [ $# == 0 ] && return
  a=($(printf "%s\n" "$@" | sort -n))
  echo "${a[*]}"
}

# Join args $2... with $1 between them.
# Example: join ", " x y z   =>   x, y, z
function join() {
  local sep item
  sep=$1
  shift
  echo -n "${1:-}"
  shift
  for item; do
    echo -n "${sep}${item}"
  done
  echo
}

svcs_to_clean=()
function do_teardown() {
  ${KUBECTL} delete namespace "${TEST_NAMESPACE}"
}

function make_namespace() {
  echo "Making namespace '${TEST_NAMESPACE}'"
  ${KUBECTL} create -f - << __EOF__
{
    "kind": "Namespace",
    "apiVersion": "v1",
    "metadata": {
        "name": "${TEST_NAMESPACE}"
    }
}
__EOF__
}

wait_for_apiserver() {
  echo "Waiting for apiserver to be up"

  local i
  for i in $(seq 1 12); do
    results=$(ssh-to-node "${master}" "
      wget -q -T 1 -O - http://localhost:8080/healthz || true
    ")
    if [[ "${results}" == "ok" ]]; then
      return
    fi
    sleep 5  # wait for apiserver to restart
  done
  error "restarting apiserver timed out"
}

# Args:
#   $1: service name
#   $2: service port
#   $3: service replica count
function start_service() {
  echo "Starting service '${TEST_NAMESPACE}/$1' on port $2 with $3 replicas"
  svcs_to_clean+=("$1")
  ${KUBECTL} create -f - << __EOF__
{
  "kind": "ReplicationController",
  "apiVersion": "v1",
  "metadata": {
    "name": "$1",
    "labels": {
      "name": "$1"
    }
  },
  "spec": {
    "replicas": $3,
    "selector": {
      "name": "$1"
    },
    "template": {
      "metadata": {
        "labels": {
          "name": "$1"
        }
      },
      "spec": {
        "containers": [
          {
            "name": "$1",
            "image": "gcr.io/google_containers/serve_hostname:1.1",
            "ports": [
              {
                "containerPort": 9376,
                "protocol": "TCP"
              }
            ]
          }
        ]
      }
    }
  }
}
__EOF__
  ${KUBECTL} create -f - << __EOF__
{
  "kind": "Service",
  "apiVersion": "v1",
  "metadata": {
    "name": "$1",
    "labels": {
      "name": "$1"
    }
  },
  "spec": {
    "ports": [
      {
        "protocol": "TCP",
        "port": $2,
        "targetPort": 9376
      }
    ],
    "selector": {
      "name": "$1"
    }
  }
}
__EOF__
}

# Args:
#   $1: service name
function stop_service() {
  echo "Stopping service '$1'"
  ${KUBECTL} stop rc "$1" || true
  ${KUBECTL} delete services "$1" || true
}

# Args:
#   $1: service name
#   $2: expected pod count
function query_pods() {
  # This fails very occasionally, so retry a bit.
  local pods_unsorted=()
  local i
  for i in $(seq 1 10); do
    pods_unsorted=($(${KUBECTL} get pods -o template \
        '--template={{range.items}}{{.metadata.name}} {{end}}' \
        '--api-version=v1' \
        -l name="$1"))
    found="${#pods_unsorted[*]}"
    if [[ "${found}" == "$2" ]]; then
      break
    fi
    sleep 3
  done
  if [[ "${found}" != "$2" ]]; then
    error "Failed to query pods for $1: expected $2, found ${found}"
  fi

  # The "return" is a sorted list of pod IDs.
  sort_args "${pods_unsorted[@]}"
}

# Args:
#   $1: service name
#   $2: pod count
function wait_for_pods() {
  echo "Querying pods in $1"
  local pods_sorted=$(query_pods "$1" "$2")
  printf '\t%s\n' ${pods_sorted}

  # Container turn up on a clean cluster can take a while for the docker image
  # pulls.  Wait a generous amount of time.
  # TODO: Sometimes pods change underneath us, which makes the GET fail (404).
  # Maybe this test can be loosened and still be useful?
  pods_needed=$2
  local i
  for i in $(seq 1 30); do
    echo "Waiting for ${pods_needed} pods to become 'running'"
    pods_needed="$2"
    for id in ${pods_sorted}; do
      status=$(${KUBECTL} get pods "${id}" -o template --template='{{.status.phase}}' --api-version=v1)
      if [[ "${status}" == "Running" ]]; then
        pods_needed=$((pods_needed-1))
      fi
    done
    if [[ "${pods_needed}" == 0 ]]; then
      break
    fi
    sleep 3
  done
  if [[ "${pods_needed}" -gt 0 ]]; then
    error "Pods for $1 did not come up in time"
  fi
}

