Getting performance statistics

The following code snippet provides a reference for authenticating a user session, getting a list of the statistics files, and downloading a statistics file for individual calculations. The example code is also used in later sections to perform the actual calculations for various types of metrics that can be pulled from the system.

import re
import xml.etree.ElementTree as ET
import requests
import json
import pprint
 
def get_token(url, username, password):
    response = requests.post(
        url + "/auth", 
        headers={"X-Auth-Username": username, "X-Auth-Password": password}, 
        verify=False)
    return response.json()['token']
 
def get_namespace(element):
    m = re.match(r'\{.*\}', element.tag)
    return m.group(0) if m else ''
 
def get_directory_listing(url, token):
    response = requests.post(
        url + "/lsdumps", 
        json={"prefix": "/dumps/iostats"}, 
        headers={"X-Auth-Token": token}, 
        verify=False)
    if response.status_code != 200:
        raise Exception("Invalid directory listing") 
    return response.json()
 
def get_file_contents(url, token, filename):
    response = requests.post(
        url + "/download", 
        json={"prefix": "/dumps/iostats", "filename": filename}, 
        headers={"X-Auth-Token": token}, 
        verify=False)
    if response.status_code != 200:
        raise Exception("File not found") 
    return response.content
    
def get_latest_stats(url, username, password):
    token = get_token(url, username, password)
    files = [row['filename'] for row in get_directory_listing(url, token)]
    nm_files = [name for name in files if re.match("Nm_stats", name)]
    nv_files = [name for name in files if re.match("Nv_stats", name)]
    ng_files = [name for name in files if re.match("Ng_stats", name)]
    nn_files = [name for name in files if re.match("Nn_stats", name)]
    nd_files = [name for name in files if re.match("Nd_stats", name)]
    
    nm_xml = ET.fromstring(get_file_contents(url, token, nm_files[0]))
    nv_xml = ET.fromstring(get_file_contents(url, token, nv_files[0]))
    ng_xml = ET.fromstring(get_file_contents(url, token, ng_files[0]))
    nn_xml = ET.fromstring(get_file_contents(url, token, nn_files[0]))
    nd_xml = ET.fromstring(get_file_contents(url, token, nd_files[0]))
 
    xml = {
        "Nm_stats": nm_xml,
        "Nv_stats": nv_xml,
        "Ng_stats": ng_xml,
        "Nn_stats": nn_xml,
        "Nd_stats": nd_xml
    }
    return xml
 
def populate_fields(xml, fields):
    for item in fields.items():
        item[1]['value'] = int(
            xml[item[1]['filename']].
            find(get_namespace(xml[item[1]['filename']]) + item[1]['element']).
            attrib[item[1]['field']]
        )