---
title: "Technical report: Northwind Logistics internal panel inaccessible after automatic update"
description: "Complete structured technical report about the Northwind Logistics internal panel incident that became inaccessible after an automatic Ubuntu server update."
date: 2026-05-15
status: draft
owner: Northwind Logistics technical team
category: incident-response
severity: high
priority: urgent
tags: [docker, traefik, nodejs, ubuntu, reverse-proxy, incident, northwind-logistics, troubleshooting]
---

# Technical report: Northwind Logistics internal panel inaccessible after automatic update

## Technical summary

Following an unplanned automatic update (`unattended-upgrades`) executed at 03:00 UTC on May 15, 2026, the Northwind Logistics internal fleet management panel became inaccessible to all users. Docker containers continue to show `up` status, but HTTPS traffic isn't reaching the Node.js application correctly. This is classified as a **high severity** incident as it affects the entire company's daily operations.

**Incident date:** 2026-05-15
**Detection time:** 08:15 UTC
**Automatic update time:** 03:00 UTC
**Impact:** All internal panel users (approx. 120 employees)
**Current status:** Under diagnosis

---

## Context

### Company
Northwind Logistics is a logistics and fleet management company that operates an internal management platform for its employees. The panel allows querying fleet data, managing routes, generating reports, and coordinating daily operations.

### Technical platform

| Component | Version / Detail | Purpose |
|---|---|---|
| **OS** | Ubuntu Server 22.04 LTS | Server base |
| **Docker Engine** | 24.x | Container orchestration |
| **Docker Compose** | 2.x | Service management |
| **Traefik** | v2.10 | Reverse proxy and load balancer |
| **PostgreSQL** | 15 | Main database |
| **Redis** | 7 | Cache and sessions |
| **Node.js** | 18.x | Internal panel application |
| **n8n** | Latest stable | Process automation and reports |
| **Firewall** | UFW | Network access control |
| **TLS** | Let's Encrypt (ACME) | HTTPS certificates |

### General architecture

```
┌─────────────────────────────────────────────────────────────────┐
│                          USERS                                  │
│               (Northwind Logistics employees)                   │
└──────────────────────┬──────────────────────────────────────────┘
                       │ HTTPS
                       ↓
┌─────────────────────────────────────────────────────────────────┐
│                     FIREWALL (UFW)                              │
│              Ports 80 and 443 allowed                           │
└──────────────────────┬──────────────────────────────────────────┘
                       │
                       ↓
┌─────────────────────────────────────────────────────────────────┐
│                    TRAEFIK v2.10                                │
│         Reverse Proxy + TLS (Let's Encrypt ACME)                │
│         Manages routes: panel.northwindlogistics.internal       │
└──────────────────────┬──────────────────────────────────────────┘
                       │ Internal HTTP (port 3000)
                       ↓
┌─────────────────────────────────────────────────────────────────┐
│           DOCKER NETWORK: frontend / backend / database         │
└──────────────────────┬──────────────────────────────────────────┘
                       │
          ┌────────────┼────────────┐
          ↓            ↓            ↓
   ┌──────────┐  ┌──────────┐  ┌──────────┐
   │  Node.js │  │PostgreSQL│  │  Redis   │
   │  (app)   │  │   (db)   │  │  (cache) │
   │ :3000    │  │  :5432   │  │  :6379   │
   └──────────┘  └──────────┘  └──────────┘
          │
          ↓
┌─────────────────────────────────────────────────────────────────┐
│                      n8n                                        │
│         Automation: daily reports, alerts,                      │
│         data synchronization                                    │
└─────────────────────────────────────────────────────────────────┘
```

### Normal technical flow

1. User accesses `https://panel.northwindlogistics.internal`
2. Ubuntu firewall allows traffic on ports 80 and 443
3. Traefik receives the HTTPS connection and verifies the TLS certificate (Let's Encrypt)
4. Traefik routes the request to the Node.js application container (internal port 3000) through the Docker network
5. The Node.js application queries PostgreSQL for authentication and data retrieval
6. Redis is used for cached sessions and rate limiting
7. n8n runs periodically (via cron/container) to generate reports and send alerts

---

## Incident classification

| Field | Value |
|---|---|
| **Category** | Service availability incident |
| **Severity** | **High** — affects the entire company's operations |
| **Priority** | Urgent |
| **Status** | Under diagnosis |
| **Owner** | Technical team |
| **Scope** | All internal panel users (~120 employees) |
| **Estimated duration** | Unknown |

---

## Assumptions

1. The server remains accessible via SSH (confirmed during initial detection).
2. Docker containers appear as `up` in `docker ps` (apparently normal state).
3. The automatic update (`unattended-upgrades`) was the root cause of the incident.
4. No recent manual changes have been made to the configuration.
5. Docker's internal DNS was working correctly before the update.

