# RabbitMQ - Message Broker Infrastructure

## Overview

RabbitMQ 3 (management-alpine) serves as the central message broker for the Ouranos sandbox, providing AMQP-compliant message queuing for asynchronous communication between services. The deployment includes the management web interface for monitoring and administration.

**Host:** Oberon (container_orchestration)  
**Role:** Message broker for event-driven architectures  
**AMQP Port:** 5672  
**Management Port:** 25582  
**Syslog Port:** 51402 (Alloy)

## Architecture

```
┌─────────────────────────────────────────────────────────┐
│                      Oberon Host                        │
│                                                         │
│  ┌──────────────────────────────────────────────────┐  │
│  │        RabbitMQ Container (Docker)               │  │
│  │                                                  │  │
│  │  ┌──────────────┬──────────────┐                │  │
│  │  │  VHost       │  VHost       │                │  │
│  │  │  "kairos"    │  "spelunker" │                │  │
│  │  │              │              │                │  │
│  │  │  User:       │  User:       │                │  │
│  │  │  kairos      │  spelunker   │                │  │
│  │  │  (full perm) │  (full perm) │                │  │
│  │  └──────────────┴──────────────┘                │  │
│  │                                                  │  │
│  │  Default Admin: rabbitmq                        │  │
│  │  (all vhosts, admin privileges)                 │  │
│  │                                                  │  │
│  └──────────────────────────────────────────────────┘  │
│                                                         │
│  Ports: 5672 (AMQP), 25582 (Management)                │
│  Logs: syslog → Alloy:51402 → Loki                     │
└─────────────────────────────────────────────────────────┘

  ┌──────────────┐            ┌──────────────┐
  │   Kairos     │───AMQP────▶│  kairos/     │
  │  (future)    │            │  (vhost)     │
  └──────────────┘            └──────────────┘

  ┌──────────────┐            ┌──────────────┐
  │  Spelunker   │───AMQP────▶│  spelunker/  │
  │  (future)    │            │  (vhost)     │
  └──────────────┘            └──────────────┘
```

**Note**: Kairos and Spelunker are future services. The RabbitMQ infrastructure is pre-provisioned with dedicated virtual hosts and users ready for when these services are deployed.

## Terraform Resources

### Oberon Host Definition

RabbitMQ runs on Oberon, defined in `terraform/containers.tf`:

| Attribute | Value |
|-----------|-------|
| Description | Docker Host + MCP Switchboard - King of Fairies orchestrating containers |
| Image | noble |
| Role | container_orchestration |
| Security Nesting | `true` (required for Docker) |
| AppArmor Profile | unconfined |
| Proxy Devices | `25580-25599 → 25580-25599` (application port range) |

### Container Dependencies

| Resource | Relationship |
|----------|--------------|
| Docker | RabbitMQ runs as a Docker container on Oberon |
| Alloy | Collects syslog logs from RabbitMQ on port 51402 |
| Prospero | Receives logs via Loki for observability |

## Ansible Deployment

### Playbook

```bash
cd ansible
ansible-playbook rabbitmq/deploy.yml
```

### Files

| File | Purpose |
|------|---------|
| `rabbitmq/deploy.yml` | Main deployment playbook |
| `rabbitmq/docker-compose.yml.j2` | Docker Compose template |

### Deployment Steps

The playbook performs the following operations:

1. **User and Group Management**
   - Creates `rabbitmq` system user and group
   - Adds `ponos` user to `rabbitmq` group for operational access
   
2. **Directory Setup**
   - Creates service directory at `/srv/rabbitmq`
   - Sets ownership to `rabbitmq:rabbitmq`
   - Configures permissions (mode 750)

3. **Docker Compose Deployment**
   - Templates `docker-compose.yml` from Jinja2 template
   - Deploys RabbitMQ container with `docker compose up`

4. **rabbitmqadmin CLI Setup**
   - Extracts `rabbitmqadmin` from container to `/usr/local/bin/`
   - Makes it executable for host-level management

5. **Automatic Provisioning** (idempotent)
   - Creates virtual hosts: `kairos`, `spelunker`
   - Creates users with passwords from vault
   - Sets user tags (currently none, expandable for admin/monitoring roles)
   - Configures full permissions for each user on their respective vhost

