ceph-csi/vendor/k8s.io/kubernetes/cluster/addons/addon-manager/kube-addons.sh
2018-07-31 14:53:26 +02:00

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#!/usr/bin/env bash
# Copyright 2014 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.
# LIMITATIONS
# 1. Exit code is probably not always correct.
# 2. There are no unittests.
# 3. Will not work if the total length of paths to addons is greater than
# bash can handle. Probably it is not a problem: ARG_MAX=2097152 on GCE.
# cosmetic improvements to be done
# 1. Improve the log function; add timestamp, file name, etc.
# 2. Logging doesn't work from files that print things out.
# 3. Kubectl prints the output to stderr (the output should be captured and then
# logged)
KUBECTL=${KUBECTL_BIN:-/usr/local/bin/kubectl}
KUBECTL_OPTS=${KUBECTL_OPTS:-}
ADDON_CHECK_INTERVAL_SEC=${TEST_ADDON_CHECK_INTERVAL_SEC:-60}
ADDON_PATH=${ADDON_PATH:-/etc/kubernetes/addons}
SYSTEM_NAMESPACE=kube-system
# Addons could use this label with two modes:
# - ADDON_MANAGER_LABEL=Reconcile
# - ADDON_MANAGER_LABEL=EnsureExists
ADDON_MANAGER_LABEL="addonmanager.kubernetes.io/mode"
# This label is deprecated (only for Addon Manager). In future release
# addon-manager may not respect it anymore. Addons with
# CLUSTER_SERVICE_LABEL=true and without ADDON_MANAGER_LABEL=EnsureExists
# will be reconciled for now.
CLUSTER_SERVICE_LABEL="kubernetes.io/cluster-service"
# Whether only one addon manager should be running in a multi-master setup.
# Disabling this flag will force all addon managers to assume they are the
# leaders.
ADDON_MANAGER_LEADER_ELECTION=${ADDON_MANAGER_LEADER_ELECTION:-true}
# Remember that you can't log from functions that print some output (because
# logs are also printed on stdout).
# $1 level
# $2 message
function log() {
# manage log levels manually here
# add the timestamp if you find it useful
case $1 in
DB3 )
# echo "$1: $2"
;;
DB2 )
# echo "$1: $2"
;;
DBG )
# echo "$1: $2"
;;
INFO )
echo "$1: $2"
;;
WRN )
echo "$1: $2"
;;
ERR )
echo "$1: $2"
;;
* )
echo "INVALID_LOG_LEVEL $1: $2"
;;
esac
}
# $1 filename of addon to start.
# $2 count of tries to start the addon.
# $3 delay in seconds between two consecutive tries
# $4 namespace
function start_addon() {
local -r addon_filename=$1;
local -r tries=$2;
local -r delay=$3;
local -r namespace=$4
create_resource_from_string "$(cat ${addon_filename})" "${tries}" "${delay}" "${addon_filename}" "${namespace}"
}
# $1 string with json or yaml.
# $2 count of tries to start the addon.
# $3 delay in seconds between two consecutive tries
# $4 name of this object to use when logging about it.
# $5 namespace for this object
function create_resource_from_string() {
local -r config_string=$1;
local tries=$2;
local -r delay=$3;
local -r config_name=$4;
local -r namespace=$5;
while [ ${tries} -gt 0 ]; do
echo "${config_string}" | ${KUBECTL} ${KUBECTL_OPTS} --namespace="${namespace}" apply -f - && \
log INFO "== Successfully started ${config_name} in namespace ${namespace} at $(date -Is)" && \
return 0;
let tries=tries-1;
log WRN "== Failed to start ${config_name} in namespace ${namespace} at $(date -Is). ${tries} tries remaining. =="
sleep ${delay};
done
return 1;