---

## Related architecture and flow

### Technology stack

- **Ubuntu Server 22.04 LTS**: Base operating system with `unattended-upgrades` enabled for automatic security updates.
- **Docker Engine + Docker Compose**: Container orchestration for all services.
- **Traefik v2.10**: Reverse proxy managing incoming HTTPS traffic, automatic TLS certificates with Let's Encrypt via ACME, and rule-based routing (Docker provider).
- **PostgreSQL 15**: Relational database for the Node.js application.
- **Redis 7**: Cache engine for sessions and rate limiting.
- **Node.js 18**: Internal fleet management panel application.
- **n8n**: Automation platform for internal flows (reports, alerts, synchronization).
- **Custom Docker networks**: `northwind_frontend`, `northwind_backend`, `northwind_database`.
- **UFW**: Ubuntu firewall with specific rules for ports 80 and 443.
- **Cron jobs**: Automatic backups and maintenance tasks.

### Incident flow diagram

```
User → HTTPS (443) → UFW → Traefik → [FAILURE HERE] → Node.js (3000)
                                                      ↓
                                            PostgreSQL (5432) + Redis (6379)
                                                      ↓
                                            n8n (automation)
```

---

## Relevant configuration

### docker-compose.yml (general structure)

```yaml
version: '3.8'
services:
  traefik:
    image: traefik:v2.10
    ports:
      - "80:80"
      - "443:443"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - ./traefik.yml:/etc/traefik/traefik.yml:ro
      - ./acme.json:/acme.json
    networks:
      - frontend
      - backend
    restart: always

  app-node:
    image: node:18-alpine
    ports:
      - "3000:3000"
    volumes:
      - ./app:/app
    networks:
      - backend
      - frontend
    depends_on:
      - postgres
      - redis
    restart: always

  postgres:
    image: postgres:15-alpine
    environment:
      POSTGRES_DB: northwind
      POSTGRES_USER: admin
      POSTGRES_PASSWORD: <redacted>
    volumes:
      - pgdata:/var/lib/postgresql/data
    networks:
      - database
    restart: always

  redis:
    image: redis:7-alpine
    volumes:
      - redisdata:/data
    networks:
      - database
      - backend
    restart: always

  n8n:
    image: docker.n8n.io/n8nio/n8n
    ports:
      - "5678:5678"
    volumes:
      - n8ndata:/home/node/.n8n
    networks:
      - backend
    restart: always

networks:
  frontend:
  backend:
  database:

volumes:
  pgdata:
  redisdata:
  n8ndata:
```

### Traefik dynamic configuration (routes)

```yaml
http:
  routers:
    panel-router:
      rule: "Host(`panel.northwindlogistics.internal`)"
      service: panel-service
      entryPoints:
        - websecure
      tls:
        certResolver: letsencrypt

  services:
    panel-service:
      loadBalancer:
        servers:
          - url: "http://app-node:3000"
```

### UFW (firewall)

```
Status: active

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW IN    Anywhere
80/tcp                     ALLOW IN    Anywhere
443/tcp                    ALLOW IN    Anywhere
22/tcp (v6)                ALLOW IN    Anywhere (v6)
80/tcp (v6)                ALLOW IN    Anywhere (v6)
443/tcp (v6)               ALLOW IN    Anywhere (v6)
```

---

## Problem hypotheses

| # | Hypothesis | Likelihood | Affected area | How to verify |
|---|---|---|---|---|
| 1 | **Traefik update** that broke the configuration or routing rules | High | Reverse proxy | Check Traefik logs and installed version |
| 2 | **Node.js update** that broke application compatibility | Medium | Application | Check app logs and Node version |
| 3 | **UFW/firewall rule change** that blocked ports 80/443 | Medium | Network/Firewall | `ufw status verbose` |
| 4 | **TLS certificate exhaustion or renewal error** | Medium | TLS/ACME | Check certificates in acme.json |
| 5 | **Docker network change** preventing inter-container communication | Medium | Docker network | `docker network inspect` |
| 6 | **Node.js application port changed** after the update | Low | Application | `ss -tlnp` and docker inspect |
| 7 | **Docker internal DNS issue** not resolving service names | Low | Docker network | `docker exec traefik nslookup app-node` |
| 8 | **PostgreSQL or Redis configuration changes** preventing connection | Low | Database | Container logs |

