kube-dns-replicas-calc.py

kube-dns-replicas-calc.py

#!/usr/bin/env python3

import argparse
from math import ceil
from prettytable import PrettyTable


def resultTable(coresPerReplica, nodesPerReplica, m, M, s=10):
    pretty_table = PrettyTable()
    pretty_table.field_names = ["Node", "replicas"]

    coresPerNode = 16

    for node in range(10, 301, s):
        r1 = ceil(node * coresPerNode / coresPerReplica)
        r2 = ceil(node / nodesPerReplica)
        replicas = max(min(max(r1, r2), M), m)
        pretty_table.add_row([node, replicas])
    print(pretty_table)

    print("coresPerReplica: {0}, nodesPerReplica: {1}, "
          "min: {2}, max: {3}".format(coresPerReplica, nodesPerReplica, m, M))


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Calculator for kube_dns replicas count')
    parser.add_argument('-M', action="store", dest="max_replicas", type=int, default=120)
    parser.add_argument('-m', action="store", dest="min_replicas", type=int, default=6)
    parser.add_argument('-c', action="store", dest="cores_per_replica", type=int, default=36)
    parser.add_argument('-n', action="store", dest="nodes_per_replica", type=int, default=16)
    parser.add_argument('-s', action="store", dest="steps", type=int, default=10)

    args = parser.parse_args()

    resultTable(
        args.cores_per_replica,
        args.nodes_per_replica,
        args.min_replicas,
        args.max_replicas,
        args.steps
    )