ln-774-healthcheck-setup

| Aspect | Details |

|--------|---------|

| Input | Context Store from ln-770 |

| Output | Health check endpoints and Kubernetes probe configuration |

| Stacks | .NET (AspNetCore.Diagnostics.HealthChecks), Python (FastAPI routes) |

---

Accept Context Store and scan for dependencies to monitor.

Required Context:

• STACK: .NET or Python
• PROJECT_ROOT: Project directory path

Idempotency Check:

• .NET: Grep for AddHealthChecks or MapHealthChecks
• Python: Grep for /health route
• If found: Return { "status": "skipped" }

Dependency Detection:

| Dependency | .NET Detection | Python Detection |

|------------|----------------|------------------|

| PostgreSQL | Npgsql in csproj | psycopg2 or asyncpg in requirements |

| MySQL | MySql.Data in csproj | mysql-connector-python in requirements |

| Redis | StackExchange.Redis in csproj | redis in requirements |

| RabbitMQ | RabbitMQ.Client in csproj | pika or aio-pika in requirements |

| MongoDB | MongoDB.Driver in csproj | pymongo in requirements |

---

Define three types of health endpoints per Kubernetes best practices.

Endpoint Types

| Endpoint | Probe Type | Purpose | Checks |

|----------|------------|---------|--------|

| /health/live | Liveness | Is app alive? | App responds (no dependency checks) |

| /health/ready | Readiness | Can app serve traffic? | All dependencies healthy |

| /health/startup | Startup (K8s 1.16+) | Is app initialized? | Initial warmup complete |

When Each Probe Fails

| Probe | Failure Action | Kubernetes Behavior |

|-------|----------------|---------------------|

| Liveness | Container restart | kubelet restarts container |

| Readiness | Remove from service | Traffic stopped, no restart |

| Startup | Delay other probes | Liveness/Readiness paused |

---

Use MCP tools for current documentation.

For .NET:

```

MCP ref: "ASP.NET Core health checks Kubernetes probes"

Context7: /dotnet/aspnetcore

```

For Python:

```

MCP ref: "FastAPI health check endpoint Kubernetes"

Context7: /tiangolo/fastapi

```

Key Patterns to Research:

1. Database health checks (connection pool)
2. Redis connectivity check
3. Custom health check implementation
4. Health check response writer customization

---

Determine probe timing based on application characteristics.

Probe Configuration

| Parameter | Liveness | Readiness | Startup |

|-----------|----------|-----------|---------|

| initialDelaySeconds | 10 | 5 | 0 |

| periodSeconds | 10 | 5 | 5 |

| timeoutSeconds | 5 | 3 | 3 |

| failureThreshold | 3 | 3 | 30 |

| successThreshold | 1 | 1 | 1 |

Startup Probe Calculation:

```

Max startup time = initialDelaySeconds + (periodSeconds × failureThreshold)

Default: 0 + (5 × 30) = 150 seconds

```

---

.NET Output Files

| File | Purpose |

|------|---------|

| Extensions/HealthCheckExtensions.cs | Health check registration |

| HealthChecks/StartupHealthCheck.cs | Custom startup check |

Generation Process:

1. Use MCP ref for current ASP.NET Core health checks API
2. Generate HealthCheckExtensions with:

- AddHealthChecks registration

- Database health check (if detected)

- Redis health check (if detected)

- Custom StartupHealthCheck

1. Configure three endpoints with proper tags

Packages to Add:

• AspNetCore.HealthChecks.NpgSql (if PostgreSQL)
• AspNetCore.HealthChecks.Redis (if Redis)
• AspNetCore.HealthChecks.MySql (if MySQL)

Registration Code:

```csharp

builder.Services.AddHealthCheckServices(builder.Configuration);

// ...

app.MapHealthCheckEndpoints();

```

Python Output Files

| File | Purpose |

|------|---------|

| routes/health.py | Health check router |

| services/health_checker.py | Dependency health checks |

Generation Process:

1. Use MCP ref for FastAPI health patterns
2. Generate health router with:

- /health/live endpoint (simple)

- /health/ready endpoint (with dependency checks)

- /health/startup endpoint

1. Generate health_checker service for dependency verification

Registration Code:

```python

from routes.health import health_router

app.include_router(health_router)

```

Kubernetes Manifest Snippet

Generate for inclusion in deployment.yaml:

```yaml

livenessProbe:

httpGet:

path: /health/live

port: 5000

initialDelaySeconds: 10

periodSeconds: 10

timeoutSeconds: 5

failureThreshold: 3

readinessProbe:

httpGet:

path: /health/ready

port: 5000

initialDelaySeconds: 5

periodSeconds: 5

timeoutSeconds: 3

failureThreshold: 3

startupProbe:

httpGet:

path: /health/startup

port: 5000

periodSeconds: 5

failureThreshold: 30

```

---

Validation Steps:

1. Syntax check:

- .NET: dotnet build --no-restore

- Python: python -m py_compile routes/health.py

1. Endpoint test:

```bash

curl http://localhost:5000/health/live

curl http://localhost:5000/health/ready

curl http://localhost:5000/health/startup

```

1. Verify response format:

```json

{

"status": "Healthy",

"checks": {

"database": { "status": "Healthy", "duration": "00:00:00.0234" },

"redis": { "status": "Healthy", "duration": "00:00:00.0012" }

},

"totalDuration": "00:00:00.0250"

}

```

1. Dependency failure test:

- Stop database

- Verify /health/ready returns 503

- Verify /health/live still returns 200

---

```json

{

"status": "success",

"files_created": [

"Extensions/HealthCheckExtensions.cs",

"HealthChecks/StartupHealthCheck.cs"

],

"packages_added": [

"AspNetCore.HealthChecks.NpgSql"

],

"registration_code": "builder.Services.AddHealthCheckServices(configuration);",

"message": "Configured health checks with liveness, readiness, and startup probes"

}

```

---

• [ASP.NET Core Health Checks](https://learn.microsoft.com/aspnet/core/host-and-deploy/health-checks)
• [Kubernetes Probes](https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/)
• [AWS EKS Health Check Best Practices](https://docs.aws.amazon.com/eks/latest/best-practices/application.html)

---

Version: 2.0.0

Last Updated: 2026-01-10