---

## Diagnostic plan (step-by-step troubleshooting)

### Step 1: Check container status

Confirm all containers are truly operational, not just showing "up":

```bash
docker ps -a
docker compose ps
docker inspect --format='{{.State.Health.Status}}' app-node 2>/dev/null || echo "No healthcheck defined"
```

**What to look for:**
- All containers with `running` and `healthy` status
- Ports mapped correctly
- No containers in `restarting` or `unhealthy` state

### Step 2: Check Traefik logs

```bash
docker logs traefik --tail 200
docker compose logs traefik --tail 200
```

**What to look for:**
- Backend connection errors (`app-node:3000`)
- TLS certificate errors
- Incorrect routing messages
- Configuration changes detected

### Step 3: Check Node.js application logs

```bash
docker logs app-node --tail 200
docker compose logs app-node --tail 200
```

**What to look for:**
- Startup errors or crashes
- PostgreSQL or Redis connection errors
- Port changes
- Dependency errors

### Step 4: Check Traefik rules (internal API)

```bash
curl -s http://localhost:8080/api/http/routers | jq .
curl -s http://localhost:8080/api/http/services | jq .
curl -s http://localhost:8080/api/https/certificates | jq .
```

**What to look for:**
- The `panel-router` router exists and points to `app-node:3000`
- The `panel-service` service is configured correctly
- TLS certificates are valid

### Step 5: Check UFW firewall

```bash
ufw status verbose
iptables -L -n -v | grep -E ':(80|443) '
```

**What to look for:**
- Ports 80 and 443 allowed
- No new rules blocking traffic
- No changes to default policies

### Step 6: Check listening ports on the host

```bash
ss -tlnp | grep -E ':(80|443|3000|5432|6379) '
netstat -tlnp | grep -E ':(80|443|3000|5432|6379) '
```

**What to look for:**
- Traefik listening on 80 and 443
- Node.js listening on 3000 (if mapped)
- PostgreSQL on 5432 and Redis on 6379 (if exposed)

### Step 7: Check Docker networks

```bash
docker network ls
docker network inspect northwind_backend
docker network inspect northwind_frontend
docker network inspect northwind_database
```

**What to look for:**
- All networks exist and are active
- Containers are connected to the correct networks
- No network conflicts

### Step 8: Check TLS certificates

```bash
docker exec traefik ls -la /etc/traefik/acme.json 2>/dev/null || docker exec traefik ls -la /acme.json
openssl s_client -connect panel.northwindlogistics.internal:443 -servername panel.northwindlogistics.internal < /dev/null 2>/dev/null | openssl x509 -noout -dates
```

**What to look for:**
- The `acme.json` file exists and has valid content
- The certificate isn't expired
- The certificate is valid for `panel.northwindlogistics.internal`

### Step 9: Check package updates

```bash
grep -i "upgrade" /var/log/unattended-upgrades/unattended-upgrades.log
grep -i "upgrade" /var/log/dpkg.log | tail -50
dpkg -l | grep -E 'traefik|docker|nodejs|nginx'
apt list --upgradable
```

**What to look for:**
- Packages updated at 03:00 UTC
- Versions before and after the update
- Packages that could affect service operation

### Step 10: Check Docker Compose configuration

```bash
docker compose config
cat docker-compose.yml
```

**What to look for:**
- Configuration intact and correct
- No unauthorized changes
- Ports and networks configured correctly

---

## Useful diagnostic commands

### Network diagnostics

```bash
# Monitor network traffic in real time
tcpdump -i any port 80 or port 443 -w /tmp/traefik.pcap

# Check Traefik's internal connection to Node.js
docker exec traefik wget -qO- --timeout=5 http://app-node:3000/health || echo "FAILED internal connection"

# Test connection from host to Node.js
curl -v http://localhost:3000/health || echo "FAILED connection from host"

# Check internal DNS resolution
docker exec traefik nslookup app-node
docker exec traefik nslookup postgres
docker exec traefik nslookup redis
```

