15 KiB
15 KiB
🔍 Log Monitor — User Guide
Overview
The Log Monitor scans log files on a schedule, matches regex patterns, and sends alerts via Telegram, Webhooks, Microsoft Teams, or Email. It supports time-based filtering, scheduled scans (daily, hourly, continuous), and automatic attachment of full results when matches exceed a threshold.
Starting the Monitor
Option 1: Environment File
cp .env.monitor .env
node dist-server/server.js
Option 2: Inline
LOG_MODE=monitor PORT=8082 MONITOR_SCAN_INTERVAL=30000 node dist-server/server.js
Option 3: Docker
docker run -d -p 8082:8080 \
-e LOG_MODE=monitor \
-e MONITOR_SCAN_INTERVAL=30000 \
-v /var/log:/logs:ro \
logviewer
Option 4: Config File
{
"mode": "monitor",
"port": 8082,
"monitor": {
"enabled": true,
"scanIntervalMs": 30000,
"rules": []
}
}
How It Works
┌─────────────┐ ┌──────────────┐ ┌─────────────────┐
│ Log Files │────▶│ Scan Engine │────▶│ Pattern Match │
│ (sources) │ │ (interval) │ │ (regex) │
└─────────────┘ └──────────────┘ └────────┬────────┘
│
matches found?
│
┌──────────────┴──────────────┐
│ │
≤ maxLines > maxLines
│ │
┌─────▼─────┐ ┌───────▼───────┐
│ Inline │ │ Inline (N) │
│ in alert │ │ + .gz attach │
└─────┬─────┘ └───────┬───────┘
│ │
└──────────────┬──────────────┘
│
┌──────────────▼──────────────┐
│ Send Notifications │
│ Telegram │ Webhook │ Teams │
└─────────────────────────────┘
- Scan — Every N seconds (configurable), the monitor reads all source files
- Filter — Only files matching the time range are scanned (today, this week, etc.)
- Match — Each line is tested against the configured regex patterns
- Alert — If matches are found AND cooldown has expired, notifications are sent
- Attach — If matches exceed
maxLinesInMessage, full results are gzipped and attached
GUI Guide
Layout
┌─────────────────────────────────────────────────────────────┐
│ 🔍 Log Monitor 2 active rules · 3 alerts│
├──────────────┬──────────────────────────────────────────────┤
│ │ │
│ 📋 Rules │ Rule Editor / Alert Detail │
│ ┌──────────┐│ │
│ │●Root DB ││ [General] │
│ │ 2 src ││ Name: Root DB Access Detection │
│ │ 6 match ││ Enabled: Yes │
│ ├──────────┤│ │
│ │●Failed ││ [Sources] │
│ │ 1 src ││ /var/log/db-audit.log │
│ │ 4 match ││ /var/log/db-audit-*.log.gz │
│ └──────────┘│ │
│ │ [Patterns] │
│ 📊 Alerts │ root.*login │
│ ┌──────────┐│ GRANT.*PRIVILEGES │
│ │🚨 Root DB││ DROP TABLE │
│ │ 6 matches││ │
│ │ 10:30:01 ││ [Schedule] │
│ ├──────────┤│ Mode: Daily at 07:00 │
│ │🚨 Failed ││ │
│ │ 4 matches││ [Notifications] │
│ │ 10:30:01 ││ [TELEGRAM] Bot: 811... Chat: 859... │
│ └──────────┘│ [WEBHOOK] https://hooks.slack.com/... │
│ │ │
│ │ [💾 Save] [🧪 Test Now] [🗑 Delete] │
└──────────────┴──────────────────────────────────────────────┘
Creating a Rule
- Click "+ New" in the sidebar
- Fill in the fields:
- Name — descriptive name for the rule
- Sources — one file path per line (supports globs like
/var/log/*.log) - Time Range — which files to scan (today, week, month, last N hours, all)
- Patterns — one regex per line
- Match Logic — "any" (OR) or "all" (AND)
- Schedule — continuous, daily at time, or every N hours
- Max Lines — how many lines to include inline in notifications
- Cooldown — minimum time between alerts (prevents spam)
- Add notification channels
- Click "💾 Save Rule"
Testing a Rule
- Select a rule from the sidebar
- Click "🧪 Test Now"
- The rule runs immediately and shows results below the form
- This does NOT respect cooldown — always runs
Testing Notifications
- In the Notifications section, configure a channel
- Click "🧪 Test Notification"
- A test message is sent to verify the channel works
Viewing Alerts
- Alerts appear in the "📊 Recent Alerts" section of the sidebar
