# Story 3.3: Service Loader and Initialization

## Metadata
- **Story ID**: 3.3
- **Title**: Service Loader and Initialization
- **Epic**: 3 - Module Framework (Feature Services)
- **Status**: Pending
- **Priority**: High
- **Estimated Time**: 6-8 hours
- **Dependencies**: 3.1, 1.2, 1.7

## Goal
Implement service initialization helpers for feature services with dependency resolution, Consul registration, and automatic migration execution. Each service initializes itself in its own entry point.

## Description
This story implements service initialization helpers that feature services use in their entry points (`cmd/{service}/main.go`). Services initialize themselves, resolve dependencies (other services), register with Consul, run migrations, and start their gRPC servers. The loader provides helpers for common service initialization patterns.

## Deliverables

### 1. Service Initialization Helpers (`internal/service/init.go`)
- `InitializeService(cfg, module IModule)` function
- Bootstrap core kernel services
- Initialize service-specific components
- Register with Consul service registry
- Run database migrations (per-service schema)
- Start gRPC server
- Handle graceful shutdown

### 2. Service Dependency Resolution (`internal/service/deps.go`)
- Resolve service dependencies (check other services are available via Consul)
- Wait for dependent services to be healthy
- Service discovery integration
- Dependency validation

### 3. Service Bootstrap Pattern (`internal/service/bootstrap.go`)
- Common bootstrap pattern for feature services
- FX lifecycle integration
- Service registration helpers
- Health check setup
- Migration runner (per-service)

### 4. Service Template/Scaffolding
- Service template generator
- Standard service structure
- Example service entry point

**Note:** Each feature service has its own `cmd/{service}/main.go` that uses these helpers to initialize itself.

## Implementation Steps

1. **Create Service Initialization Helpers**
   - Create `internal/service/init.go`
   - Implement service bootstrap pattern
   - Integrate with Consul service registry

2. **Implement Dependency Resolution**
   - Create `internal/service/deps.go`
   - Check service dependencies via Consul
   - Wait for services to be healthy

3. **Create Service Bootstrap**
   - Create `internal/service/bootstrap.go`
   - Common bootstrap pattern
   - FX lifecycle integration

4. **Create Service Template**
   - Service template generator
   - Example service entry point

5. **Test Service Initialization**
   - Test service startup
   - Test Consul registration
   - Test dependency resolution

## Acceptance Criteria
- [x] Service initialization helpers work correctly
- [x] Services register with Consul automatically
- [x] Service migrations run on startup (per-service schema)
- [x] Service dependency resolution works via Consul
- [x] Services wait for dependencies to be healthy
- [x] FX lifecycle integration works
- [x] Service bootstrap pattern is reusable
- [x] Service template generator creates standard structure

## Related ADRs
- [ADR-0021: Module Loading Strategy](../../adr/0021-module-loading-strategy.md)
- [ADR-0029: Microservices Architecture](../../adr/0029-microservices-architecture.md)
- [ADR-0030: Service Communication Strategy](../../adr/0030-service-communication-strategy.md)
- [ADR-0033: Service Discovery Implementation](../../adr/0033-service-discovery-implementation.md)

## Files to Create/Modify
- `internal/service/init.go` - Service initialization helpers
- `internal/service/deps.go` - Service dependency resolution
- `internal/service/bootstrap.go` - Service bootstrap pattern
- `internal/service/template.go` - Service template generator
- Example: `cmd/blog-service/main.go` - Example service entry point