### Container diagnostics

```bash
# Check detailed status of each container
docker inspect app-node --format='{{json .State}}' | jq .
docker inspect postgres --format='{{json .State}}' | jq .
docker inspect redis --format='{{json .State}}' | jq .

# Check resource usage
docker stats --no-stream
docker system df
```

### System diagnostics

```bash
# System logs during the incident window
journalctl -u docker --since "2026-05-15 03:00" --until "2026-05-15 09:00"
journalctl -u ufw --since "2026-05-15 03:00" --until "2026-05-15 09:00"
journalctl -u traefik --since "2026-05-15 03:00" --until "2026-05-15 09:00"

# Check disk space
df -h
du -sh /var/lib/docker/*

# Check memory
free -h
```

---

## Resolution plan (corrective actions)

### Scenario 1: Traefik issue (most likely)

**Symptom:** Traefik isn't routing correctly to the backend.

**Actions:**
1. Check the Traefik version after the update:
   ```bash
   docker inspect traefik --format='{{.Config.Image}}'
   ```
2. If the version changed, review the changelog between versions.
3. Fix the configuration if needed (routing rules, entrypoints).
4. Restart the container:
   ```bash
   docker compose restart traefik
   ```
5. Verify routing works:
   ```bash
   curl -sk https://panel.northwindlogistics.internal/health
   ```

### Scenario 2: Node.js issue

**Symptom:** The Node.js application won't start or its port changed.

**Actions:**
1. Check logs:
   ```bash
   docker logs app-node --tail 50
   ```
2. If Node.js was updated and there's an incompatibility, roll back the version:
   ```bash
   docker compose down app-node
   docker pull node:18.19.0-alpine  # or previously known good version
   docker compose up -d app-node
   ```
3. Verify the application is listening on the correct port:
   ```bash
   docker exec app-node netstat -tlnp | grep 3000
   ```

### Scenario 3: UFW firewall issue

**Symptom:** Ports 80/443 blocked after the update.

**Actions:**
1. Check rules:
   ```bash
   ufw status verbose
   ```
2. If rules are incorrect, revert:
   ```bash
   ufw allow 80/tcp
   ufw allow 443/tcp
   ufw reload
   ```

### Scenario 4: TLS certificate issue

**Symptom:** Expired certificate or renewal error.

**Actions:**
1. Check certificate status:
   ```bash
   openssl s_client -connect panel.northwindlogistics.internal:443 < /dev/null 2>/dev/null | openssl x509 -noout -dates
   ```
2. Force renewal:
   ```bash
   docker exec traefik traefik certificates
   ```
3. If needed, restart Traefik:
   ```bash
   docker compose restart traefik
   ```

### Scenario 5: Docker network issue

**Symptom:** Containers can't communicate with each other.

**Actions:**
1. Reconnect containers to the network:
   ```bash
   docker network connect northwind_backend app-node
   docker network connect northwind_frontend app-node
   ```
2. Check DNS:
   ```bash
   docker exec app-node nslookup traefik
   docker exec app-node nslookup postgres
   ```

---

## Post-resolution validation

### Validation checklist

- [ ] The web panel is accessible from a browser (`https://panel.northwindlogistics.internal`)
- [ ] Authentication works correctly
- [ ] Data loads without errors
- [ ] Traefik routes correctly (clean logs, no errors)
- [ ] TLS certificates are valid
- [ ] UFW allows traffic on ports 80 and 443
- [ ] The Node.js application connects to PostgreSQL and Redis
- [ ] n8n executes its flows correctly
- [ ] Logs across all services are clean (no errors)
- [ ] Monitoring (if in place) reports everything as healthy
- [ ] Users are notified that the service has been restored

### Linux validations

- [ ] SSH service works (remote access possible)
- [ ] Ports 80 and 443 are listening on the host (`ss -tlnp`)
- [ ] UFW allows traffic on ports 80 and 443
- [ ] Disk space is sufficient (`df -h`)
- [ ] Memory is adequate (`free -h`)
- [ ] No zombie or abnormal processes

### Docker validations

- [ ] All containers are `running` and `healthy`
- [ ] Docker networks are configured correctly
- [ ] Ports are mapped as expected
- [ ] Volumes are mounted correctly
- [ ] Health checks are working

