prometheus-alertmanager

What is prometheus-alertmanager?

The prometheus-alertmanager image runs Alertmanager, a component of the Prometheus monitoring ecosystem responsible for handling alerts sent by Prometheus servers.

Alertmanager manages deduplication, grouping, throttling, and routing of alerts to notification channels such as email, PagerDuty, Slack, Webhooks, Opsgenie, and more. It supports sophisticated silencing, inhibition, and templating to reduce alert noise and improve on-call response.

This image is commonly deployed alongside Prometheus in observability stacks, both in Kubernetes and standalone Docker environments. It’s essential for teams implementing alert-driven SRE workflows or automating incident response.

How to use this image

Alertmanager is configured using a YAML file (alertmanager.yml) and typically run as part of a Prometheus stack.

Run Alertmanager with a local config:

<code>docker run -d -p 9093:9093 \  -v $(pwd)/alertmanager.yml:/etc/alertmanager/alertmanager.yml \  prom/alertmanager</code>

Basic alertmanager.yml example:

<code>global:  resolve_timeout: 5mroute:  receiver: team-slack  group_wait: 10s  group_interval: 5m  repeat_interval: 3hreceivers:  - name: team-slack    slack_configs:      - channel: "#alerts"        send_resolved: true        api_url: "https://hooks.slack.com/services/..."inhibit_rules:  - source_match:      severity: "critical"    target_match:      severity: "warning"    equal: ["alertname", "cluster"]</code>

Ports and access:

Web UI: http://localhost:9093

Config reloads: Send SIGHUP to reload without restart.

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Image variants

Published under prom/alertmanager, the image includes minimal and versioned builds. No Alpine or slim variants exist.

prom/alertmanager:latest

Tracks the latest stable release of Alertmanager.Use for dev/testing environments.•

prom/alertmanager:<version>

Tagged by semantic version (e.g. v0.27.0, v0.25.0).

Recommended for production to avoid unintentional changes.The image is based on a minimal base and contains only the Alertmanager binary and config directory.