- Click an alert to see the full detail view with all matched lines
- Lines are color-coded: red for ERROR/FATAL, orange for WARN
Configuration Reference
Environment Variables
| Variable | Default | Description |
|---|---|---|
LOG_MODE |
both |
Set to monitor |
PORT |
8080 |
HTTP port |
MONITOR_ENABLED |
true |
Enable/disable scanning |
MONITOR_SCAN_INTERVAL |
60000 |
Scan interval in ms |
MONITOR_STORAGE_DIR |
./monitor-data |
Where to store state |
MONITOR_RULES |
[] |
JSON array of rules (see below) |
Rule Structure
{
"id": "unique-id",
"name": "Human-readable name",
"enabled": true,
"sources": ["/path/to/logs/*.log"],
"patterns": ["regex1", "regex2"],
"patternLogic": "any",
"timeRange": { "type": "week", "hours": 24 },
"schedule": { "mode": "daily", "value": "07:00", "timezone": "Europe/Berlin" },
"notifications": [
{ "type": "telegram", "botToken": "123:ABC", "chatId": "-100123" }
],
"maxLinesInMessage": 20,
"cooldownMs": 300000,
"matchCount": 0,
"lastTriggered": null
}
Time Range Options
| Type | Description | Use Case |
|---|---|---|
today |
Only files modified today | Daily reports |
week |
Files from last 7 days | Weekly audits |
month |
Files from last 30 days | Monthly reviews |
hours |
Files from last N hours | Recent activity |
all |
All files regardless of age | Full history scan |
Schedule Options
| Mode | Value | Description |
|---|---|---|
interval |
— | Runs every scan interval (continuous monitoring) |
daily |
07:00 |
Runs once per day at the specified time |
hourly |
2 |
Runs every N hours |
Notification Channels
Telegram:
{ "type": "telegram", "botToken": "123456:ABC-DEF...", "chatId": "8599028500" }
Webhook (Slack, Discord, custom):
{ "type": "webhook", "url": "https://hooks.slack.com/services/T.../B.../..." }
Microsoft Teams:
{ "type": "teams", "url": "https://outlook.office.com/webhook/..." }
Email (SMTP):
{ "type": "email", "to": "admin@company.com", "smtpHost": "smtp.gmail.com", "smtpPort": 587, "smtpUser": "alerts@company.com", "smtpPass": "app-password" }
Example Configurations
1. Real-time Root Login Detection
Scans every 10 seconds, alerts immediately via Telegram:
LOG_MODE=monitor
PORT=8082
MONITOR_SCAN_INTERVAL=10000
MONITOR_RULES=[{"id":"root-login","name":"Root Login Alert","enabled":true,"sources":["/var/log/auth.log"],"patterns":["session opened for user root","su.*root","sudo.*root"],"patternLogic":"any","timeRange":{"type":"today"},"schedule":{"mode":"interval"},"notifications":[{"type":"telegram","botToken":"YOUR_BOT_TOKEN","chatId":"YOUR_CHAT_ID"}],"maxLinesInMessage":10,"cooldownMs":60000,"matchCount":0,"lastTriggered":null}]
2. Daily DB Audit Report at 7:00 AM
Scans once per day, sends full report:
LOG_MODE=monitor
PORT=8082
MONITOR_SCAN_INTERVAL=60000
MONITOR_RULES=[{"id":"db-audit","name":"Daily DB Audit","enabled":true,"sources":["/var/log/postgresql/audit.log","/var/log/mysql/audit*.log"],"patterns":["admin.*LOGIN","GRANT","DROP","ALTER.*TABLE","CREATE USER"],"patternLogic":"any","timeRange":{"type":"today"},"schedule":{"mode":"daily","value":"07:00","timezone":"Europe/Berlin"},"notifications":[{"type":"telegram","botToken":"TOKEN","chatId":"CHAT_ID"},{"type":"webhook","url":"https://hooks.slack.com/services/..."}],"maxLinesInMessage":20,"cooldownMs":86400000,"matchCount":0,"lastTriggered":null}]
3. Error Spike Detection (every 5 minutes)
LOG_MODE=monitor
PORT=8082
MONITOR_SCAN_INTERVAL=30000
MONITOR_RULES=[{"id":"error-spike","name":"Error Spike","enabled":true,"sources":["/app/logs/production.log"],"patterns":["\\bERROR\\b","\\bFATAL\\b","Exception","panic:"],"patternLogic":"any","timeRange":{"type":"hours","hours":1},"schedule":{"mode":"hourly","value":"0.083"},"notifications":[{"type":"teams","url":"https://outlook.office.com/webhook/..."}],"maxLinesInMessage":30,"cooldownMs":300000,"matchCount":0,"lastTriggered":null}]