}
function reconcile_addons() {
# TODO: Remove the first command in future release.
# Adding this for backward compatibility. Old addons have CLUSTER_SERVICE_LABEL=true and don't have
# ADDON_MANAGER_LABEL=EnsureExists will still be reconciled.
# Filter out `configured` message to not noisily log.
# `created`, `pruned` and errors will be logged.
log INFO "== Reconciling with deprecated label =="
${KUBECTL} ${KUBECTL_OPTS} apply -f ${ADDON_PATH} \
-l ${CLUSTER_SERVICE_LABEL}=true,${ADDON_MANAGER_LABEL}!=EnsureExists \
--prune=true --recursive | grep -v configured
log INFO "== Reconciling with addon-manager label =="
${KUBECTL} ${KUBECTL_OPTS} apply -f ${ADDON_PATH} \
-l ${CLUSTER_SERVICE_LABEL}!=true,${ADDON_MANAGER_LABEL}=Reconcile \
--prune=true --recursive | grep -v configured
log INFO "== Kubernetes addon reconcile completed at $(date -Is) =="
}
function ensure_addons() {
# Create objects already exist should fail.
# Filter out `AlreadyExists` message to not noisily log.
${KUBECTL} ${KUBECTL_OPTS} create -f ${ADDON_PATH} \
-l ${ADDON_MANAGER_LABEL}=EnsureExists --recursive 2>&1 | grep -v AlreadyExists
log INFO "== Kubernetes addon ensure completed at $(date -Is) =="
}
function is_leader() {
# In multi-master setup, only one addon manager should be running. We use
# existing leader election in kube-controller-manager instead of implementing
# a separate mechanism here.
if ! $ADDON_MANAGER_LEADER_ELECTION; then
log INFO "Leader election disabled."
return 0;
fi
KUBE_CONTROLLER_MANAGER_LEADER=`${KUBECTL} -n kube-system get ep kube-controller-manager \
-o go-template=$'{{index .metadata.annotations "control-plane.alpha.kubernetes.io/leader"}}' \
| sed 's/^.*"holderIdentity":"\([^"]*\)".*/\1/' | awk -F'_' '{print $1}'`
# If there was any problem with getting the leader election results, var will
# be empty. Since it's better to have multiple addon managers than no addon
# managers at all, we're going to assume that we're the leader in such case.
log INFO "Leader is $KUBE_CONTROLLER_MANAGER_LEADER"
[[ "$KUBE_CONTROLLER_MANAGER_LEADER" == "" ||
"$HOSTNAME" == "$KUBE_CONTROLLER_MANAGER_LEADER" ]]
}
# The business logic for whether a given object should be created
# was already enforced by salt, and /etc/kubernetes/addons is the
# managed result is of that. Start everything below that directory.
log INFO "== Kubernetes addon manager started at $(date -Is) with ADDON_CHECK_INTERVAL_SEC=${ADDON_CHECK_INTERVAL_SEC} =="
# Create the namespace that will be used to host the cluster-level add-ons.
start_addon /opt/namespace.yaml 100 10 "" &
# Wait for the default service account to be created in the kube-system namespace.
token_found=""
while [ -z "${token_found}" ]; do
sleep .5
token_found=$(${KUBECTL} ${KUBECTL_OPTS} get --namespace="${SYSTEM_NAMESPACE}" serviceaccount default -o go-template="{{with index .secrets 0}}{{.name}}{{end}}")
if [[ $? -ne 0 ]]; then
token_found="";
log WRN "== Error getting default service account, retry in 0.5 second =="
fi
done
log INFO "== Default service account in the ${SYSTEM_NAMESPACE} namespace has token ${token_found} =="
# Create admission_control objects if defined before any other addon services. If the limits
# are defined in a namespace other than default, we should still create the limits for the
# default namespace.
for obj in $(find /etc/kubernetes/admission-controls \( -name \*.yaml -o -name \*.json \)); do
start_addon "${obj}" 100 10 default &
log INFO "++ obj ${obj} is created ++"
done
# Start the apply loop.
# Check if the configuration has changed recently - in case the user
# created/updated/deleted the files on the master.
log INFO "== Entering periodical apply loop at $(date -Is) =="
while true; do
start_sec=$(date +"%s")
if is_leader; then
ensure_addons
reconcile_addons
else
log INFO "Not elected leader, going back to sleep."
fi
end_sec=$(date +"%s")
len_sec=$((${end_sec}-${start_sec}))
# subtract the time passed from the sleep time
if [[ ${len_sec} -lt ${ADDON_CHECK_INTERVAL_SEC} ]]; then
sleep_time=$((${ADDON_CHECK_INTERVAL_SEC}-${len_sec}))
sleep ${sleep_time}
fi
done