# Args:
#   $1: service name
#   $2: service IP
#   $3: service port
#   $4: pod count
#   $5: pod IDs (sorted)
function wait_for_service_up() {
  local i
  local found_pods
  echo "waiting for $1 at $2:$3"
  # TODO: Reduce this interval once we have a sense for the latency distribution.
  for i in $(seq 1 10); do
    results=($(ssh-to-node "${test_node}" "
        set -e;
        for i in $(seq -s' ' 1 $(($4*3))); do
          wget -q -T 1 -O - http://$2:$3 || true;
          echo;
        done | sort -n | uniq
        "))

    found_pods=$(sort_args "${results[@]:+${results[@]}}")
    if [[ "${found_pods}" == "$5" ]]; then
      return
    fi
    echo "expected '$5', got '${found_pods}': will try again"
    sleep 5  # wait for endpoints to propagate
  done
  error "$1: failed to verify portal from host"
}

# Args:
#   $1: service name
#   $2: service IP
#   $3: service port
function wait_for_service_down() {
  local i
  for i in $(seq 1 15); do
    $(ssh-to-node "${test_node}" "
        curl -s --connect-timeout 2 "http://$2:$3" >/dev/null 2>&1 && exit 1 || exit 0;
        ") && break
    echo "Waiting for $1 to go down"
    sleep 2
  done
}

# Args:
#   $1: service name
#   $2: service IP
#   $3: service port
#   $4: pod count
#   $5: pod IDs (sorted)
function verify_from_container() {
  local i
  local found_pods
  echo "waiting for $1 at $2:$3"
  # TODO: Reduce this interval once we have a sense for the latency distribution.
  for i in $(seq 1 10); do
    results=($(ssh-to-node "${test_node}" "
        set -e;
        sudo docker pull gcr.io/google_containers/busybox >/dev/null;
        sudo docker run gcr.io/google_containers/busybox sh -c '
            for i in $(seq -s' ' 1 $(($4*3))); do
              wget -q -T 1 -O - http://$2:$3 || true;
              echo;
            done
        '" | sort -n | uniq))

    found_pods=$(sort_args "${results[@]:+${results[@]}}")
    if [[ "${found_pods}" == "$5" ]]; then
      return
    fi
    echo "expected '$5', got '${found_pods}': will try again"
    sleep 5  # wait for endpoints to propagate
  done
  error "$1: failed to verify portal from host"
}

trap do_teardown EXIT

# Get node IP addresses and pick one as our test point.
detect-minions
test_node="${MINION_NAMES[0]}"
master="${MASTER_NAME}"

# Make our namespace
make_namespace

# Launch some pods and services.
svc1_name="service1"
svc1_port=80
svc1_count=3
start_service "${svc1_name}" "${svc1_port}" "${svc1_count}"

svc2_name="service2"
svc2_port=80
svc2_count=3
start_service "${svc2_name}" "${svc2_port}" "${svc2_count}"

# Wait for the pods to become "running".
wait_for_pods "${svc1_name}" "${svc1_count}"
wait_for_pods "${svc2_name}" "${svc2_count}"

# Get the sorted lists of pods.
svc1_pods=$(query_pods "${svc1_name}" "${svc1_count}")
svc2_pods=$(query_pods "${svc2_name}" "${svc2_count}")

# Get the VIP IPs.
svc1_ip=$(${KUBECTL} get services -o template '--template={{.spec.clusterIP}}' "${svc1_name}" --api-version=v1)
test -n "${svc1_ip}" || error "Service1 IP is blank"
svc2_ip=$(${KUBECTL} get services -o template '--template={{.spec.clusterIP}}' "${svc2_name}" --api-version=v1)
test -n "${svc2_ip}" || error "Service2 IP is blank"
if [[ "${svc1_ip}" == "${svc2_ip}" ]]; then
  error "VIPs conflict: ${svc1_ip}"
fi

#
# Test 1: Prove that the service VIP is alive.
#
echo "Test 1: Prove that the service VIP is alive."
echo "Verifying the VIP from the host"
wait_for_service_up "${svc1_name}" "${svc1_ip}" "${svc1_port}" \
    "${svc1_count}" "${svc1_pods}"
wait_for_service_up "${svc2_name}" "${svc2_ip}" "${svc2_port}" \
    "${svc2_count}" "${svc2_pods}"
echo "Verifying the VIP from a container"
verify_from_container "${svc1_name}" "${svc1_ip}" "${svc1_port}" \
    "${svc1_count}" "${svc1_pods}"
verify_from_container "${svc2_name}" "${svc2_ip}" "${svc2_port}" \
    "${svc2_count}" "${svc2_pods}"

