flask_metrics_haproxy.py

import requests
import sentry_sdk
from flask import Flask, Response, render_template
from requests.auth import HTTPBasicAuth
from sentry_sdk.integrations.flask import FlaskIntegration

from newsblur_web import settings

if settings.FLASK_SENTRY_DSN is not None:
    sentry_sdk.init(
        dsn=settings.FLASK_SENTRY_DSN,
        integrations=[FlaskIntegration()],
        traces_sample_rate=1.0,
    )

app = Flask(__name__)

if settings.DOCKERBUILD:
    pass


STATUS_MAPPING = {
    "UNK": 0,  # unknown
    "INI": 1,  # initializing
    "SOCKERR": 2,  # socket error
    "L4OK": 3,  # check passed on layer 4, no upper layers testing enabled
    "L4TOUT": 4,  # layer 1-4 timeout
    "L4CON": 5,  # layer 1-4 connection problem, for example "Connection refused" (tcp rst) or "No route to host" (icmp)
    "L6OK": 6,  # check passed on layer 6
    "L6TOUT": 7,  # layer 6 (SSL) timeout
    "L6RSP": 8,  # layer 6 invalid response - protocol error
    "L7OK": 9,  # check passed on layer 7
    "L7OKC": 10,  # check conditionally passed on layer 7, for example 404 with disable-on-404
    "L7TOUT": 11,  # layer 7 (HTTP/SMTP) timeout
    "L7RSP": 12,  # layer 7 invalid response - protocol error
    "L7STS": 13,  # layer 7 response error, for example HTTP 5xx
}


def format_state_data(label, data):
    formatted_data = {}
    for k, v in data.items():
        if v:
            formatted_data[k] = f'{label}{{servername="{k}"}} {STATUS_MAPPING[v.strip()]}'
    return formatted_data


def fetch_states():
    res = requests.get("https://newsblur.com:1936/;csv", auth=HTTPBasicAuth("gimmiestats", "StatsGiver"))

    lines = res.content.decode("utf-8").split("\n")
    header_line = lines[0].split(",")
    check_status_index = header_line.index("check_status")
    servername_index = header_line.index("svname")

    data = {}
    backends = [line.split(",") for line in lines[1:]]
    for backend_data in backends:
        if len(backend_data) <= check_status_index:
            continue
        if len(backend_data) <= servername_index:
            continue
        if backend_data[servername_index] in ["FRONTEND", "BACKEND"]:
            continue
        backend_status = backend_data[check_status_index].replace("*", "")
        data[backend_data[servername_index]] = backend_status

    return data


@app.route("/state/")
def haproxy_state():
    backends = fetch_states()

    formatted_data = format_state_data("haproxy_state", backends)
    context = {"chart_name": "haproxy_state", "chart_type": "gauge", "data": formatted_data}
    html_body = render_template("prometheus_data.html", **context)
    return Response(html_body, content_type="text/plain")


if __name__ == "__main__":
    print(" ---> Starting NewsBlur Flask Metrics server for HAProxy...")
    app.run(host="0.0.0.0", port=5569, debug=settings.DEBUG)