What is Alerta?

The alerta monitoring system is a tool used to consolidate and de-duplicate alerts from multiple sources for quick ‘at-a-glance’ visualisation. With just one system you can monitor alerts from many other monitoring tools on a single screen.

How to use this image

To use this image run either a mongo or postgres container first:

$ docker run --name alerta-db -d mongo

Then link to the database container when running the alerta-web container:

$ export DATABASE_URL=mongodb://db:27017/monitoring
$ docker run --name alerta-web -e DATABASE_URL=$DATABASE_URL --link alerta-db:db \
-d -p <port>:8080 alerta/alerta-web

The API endpoint is at:

http://<docker>:<port>/api

Browse to the alerta console at:

http://<docker>:<port>/

Environment Variables

The following environment variables are supported for configuring the alerta-web container specifically for Docker deployments:

ADMIN_PASSWORD - sets the password of all admins. Should be changed at first login. default: alerta

ADMIN_KEY - sets an admin API key.

ADMIN_KEY_MAXAGE - sets the duration of the admin key (seconds) default: 10 years

HEARTBEAT_SEVERITY - severity used to create alerts for stale heartbeats

The following environment variables are supported by the Alerta API to ease deployment more generally:

DEBUG - debug mode for increased logging. (eg. DEBUG=1)

SECRET_KEY - a unique, randomly generated sequence of ASCII characters.

DATABASE_URL - database connection URI string. Only MongoDB and Postgres allowed.

DATABASE_NAME - used to override database name in DATABASE_URL.

AUTH_REQUIRED - require users to authenticate when using web UI or alerta CLI.

AUTH_PROVIDER - authentication provider eg. basic, ldap, openid, saml2, keycloak

ADMIN_USERS - comma-separated list of logins that will be created with "admin" role.

CUSTOMER_VIEWS - enable alert views partitioned by customer. (default:False)

OAUTH2_CLIENT_ID - client ID required by OAuth2 provider

OAUTH2_CLIENT_SECRET - client secret required by OAuth2 provider

ALLOWED_EMAIL_DOMAINS - list of authorised email domains when using Google

GITHUB_URL - GitHub Enteprise URL for privately run GitHub server

ALLOWED_GITHUB_ORGS - list of authorised GitHub organisations when using GitHub

GITLAB_URL - GitLab website URL for public or privately run GitLab server

ALLOWED_GITLAB_GROUPS - list of authorised GitLab groups when using GitLab

KEYCLOAK_URL - Keycloak URL

KEYCLOAK_REALM - Keycloak realm

ALLOWED_KEYCLOAK_ROLES - Keycloak roles

CORS_ORIGINS - list of URL origins that can access the API

MAIL_FROM - valid email address from which verification emails are sent

SMTP_PASSWORD - password for MAIL_FROM email account

PLUGINS - list of plugins to enable.

Configuration Files

To set configuration settings not supported by environment variables use configuration files instead. For example:

$ docker run -v $PWD/config/alertad.conf:/app/alertad.conf \
  -v $PWD/config/config.json:/web/config.json \
  -p <port>:8080 alerta/alerta-web

For a full list of server configuration options see https://docs.alerta.io.

Plugins

All built-in and contributed plugins are installed at image build time. Only plugins listed in PLUGINS environment variabled will be enabled.

In the example below, of all the plugins installed only those listed will be enabled at container start time:

PLUGINS=remote_ip,reject,heartbeat,blackout,slack,prometheus

Custom plugins should be installed as an additional image layer.

Authentication

To make it easy to get going with Alerta on docker quickly, the default image will use Basic Auth for user logins and login will be optional.

To allow users to login using Google OAuth, go to the Google Developer Console and create a new client ID for a web application. Then set the CLIENT_ID and CLIENT_SECRET environment variables on the command line as follows:

$ export CLIENT_ID=379647311730-6tfdcopl5fodke08el52nnoj3x8mpl3.apps.googleusercontent.com
$ export CLIENT_SECRET=UpJxs02c_bx9GlI3X8MPL3-p

Now pass in the defined environment variables to the docker run command:

$ docker run --name alerta-web  -e AUTH_PROVIDER=google -e CLIENT_ID=$CLIENT_ID \
-e CLIENT_SECRET=$CLIENT_SECRET -d -p <port>:8080 alerta/alerta-web

This will allow users to login but will only make it optional. To enforce users to login you must also set the AUTH_REQUIRED environment variable to True when starting the docker image:

$ docker run --name alerta-web -e AUTH_REQUIRED=True -e ...

To restrict logins to a certain email domain set the ALLOWED_EMAIL_DOMAIN environment variable as follows:

$ docker run --name alerta-web -e ALLOWED_EMAIL_DOMAIN=example.com ...

GitHub and GitLab can also be used as the OAuth2 providers by setting the AUTH_PROVIDER environment variable to github and gitlab respectively. For more information on using GitHub, GitHub Enterprise or GitLab as th OAuth2 provider see https://docs.alerta.io

Docker Compose

Use docker-compose to create and start Alerta and Postgres with one command:

$ docker-compose up

Example Docker Compose File

version: '2.1'
services:
  web:
    image: alerta/alerta-web
    ports:
      - "8080:8080"
    depends_on:
      - db
    environment:
      - DEBUG=1  # remove this line to turn DEBUG off
      - DATABASE_URL=postgres://postgres:postgres@db:5432/monitoring
      - AUTH_REQUIRED=True
      - ADMIN_USERS=admin@alerta.io,devops@alerta.io #default password: alerta
      - ADMIN_KEY=demo-key
      - PLUGINS=reject,blackout,normalise,enhance
    restart: always
  db:
    image: postgres
    volumes:
      - ./pg-data:/var/lib/postgresql/data
    environment:
      POSTGRES_DB: monitoring
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    restart: always

Command-line Tool

A command-line tool for alerta is available. To install it run:

$ pip install alerta

Configuration file $HOME/.alerta.conf:

[DEFAULT]
endpoint = http://<docker>:<port>/api

If authentication is enabled (ie. AUTH_REQUIRED is True), then create a new API key in the Alerta console and add the key to the configuration file. For example:

[DEFAULT]
endpoint = ...
key = 4nHAAslsGjLQ9P0QxmAlKIapLTSDfEfMDSy8BT+0

Further Reading

More information about Alerta can be found at http://docs.alerta.io

License

Copyright (c) 2014-2020 Nick Satterly. Available under the MIT License.