# PostgreSQL Proxy Project Execution Plan
## Project Overview
Build a simple TCP proxy that forwards PostgreSQL connections to different target databases (including SSH-tunneled connections) based on configuration, allowing services to use a single connection string while dynamically switching backends.
## Phase 1: Setup & Basic Implementation (Week 1)
### Day 1-2: Project Setup
- [ ] Choose language (Go or Rust - decision needed)
- [ ] Initialize project structure
- [ ] Set up basic logging framework
- [ ] Create configuration structure (YAML/JSON)
- [ ] Define basic command-line interface
### Day 3-5: Core Proxy Implementation
- [ ] Implement basic TCP listener
- [ ] Create connection forwarding logic
- [ ] Add configuration parsing
- [ ] Test with local PostgreSQL instances
- [ ] Implement graceful shutdown
### Configuration Structure
```yaml
proxy:
listen_port: 5433
target:
host: "postgres1.local"
port: 5432
ssh:
enabled: false
```
## Phase 2: SSH Integration (Week 2)
### Day 1-3: SSH Tunnel Support
- [ ] Add SSH client library
- [ ] Implement SSH tunnel creation
- [ ] Add certificate-based authentication
- [ ] Test with remote PostgreSQL over SSH
### Day 4-5: Connection Management
- [ ] Implement connection pooling to targets
- [ ] Add health checking for target databases
- [ ] Handle SSH connection failures gracefully
### Enhanced Configuration
```yaml
targets:
production:
host: "prod-db.example.com"
port: 5432
ssh:
enabled: true
host: "bastion.example.com"
user: "dbuser"
key_file: "/path/to/cert.pem"
development:
host: "localhost"
port: 5432
ssh:
enabled: false
active_target: "production"
```
## Phase 3: Dynamic Switching (Week 3)
### Day 1-3: Configuration Hot-Reload
- [ ] Implement configuration file watching
- [ ] Add graceful connection draining
- [ ] Test switching between targets without dropping connections
### Day 4-5: Control Interface
- [ ] Add HTTP API for runtime control
- [ ] Implement health check endpoint
- [ ] Add metrics/status endpoint
### Control API
```
GET /health
POST /switch-target
GET /status
GET /metrics
```
## Phase 4: Production Readiness (Week 4)
### Day 1-2: Error Handling & Logging
- [ ] Comprehensive error handling
- [ ] Structured logging with levels
- [ ] Connection metrics and monitoring
- [ ] Proper resource cleanup
### Day 3-4: Testing & Documentation
- [ ] Unit tests for core functions
- [ ] Integration tests with real PostgreSQL
- [ ] Docker container setup
- [ ] README with usage examples
### Day 5: Deployment Preparation
- [ ] Systemd service file
- [ ] Configuration templates
- [ ] Performance testing
- [ ] Security review
## Technical Milestones
### Milestone 1: Basic Proxy (End of Week 1)
- Services can connect through proxy to single target
- Configuration-based target selection
- Basic logging and error handling
### Milestone 2: SSH Support (End of Week 2)
- SSH tunnel connections working
- Certificate-based authentication
- Connection health monitoring
### Milestone 3: Dynamic Switching (End of Week 3)
- Runtime target switching
- Graceful connection handling
- HTTP control interface
### Milestone 4: Production Ready (End of Week 4)
- Comprehensive testing
- Documentation complete
- Deployment artifacts ready
## Key Decisions Needed
### Immediate (Day 1)
- [ ] Language choice: Go vs Rust
- [ ] Configuration format: YAML vs JSON vs TOML
### Week 1
- [ ] Logging framework choice
- [ ] Configuration hot-reload approach
- [ ] Connection pooling strategy
### Week 2
- [ ] SSH library selection
- [ ] Health check implementation
- [ ] Error retry policies
## Risk Mitigation
### Technical Risks
- **SSH connection instability**: Implement connection retry with exponential backoff
- **PostgreSQL protocol complexity**: Start with simple TCP forwarding, add protocol awareness later if needed
- **Connection state during switching**: Implement graceful draining with timeout
### Timeline Risks
- **Scope creep**: Keep initial version simple, add features incrementally
- **SSH debugging**: Plan extra time for SSH certificate/networking issues
- **Testing complexity**: Use Docker for consistent test environments
## Success Criteria
### MVP (End of Week 2)
- All services use single connection string pointing to proxy
- Proxy forwards to configured PostgreSQL target
- SSH tunnel connections work with certificates
- Basic configuration switching works
### Production Ready (End of Week 4)
- Zero-downtime target switching
- Comprehensive error handling and logging
- Production deployment artifacts
- Documentation for operations team
## Next Steps
1. **Choose language** (Go vs Rust decision)
2. **Set up development environment**
3. **Create basic project structure**
4. **Start with simple TCP proxy implementation**
**Total estimated effort**: 3-4 weeks for production-ready solution.