Prometheus 3 on Ubuntu 24.04

## Prometheus 3 on Ubuntu 24.04 by cloudimg

Prometheus 3 on Ubuntu 24.04 LTS (Noble Numbat), purpose built for Microsoft Azure and maintained by cloudimg. Prometheus is the de facto open source time series metrics server in production observability stacks, with mature support for service discovery, recording rules, alerting rules, federation, and a powerful PromQL query language. Prometheus 3 ships major improvements in PromQL evaluation, native histograms, OTLP metrics ingestion, and remote write reliability over the 2.x line.

Why Choose cloudimg?

* 24/7 Expert Support with guaranteed 24 hour response for all requests and one hour average for critical issues. Contact support@cloudimg.co.uk

* Production Ready from Launch Pre configured, security patched, and validated before publication

* Azure Native Integration Built with Azure Linux Agent, cloud init, and Gen2 Hyper V support

* Latest 3.x at Build Time The recipe resolves the latest non prerelease 3.x tag from the official Prometheus GitHub releases at build time, so each new image ships with the most current stable Prometheus 3 binary

What is Included

* Prometheus 3 server installed from the official prometheus.io GitHub release tarball (linux-amd64)

* promtool installed at /usr/local/bin/promtool for config validation, rule testing, and tsdb administration

* Console templates and console libraries at /etc/prometheus/consoles/ and /etc/prometheus/console_libraries/

* prometheus.service systemd unit auto starting on boot

* prometheus-firstboot.service systemd oneshot that writes endpoint info on first customer boot

* Default scrape config at /etc/prometheus/prometheus.yml with the prometheus job pre seeded for self monitoring; example node and Grafana scrape jobs commented in for customers to uncomment and edit

* TSDB at /var/lib/prometheus/data — NOT /mnt (Azure /mnt is the ephemeral resource disk and is not preserved through SIG capture)

* Listener on TCP 9090 (HTTP, no built in auth — terminate TLS + basic auth at a reverse proxy for production)

* Ubuntu 24.04 LTS base with latest security patches applied at build time

* Azure Linux Agent for seamless cloud integration and SSH key injection

Pairs With Grafana

Prometheus is the canonical metrics source for Grafana dashboards. Pair this image with the cloudimg `grafana-12-ubuntu-24-04` image — add Prometheus as a data source in Grafana with URL `http://:9090` and you have a complete observability stack in two VMs.

Use Cases

* Single pane metrics ingestion for a small to medium VM fleet (use node_exporter on every monitored VM)

* Application metrics scraping for any code that exposes a /metrics endpoint (every Spring Boot, Go, Python, Node.js framework supports the Prometheus text format)

* Kubernetes monitoring (federate from a kube-prometheus-stack instance)

* Azure Monitor metrics complement when you want PromQL on top of Azure native data (via the azure_monitor exporter)

* Alert routing source for Alertmanager (deploy separately) into PagerDuty, Opsgenie, Slack, Teams, email

Notes on TLS and Authentication

Prometheus 3 ships with NO built in authentication and listens on plain HTTP. This is by design — the upstream Prometheus team treats auth and TLS as concerns for an external reverse proxy. For any production deployment:

* Front Prometheus with Nginx, Caddy, Apache, or an Azure Application Gateway

* Add basic auth or AAD authentication at the proxy

* Terminate TLS at the proxy with a real cert

* The cloudimg `nginx-ssl-certbot-ubuntu-24-04` image is purpose built as a companion reverse proxy

Technical Specifications

* Operating System: Ubuntu 24.04 LTS (Noble Numbat)

* Prometheus Version: latest 3.x at build time (resolved from github.com/prometheus/prometheus/releases)

* Web UI Port: 9090

* Config: /etc/prometheus/prometheus.yml

* TSDB: /var/lib/prometheus/data

* Default User: azureuser (sudo enabled)

* Service Management: systemd (prometheus.service, prometheus-firstboot.service)

* Recommended Size: Standard_B2s for development; Standard_D2s_v3 with attached Premium SSD for production

* VM Generation: Hyper V Gen2 with UEFI boot

Support

cloudimg provides 24/7/365 expert technical support. Contact support@cloudimg.co.uk or visit www.cloudimg.co.uk for the latest documentation and deployment guides.