# Metrics Stack Deployment Guide

Complete guide to deploying the monitoring stack (VictoriaMetrics, Grafana, node_exporter) on rick-infra.

## Overview

The metrics stack provides:
- **System monitoring**: CPU, memory, disk, network via node_exporter
- **Time-series storage**: VictoriaMetrics (Prometheus-compatible, 7x less RAM)
- **Visualization**: Grafana with Authentik SSO integration
- **Access**: `https://metrics.jnss.me` with role-based permissions

## Architecture

```
User → metrics.jnss.me (HTTPS)
  ↓
Caddy (Reverse Proxy)
  ↓
Grafana (OAuth → Authentik for SSO)
  ↓
VictoriaMetrics (Time-series DB)
  ↑
node_exporter (System Metrics)
```

All services run on localhost only, following rick-infra security principles.

## Prerequisites

### 1. Caddy Deployed
```bash
ansible-playbook rick-infra.yml --tags caddy
```

### 2. Authentik Deployed
```bash
ansible-playbook rick-infra.yml --tags authentik
```

### 3. DNS Configuration
Ensure `metrics.jnss.me` points to arch-vps IP:
```bash
dig metrics.jnss.me  # Should return 69.62.119.31
```

## Step 1: Configure Authentik OAuth Provider

### Create OAuth2/OIDC Provider

1. Login to Authentik at `https://auth.jnss.me`

2. Navigate to **Applications → Providers** → **Create**

3. Configure provider:
   - **Name**: `Grafana`
   - **Type**: `OAuth2/OpenID Provider`
   - **Authentication flow**: `default-authentication-flow`
   - **Authorization flow**: `default-provider-authorization-explicit-consent`
   - **Client type**: `Confidential`
   - **Client ID**: `grafana`
   - **Client Secret**: Click **Generate** and **copy the secret**
   - **Redirect URIs**: `https://metrics.jnss.me/login/generic_oauth`
   - **Signing Key**: Select auto-generated key
   - **Scopes**: `openid`, `profile`, `email`, `groups`

4. Click **Finish**

### Create Application

1. Navigate to **Applications** → **Create**

2. Configure application:
   - **Name**: `Grafana`
   - **Slug**: `grafana`
   - **Provider**: Select `Grafana` provider created above
   - **Launch URL**: `https://metrics.jnss.me`

3. Click **Create**

### Create Groups (Optional)

For role-based access control:

1. Navigate to **Directory → Groups** → **Create**

2. Create groups:
   - **grafana-admins**: Full admin access to Grafana
   - **grafana-editors**: Can create/edit dashboards
   - All other users get Viewer access

3. Add users to groups as needed

## Step 2: Configure Vault Variables

Edit vault file:
```bash
ansible-vault edit host_vars/arch-vps/vault.yml
```

Add these variables:
```yaml
# Grafana admin password (for emergency local login)
vault_grafana_admin_password: "your-secure-admin-password"

# Grafana secret key (generate with: openssl rand -base64 32)
vault_grafana_secret_key: "your-random-32-char-secret-key"

# OAuth credentials from Authentik
vault_grafana_oauth_client_id: "grafana"
vault_grafana_oauth_client_secret: "paste-secret-from-authentik-here"
```

Save and close (`:wq` in vim).

## Step 3: Deploy Metrics Stack

Deploy all components:
```bash
ansible-playbook rick-infra.yml --tags metrics
```

This will:
1. Install and configure VictoriaMetrics
2. Install and configure node_exporter
3. Install and configure Grafana with OAuth
4. Deploy Caddy configuration for `metrics.jnss.me`

Expected output:
```
PLAY RECAP *******************************************************
arch-vps : ok=25 changed=15 unreachable=0 failed=0 skipped=0
```

## Step 4: Verify Deployment

### Check Services

SSH to arch-vps and verify services:
```bash
# Check all services are running
systemctl status victoriametrics grafana node_exporter

# Check service health
curl http://127.0.0.1:8428/health   # VictoriaMetrics
curl http://127.0.0.1:9100/metrics  # node_exporter
curl http://127.0.0.1:3000/api/health  # Grafana
```

### Check HTTPS Access

```bash
curl -I https://metrics.jnss.me
# Should return 200 or 302 (redirect to Authentik)
```

### Check Metrics Collection

```bash
# Check VictoriaMetrics scrape targets
curl http://127.0.0.1:8428/api/v1/targets

# Should show node_exporter as "up"
```

## Step 5: Access Grafana

1. Navigate to `https://metrics.jnss.me`
2. Click **"Sign in with Authentik"**
3. Login with your Authentik credentials
4. You should be redirected to Grafana dashboard

