Script to safely de-register jenkins nodes usage: $ remove-nodes-safely.sh my-node-1 my-node-2 my-node-3

remove-nodes-safely.sh

#!/bin/bash
set -e
set -u

CI_MASTER_URL="http://ci-1"

node_online() {
    curl --silent "$CI_MASTER_URL/computer/$1/api/json" | grep --silent '"temporarilyOffline":false'
}

node_busy() {
    curl --silent "$CI_MASTER_URL/computer/$1/api/json" | grep --silent '"idle":false'
}

toggle_node_online() {
    curl --silent "$CI_MASTER_URL/computer/$1/toggleOffline" --request 'POST' --data 'offlineMessage=Pending node re-image'
}

deregister_node() {
    curl --silent "$CI_MASTER_URL/computer/$1/doDelete" --request 'POST' --data ''
}

wait_for_node() {
    while node_busy $1; do
        sleep 20
        echo -n "."
    done
    echo ""
}

# Mark nodes offline
for NODE in "$@"
do
    if node_online $NODE; then
        echo "Marking node $NODE as offline"
        toggle_node_online $NODE
    else
        echo "Node $NODE is already offline"
    fi
done

# Wait for nodes to finish current workload
for NODE in "$@"
do
    if node_busy $NODE; then
        echo "Waiting for node $NODE to finish its current work"
        wait_for_node $NODE
        echo "Node $NODE has finished its work"
    else
        echo "Node $NODE is not busy"
    fi
done

# De-register nodes
for NODE in "$@"
do
    echo "Permanently removing $NODE from Jenkins"
    deregister_node $NODE
done