Complete monitoring setup with Mimir and Alerts

[Amselll]

This Pull Request completes the Monitoring Setup for MaMpf. It includes Grafana Mimir as a long-term data storage, email alerts, more metrics, and a clearer dashboard.

Mimir as Long-Term Storage

We added a new container for Grafana Mimir, which serves as the scalable, long-term storage backend for the metrics provided by Prometheus.

Alerts

We have integrated Grafana Alerting. This allows for proactive monitoring of the MaMpf infrastructure. Currently, only alerts for RAM and CPU are integrated. The test email in the contact point file will need to be replaced.

An explanation on how to add new alerts and contact email addresses can be found in the updated monitoring guide.

Below is a screenshot of the mail catcher showing what an alert email looks like (for testing the limit was set to 1%, now its 80%):

New Dashboard

The dashboard is divided into 4 sections:

1. Infrastructure and resources:
   
2. Application:
   
   
3. Trends: Some database metrics like registered users over time.
4. Puma Metrics: Some additional Puma metrics like the number of threads or workers (only available in clustered mode).

New Metrics

• Network traffic of the app container
• RAM usage in %
• Requests per second
• Requests that returned an error in the past 24 hours
• Average SQL latency
• Average latency
• Total requests per controller over the last 24 hours
• Number of logins in the past 24 hours
• Puma worker metrics
• Puma thread metrics

[Copilot]

Pull request overview

This PR completes the repo’s monitoring setup by adding a Prometheus → Mimir remote-write pipeline, Grafana provisioning (datasources/dashboards/alerting), and extending the Ruby Prometheus exporter integration to expose additional app and Puma metrics.

Changes:

• Add a dockerized monitoring stack (Prometheus, Grafana Mimir, Grafana) plus provisioning for datasources, dashboards, and alert rules/contact points.
• Extend MampfCollector with additional DB, network, and per-Puma-process metrics.
• Enable Prometheus exporter middleware + Puma/process instrumentation outside of test.

Reviewed changes

Copilot reviewed 17 out of 19 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
package.json	Fix JSON formatting/closing brace.
lib/collectors/mampf_collector.rb	Add new gauges for DB counts, network traffic, and Puma CPU/RAM per process.
docker/monitoring/prometheus.yml	Define Prometheus scrape config and remote_write to Mimir.
docker/monitoring/mimir.yml	Add a single-node filesystem-backed Mimir config.
docker/monitoring/grafana/provisioning/datasources/datasources.yml	Provision Prometheus and Mimir datasources (Mimir default).
docker/monitoring/grafana/provisioning/dashboards/dashboards.yml	Provision file-based dashboards folder.
docker/monitoring/grafana/provisioning/alerting/notification_policies.yml	Provision Grafana notification policy routing to Mailcatcher.
docker/monitoring/grafana/provisioning/alerting/contact_points.yml	Provision an email contact point (Mailcatcher).
docker/monitoring/grafana/provisioning/alerting/alert_rules.yml	Provision CPU/RAM alert rules based on Puma process metrics.
docker/monitoring/grafana/dashboards/mampf-overview.json	Add the new “MaMpf General Overview” dashboard.
docker/monitoring/docker-compose.yml	Add Prometheus/Mimir/Grafana services for monitoring.
docker/monitoring/MONITORING.md	Add instructions for using/editing monitoring dashboards and alerts.
docker/monitoring/ACTIVATE_CLUSTER_MODE.md	Document steps to test Puma clustered mode locally.
docker/development/run.sh	Start prometheus_exporter in development container.
docker/development/compose.yml	Expose exporter port and document optional WEB_CONCURRENCY for cluster testing.
config/puma.rb	Start Prometheus exporter process/Puma instrumentation hooks (non-test).
config/initializers/prometheus_exporter.rb	Enable Prometheus exporter middleware in non-test envs.
.github/workflows/tests.yml	Minor formatting tweak.
.devcontainer/devcontainer.json	Add monitoring compose file to devcontainer setup (but currently introduces JSON issues).

Comments suppressed due to low confidence (1)

.devcontainer/devcontainer.json:56

• Monitoring services expose Grafana on port 2345 (and Prometheus/Mimir on 19090/9009), but these ports are not included in forwardPorts/portsAttributes. In Codespaces/remote devcontainers this usually means the monitoring UIs won’t be reachable via forwarded ports.

    "forwardPorts": [
        3000,
        3145,
        3036,
        3037,
        1080,
        5050,
        8060,
        3004,
        5933
    ],

[codecov]

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