Alertmanager Installation

This guide walks through installing Alertmanager, starting the service, and configuring Prometheus to send alerts to it. The steps assume a Linux host with wget and tar available.

Download Alertmanager

Open the Prometheus downloads page and locate the Alertmanager section to copy the direct URL for the binary you need:
- Prometheus downloads: https://prometheus.io/download/
On the Alertmanager server, download and extract the archive:

# Example: replace <url-to-alertmanager-tarball> with the copied URL
$ wget <url-to-alertmanager-tarball>
$ tar xvf alertmanager-*.tar.gz
$ cd alertmanager-*/

Inspect the extracted files:

File / Directory	Purpose
`alertmanager`	The Alertmanager executable (binary)
`alertmanager.yml`	Default configuration file (routing, receivers, etc.)
`amtool`	Command-line utility for interacting with Alertmanager
`data/`	Storage for silences, notification states, and cluster state

The image displays a download page for Prometheus, showing downloadable files for different components like Prometheus, Alertmanager, and Blackbox Exporter, with details such as version, operating system, architecture, and file size.

You can run Alertmanager from the extracted folder. By default it looks for alertmanager.yml in the current working directory and stores runtime state under data/. Use --config.file and --storage.path to override these locations.

Start Alertmanager

From the extracted directory, start Alertmanager:

$ ./alertmanager

You should see logs similar to this, indicating successful startup and the listening address:

ts=2022-10-04T20:57:44.014Z caller=cluster.go:680 level=info component=cluster msg="Waiting for gossip to settle..." interval=2s
ts=2022-10-04T20:57:44.065Z caller=coordinator.go:113 level=info component=configuration msg="Loading configuration file" file=alertmanager.yml
ts=2022-10-04T20:57:44.065Z caller=coordinator.go:126 level=info component=configuration msg="Completed loading of configuration file" file=alertmanager.yml
ts=2022-10-04T20:57:44.068Z caller=main.go:535 level=info msg="Listening address=:9093"
ts=2022-10-04T20:57:44.068Z caller=tls_config.go:195 level=info msg="TLS is disabled." http2=false
ts=2022-10-04T20:57:46.014 caller=cluster.go:705 level=info component=cluster msg="gossip not settled" polls=0 before=0 now=1 elapsed=2.000253818s
ts=2022-10-04T20:57:51.017 caller=cluster.go:697 level=info component=cluster msg="gossip settled; proceeding"

By default Alertmanager listens on port 9093. Open a browser to http://localhost:9093/ (or replace localhost with the server IP) to access the Alertmanager web UI.

If exposing Alertmanager to the public internet, secure the interface with a reverse proxy and TLS, or restrict access via firewall rules. Alertmanager can contain sensitive routing and receiver details.

Configure Prometheus to Use Alertmanager

After Alertmanager is running, add it to your Prometheus configuration under the alerting section. Below is an example prometheus.yml snippet showing how to point Prometheus to one or more Alertmanager instances:

global:
  scrape_interval: 15s
  evaluation_interval: 15s

alerting:
  alertmanagers:
    - static_configs:
        - targets:
          - alertmanager1:9093
          - alertmanager2:9093

rule_files:
  - "rules.yml"

scrape_configs:
  # ... your scrape jobs ...

Replace alertmanager1 / alertmanager2 with hostnames or IP addresses reachable from your Prometheus server.
Prometheus sends alerts to these targets via the Alertmanager API on port 9093.

Quick Troubleshooting

If logs show “gossip not settled”, this is expected for clustered Alertmanager nodes until they discover each other.
If Prometheus can’t reach Alertmanager, confirm network reachability and that Alertmanager is listening on port 9093 (ss -lntp | grep 9093).
Use amtool for local inspection and to manage silences from the command line.

References

Prometheus downloads: https://prometheus.io/download/
Alertmanager documentation: https://prometheus.io/docs/alerting/latest/alertmanager/

Introduction

Observability Fundamentals

Prometheus Fundamentals

PromQL

Dashboarding & Visualization

Application Instrumentation

Service Discovery

Push Gateway

Alerting

Monitoring Kubernetes

Conclusion

Scaling & Long Term Storage

Alertmanager Installation

Download Alertmanager

Start Alertmanager

Configure Prometheus to Use Alertmanager

Quick Troubleshooting

References

Watch Video

​Download Alertmanager

​Start Alertmanager

​Configure Prometheus to Use Alertmanager

​Quick Troubleshooting

​References

Watch Video

Download Alertmanager

Start Alertmanager

Configure Prometheus to Use Alertmanager

Quick Troubleshooting

References