### Variables

#### Host Variables (`host_vars/oberon.incus.yml`)

| Variable | Description | Default |
|----------|-------------|---------|
| `rabbitmq_user` | Service user | `rabbitmq` |
| `rabbitmq_group` | Service group | `rabbitmq` |
| `rabbitmq_directory` | Installation directory | `/srv/rabbitmq` |
| `rabbitmq_amqp_port` | AMQP protocol port | `5672` |
| `rabbitmq_management_port` | Management web interface | `25582` |
| `rabbitmq_password` | Default admin password | `{{ vault_rabbitmq_password }}` |

#### Group Variables (`group_vars/all/vars.yml`)

Defines the provisioning configuration for vhosts, users, and permissions:

```yaml
rabbitmq_vhosts:
  - name: kairos
  - name: spelunker

rabbitmq_users:
  - name: kairos
    password: "{{ kairos_rabbitmq_password }}"
    tags: []
  - name: spelunker
    password: "{{ spelunker_rabbitmq_password }}"
    tags: []

rabbitmq_permissions:
  - vhost: kairos
    user: kairos
    configure_priv: .*
    read_priv: .*
    write_priv: .*
  - vhost: spelunker
    user: spelunker
    configure_priv: .*
    read_priv: .*
    write_priv: .*
```

**Vault Variable Mappings**:
```yaml
kairos_rabbitmq_password: "{{ vault_kairos_rabbitmq_password }}"
spelunker_rabbitmq_password: "{{ vault_spelunker_rabbitmq_password }}"
```

#### Vault Variables (`group_vars/all/vault.yml`)

All sensitive credentials are encrypted in the vault:

| Variable | Description |
|----------|-------------|
| `vault_rabbitmq_password` | Default admin account password |
| `vault_kairos_rabbitmq_password` | Kairos service user password |
| `vault_spelunker_rabbitmq_password` | Spelunker service user password |

## Configuration

### Docker Compose Template

The deployment uses a minimal Docker Compose configuration:

```yaml
services:
  rabbitmq:
    image: rabbitmq:3-management-alpine
    container_name: rabbitmq
    restart: unless-stopped
    ports:
      - "{{rabbitmq_amqp_port}}:5672"      # AMQP protocol
      - "{{rabbitmq_management_port}}:15672" # Management UI
    volumes:
      - rabbitmq_data:/var/lib/rabbitmq    # Persistent data
    environment:
      RABBITMQ_DEFAULT_USER: "{{rabbitmq_user}}"
      RABBITMQ_DEFAULT_PASS: "{{rabbitmq_password}}"
    logging:
      driver: syslog
      options:
        syslog-address: "tcp://127.0.0.1:{{rabbitmq_syslog_port}}"
        syslog-format: "{{syslog_format}}"
        tag: "rabbitmq"
```

### Data Persistence

- **Volume**: `rabbitmq_data` (Docker-managed volume)
- **Location**: `/var/lib/rabbitmq` inside container
- **Contents**:
  - Message queues and persistent messages
  - Virtual host metadata
  - User credentials and permissions
  - Configuration overrides

## Virtual Hosts and Users

### Default Admin Account

**Username**: `rabbitmq`  
**Password**: `{{ vault_rabbitmq_password }}` (from vault)  
**Privileges**: Full administrative access to all virtual hosts

The default admin account is created automatically when the container starts and can access:
- All virtual hosts (including `/`, `kairos`, `spelunker`)
- Management web interface
- All RabbitMQ management commands

### Kairos Virtual Host

**VHost**: `kairos`  
**User**: `kairos`  
**Password**: `{{ vault_kairos_rabbitmq_password }}`  
**Permissions**: Full (configure, read, write) on all resources matching `.*`

Intended for the **Kairos** service (event-driven time-series processing system, planned future deployment).

### Spelunker Virtual Host

**VHost**: `spelunker`  
**User**: `spelunker`  
**Password**: `{{ vault_spelunker_rabbitmq_password }}`  
**Permissions**: Full (configure, read, write) on all resources matching `.*`

Intended for the **Spelunker** service (log exploration and analytics platform, planned future deployment).