First login will:
- Auto-create your Grafana user
- Assign role based on Authentik group membership
- Grant access to default organization

## Step 6: Verify Data Source

1. In Grafana, navigate to **Connections → Data sources**
2. Verify **VictoriaMetrics** is listed and default
3. Click on VictoriaMetrics → **Save & test**
4. Should show green "Data source is working" message

## Step 7: Create First Dashboard

### Option 1: Import Community Dashboard (Recommended)

1. Navigate to **Dashboards → Import**
2. Enter dashboard ID: `1860` (Node Exporter Full)
3. Click **Load**
4. Select **VictoriaMetrics** as data source
5. Click **Import**

You now have a comprehensive system monitoring dashboard!

### Option 2: Create Custom Dashboard

1. Navigate to **Dashboards → New → New Dashboard**
2. Click **Add visualization**
3. Select **VictoriaMetrics** data source
4. Enter PromQL query:
   ```promql
   # CPU usage
   100 - (avg by (instance) (irate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)
   ```
5. Click **Apply**

## Step 8: Configure Alerting (Optional)

Grafana supports alerting on metrics. Configure via **Alerting → Alert rules**.

Example alert for high CPU:
```promql
avg by (instance) (irate(node_cpu_seconds_total{mode="idle"}[5m])) * 100 < 20
```

## Troubleshooting

### OAuth Login Fails

**Symptom**: Redirect to Authentik, but returns error after login

**Solution**:
1. Verify redirect URI in Authentik matches exactly: `https://metrics.jnss.me/login/generic_oauth`
2. Check Grafana logs: `journalctl -u grafana -f`
3. Verify OAuth credentials in vault match Authentik

### No Metrics in Grafana

**Symptom**: Data source working, but no data in dashboards

**Solution**:
1. Check VictoriaMetrics targets: `curl http://127.0.0.1:8428/api/v1/targets`
2. Verify node_exporter is up: `systemctl status node_exporter`
3. Check time range in Grafana (top right) - try "Last 5 minutes"

### Can't Access metrics.jnss.me

**Symptom**: Connection timeout or SSL error

**Solution**:
1. Verify DNS: `dig metrics.jnss.me`
2. Check Caddy is running: `systemctl status caddy`
3. Check Caddy logs: `journalctl -u caddy -f`
4. Verify Caddy config loaded: `ls /etc/caddy/sites/grafana.caddy`

### Wrong Grafana Role

**Symptom**: User has wrong permissions (e.g., Viewer instead of Admin)

**Solution**:
1. Verify user is in correct Authentik group (`grafana-admins` or `grafana-editors`)
2. Logout of Grafana and login again
3. Check role mapping expression in `roles/metrics/defaults/main.yml`:
   ```yaml
   grafana_oauth_role_attribute_path: "contains(groups, 'grafana-admins') && 'Admin' || contains(groups, 'grafana-editors') && 'Editor' || 'Viewer'"
   ```

## Next Steps

### Add More Hosts

To monitor additional hosts (e.g., mini-vps):

1. Deploy node_exporter to target host
2. Update VictoriaMetrics scrape config to include remote targets
3. Configure remote_write or federation

### Add Service Metrics

To monitor containerized services:

1. Expose `/metrics` endpoint in application (port 8080)
2. Add scrape config in `roles/metrics/templates/scrape.yml.j2`:
   ```yaml
   - job_name: 'myservice'
     static_configs:
       - targets: ['127.0.0.1:8080']
   ```
3. Redeploy metrics role

### Set Up Alerting

1. Configure notification channels in Grafana (Email, Slack, etc.)
2. Create alert rules for critical metrics
3. Set up on-call rotation if needed

## Security Notes

- All metrics services run on localhost only
- Grafana is the only internet-facing component (via Caddy HTTPS)
- OAuth provides SSO with Authentik (no separate Grafana passwords)
- systemd hardening enabled on all services
- Default admin account should only be used for emergencies

## Resources

- **VictoriaMetrics Docs**: https://docs.victoriametrics.com/
- **Grafana Docs**: https://grafana.com/docs/
- **PromQL Guide**: https://prometheus.io/docs/prometheus/latest/querying/basics/
- **Dashboard Library**: https://grafana.com/grafana/dashboards/
- **Authentik OAuth**: https://goauthentik.io/docs/providers/oauth2/

## Support

For issues specific to rick-infra metrics deployment:
1. Check service logs: `journalctl -u <service> -f`
2. Review role README: `roles/metrics/README.md`
3. Verify vault variables are correctly set
4. Ensure Authentik OAuth provider is properly configured