#
# Test 2: Bounce the proxy and make sure the VIP comes back.
#
echo "Test 2: Bounce the proxy and make sure the VIP comes back."
echo "Restarting kube-proxy"
restart-kube-proxy "${test_node}"
echo "Verifying the VIP from the host"
wait_for_service_up "${svc1_name}" "${svc1_ip}" "${svc1_port}" \
    "${svc1_count}" "${svc1_pods}"
wait_for_service_up "${svc2_name}" "${svc2_ip}" "${svc2_port}" \
    "${svc2_count}" "${svc2_pods}"
echo "Verifying the VIP from a container"
verify_from_container "${svc1_name}" "${svc1_ip}" "${svc1_port}" \
    "${svc1_count}" "${svc1_pods}"
verify_from_container "${svc2_name}" "${svc2_ip}" "${svc2_port}" \
    "${svc2_count}" "${svc2_pods}"

#
# Test 3: Stop one service and make sure it is gone.
#
echo "Test 3: Stop one service and make sure it is gone."
stop_service "${svc1_name}"
wait_for_service_down "${svc1_name}" "${svc1_ip}" "${svc1_port}"

#
# Test 4: Bring up another service.
# TODO: Actually add a test to force re-use.
#
echo "Test 4: Bring up another service."
svc3_name="service3"
svc3_port=80
svc3_count=3
start_service "${svc3_name}" "${svc3_port}" "${svc3_count}"

# Wait for the pods to become "running".
wait_for_pods "${svc3_name}" "${svc3_count}"

# Get the sorted lists of pods.
svc3_pods=$(query_pods "${svc3_name}" "${svc3_count}")

# Get the VIP.
svc3_ip=$(${KUBECTL} get services -o template '--template={{.spec.clusterIP}}' "${svc3_name}" --api-version=v1)
test -n "${svc3_ip}" || error "Service3 IP is blank"

echo "Verifying the VIPs from the host"
wait_for_service_up "${svc3_name}" "${svc3_ip}" "${svc3_port}" \
    "${svc3_count}" "${svc3_pods}"
echo "Verifying the VIPs from a container"
verify_from_container "${svc3_name}" "${svc3_ip}" "${svc3_port}" \
    "${svc3_count}" "${svc3_pods}"

#
# Test 5: Remove the iptables rules, make sure they come back.
#
echo "Test 5: Remove the iptables rules, make sure they come back."
echo "Manually removing iptables rules"
# Remove both the new and old style chains, in case we're testing on an old kubelet
ssh-to-node "${test_node}" "sudo iptables -t nat -F KUBE-PORTALS-HOST || true"
ssh-to-node "${test_node}" "sudo iptables -t nat -F KUBE-PORTALS-CONTAINER || true"
echo "Verifying the VIPs from the host"
wait_for_service_up "${svc3_name}" "${svc3_ip}" "${svc3_port}" \
    "${svc3_count}" "${svc3_pods}"
echo "Verifying the VIPs from a container"
verify_from_container "${svc3_name}" "${svc3_ip}" "${svc3_port}" \
    "${svc3_count}" "${svc3_pods}"

#
# Test 6: Restart the master, make sure VIPs come back.
#
echo "Test 6: Restart the master, make sure VIPs come back."
echo "Restarting the master"
restart-apiserver "${master}"
wait_for_apiserver
echo "Verifying the VIPs from the host"
wait_for_service_up "${svc3_name}" "${svc3_ip}" "${svc3_port}" \
    "${svc3_count}" "${svc3_pods}"
echo "Verifying the VIPs from a container"
verify_from_container "${svc3_name}" "${svc3_ip}" "${svc3_port}" \
    "${svc3_count}" "${svc3_pods}"

#
# Test 7: Bring up another service, make sure it does not re-use IPs.
#
echo "Test 7: Bring up another service, make sure it does not re-use IPs."
svc4_name="service4"
svc4_port=80
svc4_count=3
start_service "${svc4_name}" "${svc4_port}" "${svc4_count}"

# Wait for the pods to become "running".
wait_for_pods "${svc4_name}" "${svc4_count}"

# Get the sorted lists of pods.
svc4_pods=$(query_pods "${svc4_name}" "${svc4_count}")

# Get the VIP.
svc4_ip=$(${KUBECTL} get services -o template '--template={{.spec.clusterIP}}' "${svc4_name}" --api-version=v1)
test -n "${svc4_ip}" || error "Service4 IP is blank"
if [[ "${svc4_ip}" == "${svc2_ip}" || "${svc4_ip}" == "${svc3_ip}" ]]; then
  error "VIPs conflict: ${svc4_ip}"
fi

echo "Verifying the VIPs from the host"
wait_for_service_up "${svc4_name}" "${svc4_ip}" "${svc4_port}" \
    "${svc4_count}" "${svc4_pods}"
echo "Verifying the VIPs from a container"
verify_from_container "${svc4_name}" "${svc4_ip}" "${svc4_port}" \
    "${svc4_count}" "${svc4_pods}"

exit 0