NewsBlur/flask_metrics/flask_metrics_mongo.py

import pymongo
import sentry_sdk
from flask import Flask, Response, render_template
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:
    connection = pymongo.MongoClient(f"mongodb://{settings.MONGO_DB['host']}")
else:
    connection = pymongo.MongoClient(
        f"mongodb://{settings.MONGO_DB['username']}:{settings.MONGO_DB['password']}@{settings.SERVER_NAME}.node.consul/?authSource=admin"
    )

MONGO_HOST = settings.SERVER_NAME


@app.route("/objects/")
def objects():
    try:
        stats = connection.newsblur.command("dbstats")
    except pymongo.errors.ServerSelectionTimeoutError as e:
        return Response(f"Server selection timeout: {e}", 500)
    except pymongo.errors.OperationFailure as e:
        return Response(f"Operation failure: {e}", 500)
    except pymongo.errors.NotMasterError as e:
        return Response(f"NotMaster error: {e}", 500)
    data = dict(objects=stats["objects"])
    formatted_data = {}
    for k, v in data.items():
        formatted_data[k] = f'mongo_objects{{db="{MONGO_HOST}"}} {v}'

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


@app.route("/mongo-replset-lag/")
def repl_set_lag():
    def _get_oplog_length():
        oplog = connection.rs.command("printReplicationInfo")
        last_op = oplog.find({}, {"ts": 1}).sort([("$natural", -1)]).limit(1)[0]["ts"].time
        first_op = oplog.find({}, {"ts": 1}).sort([("$natural", 1)]).limit(1)[0]["ts"].time
        oplog_length = last_op - first_op
        return oplog_length

    def _get_max_replication_lag():
        PRIMARY_STATE = 1
        SECONDARY_STATE = 2
        status = connection.admin.command("replSetGetStatus")
        members = status["members"]
        primary_optime = None
        oldest_secondary_optime = None
        for member in members:
            member_state = member["state"]
            optime = member["optime"]
            if member_state == PRIMARY_STATE:
                primary_optime = optime["ts"].time
            elif member_state == SECONDARY_STATE:
                if not oldest_secondary_optime or optime["ts"].time < oldest_secondary_optime:
                    oldest_secondary_optime = optime["ts"].time

        if not primary_optime or not oldest_secondary_optime:
            raise Exception("Replica set is not healthy")

        return primary_optime - oldest_secondary_optime

    try:
        # no such item for Cursor instance
        oplog_length = _get_oplog_length()
        # not running with --replSet
        replication_lag = _get_max_replication_lag()
    except pymongo.errors.ServerSelectionTimeoutError as e:
        return Response(f"Server selection timeout: {e}", 500)
    except pymongo.errors.OperationFailure as e:
        return Response(f"Operation failure: {e}", 500)
    except pymongo.errors.NotMasterError as e:
        return Response(f"NotMaster error: {e}", 500)

    formatted_data = {}
    for k, v in oplog_length.items():
        formatted_data[k] = f'mongo_oplog{{type="length", db="{MONGO_HOST}"}} {v}'
    for k, v in replication_lag.items():
        formatted_data[k] = f'mongo_oplog{{type="lag", db="{MONGO_HOST}"}} {v}'

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


@app.route("/size/")
def size():
    try:
        stats = connection.newsblur.command("dbstats")
    except pymongo.errors.ServerSelectionTimeoutError as e:
        return Response(f"Server selection timeout: {e}", 500)
    except pymongo.errors.OperationFailure as e:
        return Response(f"Operation failure: {e}", 500)
    except pymongo.errors.NotMasterError as e:
        return Response(f"NotMaster error: {e}", 500)
    data = dict(size=stats["fsUsedSize"])
    formatted_data = {}
    for k, v in data.items():
        formatted_data[k] = f'mongo_db_size{{db="{MONGO_HOST}"}} {v}'

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


@app.route("/ops/")
def ops():
    try:
        status = connection.admin.command("serverStatus")
    except pymongo.errors.ServerSelectionTimeoutError as e:
        return Response(f"Server selection timeout: {e}", 500)
    except pymongo.errors.OperationFailure as e:
        return Response(f"Operation failure: {e}", 500)
    except pymongo.errors.NotMasterError as e:
        return Response(f"NotMaster error: {e}", 500)
    data = dict((q, status["opcounters"][q]) for q in status["opcounters"].keys())

    formatted_data = {}
    for k, v in data.items():
        formatted_data[k] = f'mongo_ops{{type="{k}", db="{MONGO_HOST}"}} {v}'

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


@app.route("/page-faults/")
def page_faults():
    try:
        status = connection.admin.command("serverStatus")
    except pymongo.errors.ServerSelectionTimeoutError as e:
        return Response(f"Server selection timeout: {e}", 500)
    except pymongo.errors.OperationFailure as e:
        return Response(f"Operation failure: {e}", 500)
    except pymongo.errors.NotMasterError as e:
        return Response(f"NotMaster error: {e}", 500)
    try:
        value = status["extra_info"]["page_faults"]
    except KeyError:
        value = "U"
    data = dict(page_faults=value)
    formatted_data = {}
    for k, v in data.items():
        formatted_data[k] = f'mongo_page_faults{{db="{MONGO_HOST}"}} {v}'

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


@app.route("/page-queues/")
def page_queues():
    try:
        status = connection.admin.command("serverStatus")
    except pymongo.errors.ServerSelectionTimeoutError as e:
        return Response(f"Server selection timeout: {e}", 500)
    except pymongo.errors.OperationFailure as e:
        return Response(f"Operation failure: {e}", 500)
    except pymongo.errors.NotMasterError as e:
        return Response(f"NotMaster error: {e}", 500)
    data = dict((q, status["globalLock"]["currentQueue"][q]) for q in ("readers", "writers"))
    formatted_data = {}
    for k, v in data.items():
        formatted_data[k] = f'mongo_page_queues{{type="{k}", db="{MONGO_HOST}"}} {v}'

    context = {
        "data": formatted_data,
        "chart_name": "queues",
        "chart_type": "gauge",
    }
    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...")
    app.run(host="0.0.0.0", port=5569)