set-worker-parameters

#!/bin/bash

# Copyright 2020-2022 Robert Krawitz/Red Hat
#
# 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.

# Unfortunate that there's no way to tell shellcheck to always source
# specific files.
# shellcheck disable=SC2034

# See the bash change log, differences between 4.4-beta2 and 4.4-rc2:
# a.  Using ${a[@]} or ${a[*]} with an array without any assigned elements when
#     the nounset option is enabled no longer throws an unbound variable error.

declare -A args
declare argsSet=0
declare oconfig
declare -r configName='set-max-pods'
declare -i force=0
declare -i waitOnly=0
declare -i oldGeneration=0
declare -i newGeneration=0

function help() {
    cat <<EOF
Usage: $0 [options]
       -f              Attempt to force changes even if the config
                       appears unchanged
       -p maxPods      Maximum pods/node
       -b KubeAPIBurst Kubelet-apiserver burst queries/sec
       -q KubeAPIQPS   Kubelet-apiserver sustained queries/sec
       -X option=value Any other option and value
EOF
    exit 1
}

while getopts "fhp:b:q:X:" opt ; do
    case "$opt" in
	f) force=1				   ;;
	p) args[maxPods]="$OPTARG"; argsSet=1      ;;
	b) args[KubeAPIBurst]="$OPTARG"; argsSet=1 ;;
	q) args[KubeAPIQPS]="$OPTARG"; argsSet=1   ;;
	X)
	    option=${OPTARG%%=*}
	    value=${OPTARG#*=}
	    if [[ -n $value ]] ; then
		args[$option]=$value
		argsSet=1
	    else
		unset "args[$option]"
	    fi
	    ;;
	*) help				;;
    esac
done

if ((! argsSet )) ; then
    echo "No options set"
    help
fi

function get_var() {
    jq -r "[.$1?] | map (select (. != null) | tostring) |join(\"\")" <<< "$2"
}

function test_unchanged() {
    local k
    local v
    local -i changed=0
    for k in "${!args[@]}" ; do
	v="$(get_var "$k" "$1")"
	if [[ ${args[$k]} != "$v" ]] ; then
	    echo "$k ${v:-(null)} => ${args[$k]:-(null)}"
	    changed=1
	else
	    echo "$k $v (unchanged)"
	fi
    done
    if ((! changed)) ; then
	if ((force)) ; then
	    waitOnly=1
	else
	    echo "*** Kubeconfig is unchanged, not updating"
	    exit 0
	fi
    fi
}


oconfig="$(oc get kubeletconfig.machineconfiguration.openshift.io/$configName -ojson 2>/dev/null | jq '.spec.kubeletConfig')"
test_unchanged "$oconfig"

function get_machine_status() {
    oc get machineconfigpool worker -ojson | jq -r '[.metadata.name, (.metadata.generation | tostring), ([foreach .status.conditions[] as $cond ([[],[]];0; if ($cond.status == "True") then $cond.type else null end)] | flatten | map (select (. != null)) | join(" ")), (.status.machineCount | tostring), (.status.degradedMachineCount | tostring), (.status.readyMachineCount | tostring), (.status.unavailableMachineCount | tostring), (.status.updatedMachineCount | tostring)] | join("|")'
}

function tsec() {
    printf "%(%s)T" -1
}

function ptime() {
    local -i start=$1
    local -i interval="$(($(tsec) - start))"
    if (( interval >= 3600 )) ; then
	printf "%d:%02d:%02d" "$((interval / 3600))" "$(((interval % 3600) / 60))" "$((interval % 60))"
    else
	printf "%d:%02d" "$((interval / 60))" "$((interval % 60))"
    fi
}

if [[ $(oc get machineconfigpool worker -o json | jq -r '.metadata.labels."custom-kubelet"?' 2>/dev/null) != 'large-pods' ]] ; then
    oc label --overwrite machineconfigpool worker custom-kubelet=large-pods
fi

oldGeneration=$(oc get mcp worker -ojsonpath='{.status.observedGeneration}')
oc apply -f - <<EOF
apiVersion: machineconfiguration.openshift.io/v1
kind: KubeletConfig
metadata:
  name: "$configName"
spec:
  machineConfigPoolSelector:
    matchLabels:
      custom-kubelet: large-pods
  kubeletConfig:
    apiVersion: machineconfiguration.openshift.io/v1
    kind: KubeletConfig
$(for arg in "${!args[@]}" ; do
      echo "    $arg: ${args[$arg]}"
done)
EOF

if ((! waitOnly)) ; then
    while : ; do
	newGeneration=$(oc get mcp worker -ojsonpath='{.status.observedGeneration}')
	if ((newGeneration != oldGeneration)) ; then break; fi
	sleep 1
    done
fi

declare -i start
declare -i readycount=0

start=$(tsec)

while : ; do
    # shellcheck disable=SC2034
    IFS='|' read -r name generation status count degradedcount readycount unavailable updatedcount < <(get_machine_status)
    if [[ ${status,,} = *'degraded' ]] ; then
	echo "Machine config is degraded!"
	exit 1
    fi
    echo -en "\r($(ptime "$start")) Waiting for nodes to become ready ($readycount / $count)..."
    if [[ ${status,,} = updated ]] ; then
	echo 'ready!'
	break
    fi
    sleep 10
done
exit 0