Alerta is an open-source, Apache-2.0 licensed monitoring system in Python that aggregates alerts from any source into a single API-driven server and web console, and it is aimed at operations and platform teams that want a scalable, low-configuration alert aggregation layer instead of another polling-based monitoring stack.

What it is

Alerta Release 9.1 is a distributed and de-coupled monitoring tool built around a Python API server, a command-line client, and a separate web console. The project describes three aims for its design: it is scalable because its components are distributed and de-coupled, it needs minimal configuration so that it accepts alerts from any source, and it offers quick at-a-glance visualisation with drill-down to detail. Release 9 requires Python 3.9 or higher, and the only mandatory dependency is a database — either MongoDB or PostgreSQL. Everything else is optional.

The concrete problem Alerta solves is fragmented alert handling. Rather than letting every monitoring source keep its own dashboard, inbox, and retention rules, Alerta provides one HTTP API server that normalises inbound alerts from arbitrary sources and stores them in the database the operator already runs. That database is a hard requirement rather than an add-on: the installation procedure installs MongoDB first and starts the mongod daemon before the Alerta server itself. Postgres support is a first-class alternative, exercised by its own test environment.

Key capabilities

• Runs an API server and command-line client installed with pip install alerta-server alerta, started with the alertad run command.
• Persists alerts in MongoDB version 6.0 or better, or PostgreSQL version 13 or better, selected through the DATABASE_URL environment variable.
• Accepts configuration overrides in /etc/alertad.conf, or through any path named in the ALERTA_SVR_CONF_FILE environment variable.
• Ships a separately distributed web console, published as the alerta-webui.tar.gz release archive and quickly served with python3 -m http.server 8000.
• Provides a Docker path through the alerta/docker-alerta repository and the alerta/alerta-web image on Docker Hub.
• Supports verbose troubleshooting output with DEBUG=True together with LOG_HANDLERS = ['console','file'], LOG_FORMAT, and LOG_FILE.
• Reports server errors to Sentry when a SENTRY_DSN value is configured.

Who uses it and how

• Operators deploying containers can run Alerta and MongoDB together using the alerta/docker-alerta Docker setup rather than installing packages on the host.
• Teams running cloud infrastructure deploy Alerta to Heroku, AWS EC2, or Google Cloud Platform, as the README lists all three as supported targets.
• Developers working on the server itself run it in Flask development mode with FLASK_APP=alerta and FLASK_DEBUG=1, listening on port 5000, or on port 8080 with threaded requests, a live reloader, a Postgres URL, and Sentry error reporting.
• Contributors and CI pipelines exercise the full test matrix with TOXENV=ALL make test, or narrow it to TOXENV=postgres and TOXENV=mongodb, which requires a local Postgres and MongoDB instance to be running.
• Users who prefer conversational help join the project community on Slack at slack.alerta.dev.

Getting started

Install the server and client from PyPI with pip install alerta-server alerta, then start the service with alertad run against a MongoDB or PostgreSQL database that is already reachable. A container-based route exists through the alerta/docker-alerta repository if installing packages directly is not preferred.

How it compares

The provided facts do not name any similar or competing alerting tool, paid or otherwise, so no licence, hosting, or cost comparison can be drawn here. On the evidence available, Alerta stands alone in this registry: it is registered as an open-source monitoring system with no listed alternatives.

When to use it — and when not to

A self-hoster must operate at least one supported database, MongoDB 6.0 or newer or PostgreSQL 13 or newer, because it is the only mandatory dependency, and must also host the web console themselves from the release archive or a container, so this is not a purely managed experience. Anyone without Python 3.9 or higher, or without the appetite to run a database alongside an API server, should look elsewhere. The facts also carry weaknesses worth noting: the published licence text runs to 2023, the repository shows 34 open issues, and the README defers authentication, permissions, and detailed configuration to the external documentation site rather than covering them inline.

$ sudo apt-get install -y mongodb-org
$ mongod

$ sudo yum install -y mongodb
$ mongod

$ pip install alerta-server alerta
$ alertad run

$ wget https://github.com/alerta/alerta-webui/releases/latest/download/alerta-webui.tar.gz
$ tar zxvf alerta-webui.tar.gz
$ cd dist
$ python3 -m http.server 8000

>> browse to http://localhost:8000

$ ALERTA_SVR_CONF_FILE=~/.alertad.conf
$ echo "DEBUG=True" > $ALERTA_SVR_CONF_FILE

$ export FLASK_APP=alerta FLASK_DEBUG=1
$ pip install -e .
$ flask run

$ export FLASK_APP=alerta FLASK_DEBUG=1
$ export DATABASE_URL=postgres://localhost:5432/alerta5
$ export SENTRY_DSN=https://8b56098250544fb78b9578d8af2a7e13:[email protected]/153768
$ pip install -e .[postgres]
$ flask run --debugger --port 8080 --with-threads --reload

DEBUG=True

LOG_HANDLERS = ['console','file']
LOG_FORMAT = 'verbose'
LOG_FILE = '$HOME/alertad.log'

$ TOXENV=ALL make test

$ TOXENV=postgres make test
$ TOXENV=mongodb make test

$ TOXENV="mongodb -- tests/test_search.py::QueryParserTestCase::test_boolean_operators" make test
$ TOXENV="postgres -- tests/test_queryparser.py::PostgresQueryTestCase::test_boolean_operators" make test

Alerta monitoring system and console
Copyright 2012-2023 Nick Satterly

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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