### Permission Model

Both service users have full access within their respective virtual hosts:

| Permission | Pattern | Description |
|------------|---------|-------------|
| Configure | `.*` | Create/delete queues, exchanges, bindings |
| Write | `.*` | Publish messages to exchanges |
| Read | `.*` | Consume messages from queues |

This isolation ensures:
- ✔ Each service operates in its own namespace
- ✔ Messages cannot cross between services
- ✔ Resource limits can be applied per-vhost
- ✔ Service credentials can be rotated independently

## Access and Administration

### Management Web Interface

**URL**: `http://oberon.incus:25582`  
**External**: `http://{oberon-ip}:25582`  
**Login**: `rabbitmq` / `{{ vault_rabbitmq_password }}`

Features:
- Queue inspection and message browsing
- Exchange and binding management
- Connection and channel monitoring
- User and permission administration
- Virtual host management
- Performance metrics and charts

### CLI Administration

#### On Host Machine (using rabbitmqadmin)

```bash
# List vhosts
rabbitmqadmin -H oberon.incus -P 25582 -u rabbitmq -p PASSWORD list vhosts

# List queues in a vhost
rabbitmqadmin -H oberon.incus -P 25582 -u rabbitmq -p PASSWORD -V kairos list queues

# Publish a test message
rabbitmqadmin -H oberon.incus -P 25582 -u rabbitmq -p PASSWORD -V kairos publish \
  exchange=amq.default routing_key=test payload="test message"
```

#### Inside Container

```bash
# Enter the container
docker exec -it rabbitmq /bin/sh

# List vhosts
rabbitmqctl list_vhosts

# List users
rabbitmqctl list_users

# List permissions for a user
rabbitmqctl list_user_permissions kairos

# List queues in a vhost
rabbitmqctl list_queues -p kairos

# Check node status
rabbitmqctl status
```

### Connection Strings

#### AMQP Connection (from other containers on Oberon)

```
amqp://kairos:PASSWORD@localhost:5672/kairos
amqp://spelunker:PASSWORD@localhost:5672/spelunker
```

#### AMQP Connection (from other hosts)

```
amqp://kairos:PASSWORD@oberon.incus:5672/kairos
amqp://spelunker:PASSWORD@oberon.incus:5672/spelunker
```

#### Management API

```
http://rabbitmq:PASSWORD@oberon.incus:25582/api/
```

## Monitoring and Observability

### Logging

- **Driver**: syslog (Docker logging driver)
- **Destination**: `tcp://127.0.0.1:51402` (Alloy on Oberon)
- **Tag**: `rabbitmq`
- **Format**: `{{ syslog_format }}` (from Alloy configuration)

Logs are collected by Alloy and forwarded to Loki on Prospero for centralized log aggregation.

### Key Metrics (via Management UI)

| Metric | Description |
|--------|-------------|
| Connections | Active AMQP client connections |
| Channels | Active channels within connections |
| Queues | Total queues across all vhosts |
| Messages | Ready, unacknowledged, and total message counts |
| Message Rate | Publish/deliver rates (msg/s) |
| Memory Usage | Container memory consumption |
| Disk Usage | Persistent storage utilization |

### Health Check

```bash
# Check if RabbitMQ is running
docker ps | grep rabbitmq

# Check container logs
docker logs rabbitmq

# Check RabbitMQ node status
docker exec rabbitmq rabbitmqctl status

# Check cluster health (single-node, should show 1 node)
docker exec rabbitmq rabbitmqctl cluster_status
```

## Operational Tasks

### Restart RabbitMQ

```bash
# Via Docker Compose
cd /srv/rabbitmq
sudo -u rabbitmq docker compose restart

# Via Docker directly
docker restart rabbitmq
```

### Recreate Container (preserves data)

```bash
cd /srv/rabbitmq
sudo -u rabbitmq docker compose down
sudo -u rabbitmq docker compose up -d
```

### Add New Virtual Host and User

1. Update `group_vars/all/vars.yml`:
   ```yaml
   rabbitmq_vhosts:
     - name: newservice
   
   rabbitmq_users:
     - name: newservice
       password: "{{ newservice_rabbitmq_password }}"
       tags: []
   
   rabbitmq_permissions:
     - vhost: newservice
       user: newservice
       configure_priv: .*
       read_priv: .*
       write_priv: .*
   
   # Add mapping
   newservice_rabbitmq_password: "{{ vault_newservice_rabbitmq_password }}"
   ```

2. Add password to `group_vars/all/vault.yml`:
   ```bash
   ansible-vault edit inventory/group_vars/all/vault.yml
   # Add: vault_newservice_rabbitmq_password: "secure_password"
   ```

3. Run the playbook:
   ```bash
   ansible-playbook rabbitmq/deploy.yml
   ```

The provisioning tasks are idempotent—existing vhosts and users are skipped, only new ones are created.

