Send parallel API requests to kube-api server

query-kubeapiserver.sh

#!/bin/bash -eux

# This file is based on https://code.launchpad.net/~freyes/+git/experiment
# Modified to use xargs instead of parallel

# source: https://kubernetes.io/docs/tasks/administer-cluster/access-cluster-api/

PARALLEL_REQS=20
SLEEP_SECS=0.1
TEMPLOG=$(mktemp).log
K8S_ENDPOINT='/api'

# Select name of cluster you want to interact with from above output:
export CLUSTER_NAME="juju-cluster"

# Point to the API server referring the cluster name
APISERVER=$(kubectl config view -o jsonpath="{.clusters[?(@.name==\"$CLUSTER_NAME\")].cluster.server}")

# Gets the token value
TOKEN=$(kubectl get secrets -o jsonpath="{.items[?(@.metadata.annotations['kubernetes\.io/service-account\.name']=='default')].data.token}"|base64 --decode)

# trap ctrl-c and call ctrl_c()
trap ctrl_c INT

function ctrl_c() {
  local DEST=query-kubeapiserver.$(date '+%Y%m%d_%H%M').log
  mv $TEMPLOG $DEST
  echo "output at $DEST"
  exit 0
}

set +x
while true; do
  seq $PARALLEL_REQS | xargs -I {} -n1 -P$PARALLEL_REQS curl -s -X GET $APISERVER$K8S_ENDPOINT --header "Authorization: Bearer $TOKEN" --insecure 2>&1 >> $TEMPLOG
  /bin/sleep $SLEEP_SECS
done