### Network validations

- [ ] Traefik can connect to the Node.js application internally
- [ ] The Node.js application can connect to PostgreSQL and Redis
- [ ] Docker's internal DNS resolves service names correctly
- [ ] No firewall rules blocking inter-container traffic

---

## Summary of possible solutions

| Hypothesis | Solution | Priority |
|---|---|---|
| Traefik broken by update | Roll back version, fix config, restart | **High** |
| Incompatible Node.js | Roll back Node version, restart app | **High** |
| Firewall blocking ports | Revert UFW rules, ensure ports 80/443 open | **High** |
| TLS certificates expired | Force renewal, check ACME | **Medium** |
| Docker network broken | Reconnect containers, check networks | **Medium** |
| PostgreSQL/Redis issues | Check logs, restart containers, verify ports | **Medium** |
| Node.js port changed | Check docker-compose, restart app | **Low** |
| Docker DNS not resolving | Reconnect containers, check networks | **Low** |

---

## Prevention checklist

### Immediate
- [ ] Disable `unattended-upgrades` in production or configure maintenance windows
- [ ] Document the rollback process for each component
- [ ] Keep automatic configuration and data backups

### Short term
- [ ] Implement blue-green deployment or canary releases for updates
- [ ] Set up monitoring alerts (Prometheus + Grafana) for the panel
- [ ] Implement health checks in Docker Compose
- [ ] Set up centralized logging (ELK/EFK stack)

### Medium term
- [ ] Implement CI/CD with automatic rollback
- [ ] Improve incident documentation
- [ ] Run update tests in a staging environment before production

### Long term
- [ ] Evaluate migration to an orchestrator (Kubernetes)
- [ ] Implement infrastructure as code (Terraform/Ansible)
- [ ] Establish SLA/SLO and availability metrics

---

## Final recommendations

### Immediate
1. **Roll back** the automatic updates that caused the problem.
2. **Verify and fix** the root cause identified during troubleshooting.
3. **Restart affected services** in the correct order: Traefik → Node.js → PostgreSQL → Redis.
4. **Notify users** that the service has been restored.

### Short term
1. Configure **maintenance windows** for automatic updates (e.g., weekends between 02:00–04:00 UTC).
2. Implement **proactive monitoring** with alerts to catch incidents before users report them.
3. Document the **rollback procedure** for each component in the stack.

### Medium term
1. Implement **CI/CD with automatic rollback** to minimize the impact window of future updates.
2. Improve **incident documentation** using this report as a template.
3. Set up a **staging environment** identical to production to test updates before applying them.

### Long term
1. Evaluate migration to a **container orchestrator** (Kubernetes) for greater resilience.
2. Implement **infrastructure as code** (Terraform/Ansible) for reproducibility and version control.
3. Establish clear **SLA/SLO** targets and appropriate monitoring tooling.

---

## Risks and precautions

| Risk | Mitigation |
|---|---|
| Rollback may affect other services | Test in staging first, take a server snapshot |
| Data loss during the process | Verify backups before taking any action |
| New errors after the fix | Active monitoring during and after the fix |
| Impact on n8n and reports | Verify n8n flows after restoration |
| TLS certificates in production | Don't force renewal during peak hours |

---

## Next steps

1. Run the troubleshooting plan step by step (Step 1 through Step 10)
2. Identify the correct hypothesis
3. Apply the corresponding solution
4. Validate with the post-resolution checklist
5. Document the outcome in this report
6. Update the prevention checklist with lessons learned
7. Schedule a review of the automatic update policy

---

## References

- Traefik documentation: https://doc.traefik.io/traefik/
- Docker documentation: https://docs.docker.com/
- UFW documentation: https://help.ubuntu.com/community/UFW
- PostgreSQL documentation: https://www.postgresql.org/docs/
- Redis documentation: https://redis.io/docs/
- n8n documentation: https://docs.n8n.io/

---

## Technical honesty notes

- This report is based on the information provided and standard technical diagnosis practices.
- Hypotheses must be verified using the diagnostic commands and steps described above.
- The real environment was not accessed; all recommendations are hypothetical, based on the incident description.
- The rollback procedure should be tested in a staging environment before being applied in production.
- Review by a systems engineer is recommended before executing any corrective action.

---

*Report generated on 2026-05-15 by the Northwind Logistics technical team. Document in draft state, pending validation and closure.*