### Rotate User Password

```bash
# Inside container
docker exec rabbitmq rabbitmqctl change_password kairos "new_password"

# Update vault
ansible-vault edit inventory/group_vars/all/vault.yml
# Update vault_kairos_rabbitmq_password
```

### Clear All Messages in a Queue

```bash
docker exec rabbitmq rabbitmqctl purge_queue queue_name -p kairos
```

## Troubleshooting

### Container Won't Start

Check Docker logs for errors:
```bash
docker logs rabbitmq
```

Common issues:
- Port conflict on 5672 or 25582
- Permission issues on `/srv/rabbitmq` directory
- Corrupted data volume

### Cannot Connect to Management UI

1. Verify port mapping: `docker port rabbitmq`
2. Check firewall rules on Oberon
3. Verify container is running: `docker ps | grep rabbitmq`
4. Check if management plugin is enabled (should be in `-management-alpine` image)

### User Authentication Failing

```bash
# List users and verify they exist
docker exec rabbitmq rabbitmqctl list_users

# Check user permissions
docker exec rabbitmq rabbitmqctl list_user_permissions kairos

# Verify vhost exists
docker exec rabbitmq rabbitmqctl list_vhosts
```

### High Memory Usage

RabbitMQ may consume significant memory with many messages. Check:
```bash
# Memory usage
docker exec rabbitmq rabbitmqctl status | grep memory

# Queue depths
docker exec rabbitmq rabbitmqctl list_queues -p kairos messages

# Consider setting memory limits in docker-compose.yml
```

## Security Considerations

### Network Isolation

- RabbitMQ AMQP port (5672) is **only** exposed on the Incus network (`10.10.0.0/16`)
- Management UI (25582) is exposed externally for administration
- For production: Place HAProxy in front of management UI with authentication
- Consider enabling SSL/TLS for AMQP connections in production

### Credential Management

- ✔ All passwords stored in Ansible Vault
- ✔ Service accounts have isolated virtual hosts
- ✔ Default admin account uses strong password from vault
- ⚠️ Credentials passed as environment variables (visible in `docker inspect`)
- Consider using Docker secrets or Vault integration for enhanced security

### Virtual Host Isolation

Each service operates in its own virtual host:
- Messages cannot cross between vhosts
- Resource quotas can be applied per-vhost
- Credentials can be rotated without affecting other services

## Future Enhancements

- [ ] **SSL/TLS Support**: Enable encrypted AMQP connections
- [ ] **Cluster Mode**: Add additional RabbitMQ nodes for high availability
- [ ] **Federation**: Connect to external RabbitMQ clusters
- [ ] **Prometheus Exporter**: Add metrics export for Grafana monitoring
- [ ] **Shovel Plugin**: Configure message forwarding between brokers
- [ ] **HAProxy Integration**: Reverse proxy for management UI with authentication
- [ ] **Docker Secrets**: Replace environment variables with Docker secrets

## References

- [RabbitMQ Official Documentation](https://www.rabbitmq.com/documentation.html)
- [RabbitMQ Management Plugin](https://www.rabbitmq.com/management.html)
- [AMQP 0-9-1 Protocol Reference](https://www.rabbitmq.com/amqp-0-9-1-reference.html)
- [Virtual Hosts](https://www.rabbitmq.com/vhosts.html)
- [Access Control (Authentication, Authorisation)](https://www.rabbitmq.com/access-control.html)
- [Monitoring RabbitMQ](https://www.rabbitmq.com/monitoring.html)

---

**Last Updated**: February 12, 2026  
**Project**: Ouranos Infrastructure  
**Approval**: Red Panda Approved™