4. Security: Unauthorized Access Attempts
MONITOR_RULES=[{"id":"unauth","name":"Unauthorized Access","enabled":true,"sources":["/var/log/nginx/access.log","/var/log/nginx/error.log"],"patterns":["403 Forbidden","401 Unauthorized","\\.\\./\\.\\./","etc/passwd","<script>"],"patternLogic":"any","timeRange":{"type":"today"},"schedule":{"mode":"interval"},"notifications":[{"type":"telegram","botToken":"TOKEN","chatId":"CHAT"},{"type":"webhook","url":"https://siem.internal/alerts"}],"maxLinesInMessage":15,"cooldownMs":120000,"matchCount":0,"lastTriggered":null}]
5. Multiple Rules via Config File
{
"mode": "monitor",
"port": 8082,
"monitor": {
"enabled": true,
"scanIntervalMs": 30000,
"rules": [
{
"id": "root-access",
"name": "Root DB Access",
"enabled": true,
"sources": ["/var/log/db-audit.log"],
"patterns": ["root.*login", "GRANT", "DROP TABLE"],
"patternLogic": "any",
"timeRange": { "type": "today" },
"schedule": { "mode": "interval" },
"notifications": [
{ "type": "telegram", "botToken": "TOKEN", "chatId": "CHAT" }
],
"maxLinesInMessage": 20,
"cooldownMs": 300000
},
{
"id": "disk-space",
"name": "Disk Space Warning",
"enabled": true,
"sources": ["/var/log/syslog"],
"patterns": ["No space left", "disk.*9[5-9]%", "filesystem full"],
"patternLogic": "any",
"timeRange": { "type": "hours", "hours": 2 },
"schedule": { "mode": "hourly", "value": "1" },
"notifications": [
{ "type": "webhook", "url": "https://hooks.slack.com/..." }
],
"maxLinesInMessage": 5,
"cooldownMs": 3600000
}
]
}
}
API Reference
| Method | Path | Description |
|---|---|---|
| GET | /api/monitor/rules |
List all rules |
| POST | /api/monitor/rules |
Create a new rule |
| PUT | /api/monitor/rule/:id |
Update a rule |
| DELETE | /api/monitor/rule/:id |
Delete a rule |
| POST | /api/monitor/trigger/:id |
Manually trigger a rule (ignores cooldown) |
| GET | /api/monitor/results |
Get recent alert results |
| GET | /api/monitor/config |
Get monitor configuration |
| POST | /api/monitor/test-notification |
Send a test notification |
Automating Rule Creation
You can fully automate monitor setup via the API:
# Create a rule
curl -X POST http://localhost:8082/api/monitor/rules \
-H "Content-Type: application/json" \
-d '{
"name": "My Alert",
"enabled": true,
"sources": ["/var/log/app.log"],
"patterns": ["ERROR", "FATAL"],
"patternLogic": "any",
"timeRange": {"type": "today"},
"notifications": [{"type": "telegram","botToken":"...","chatId":"..."}],
"maxLinesInMessage": 20,
"cooldownMs": 300000
}'
# Trigger it manually
curl -X POST http://localhost:8082/api/monitor/trigger/my-alert
# Check results
curl http://localhost:8082/api/monitor/results
Alert Message Format
When a rule triggers, the notification message looks like:
🚨 Log Monitor Alert: Root DB Access Detection
Matches: 6 lines
Sources: /var/log/db-audit.log
Time: 2026-04-30T07:00:01.234Z
Patterns: root.*login | GRANT.*PRIVILEGES | DROP TABLE
Sample (first 5 of 6):
2026-04-30T06:30:01Z WARN [db] root login detected from 10.0.0.1
2026-04-30T06:30:05Z WARN [db] root executed: GRANT ALL PRIVILEGES
2026-04-30T06:30:06Z ERROR [db] CRITICAL: root executed: DROP TABLE audit_log
2026-04-30T07:05:35Z WARN [db] root login detected from 192.168.1.51
2026-04-30T07:05:40Z INFO [db] root executed: ALTER TABLE users
📎 Full results (6 lines) attached as .gz file.
If total matches ≤ maxLinesInMessage: all lines are included inline.
If total matches > maxLinesInMessage: first N lines inline + full results as gzipped attachment.