Infrastructure Skill

Defines containerization and orchestration standards for .NET services.

Roles

• •Developer: Creates and maintains Dockerfile and Kubernetes manifests
• •Reviewer: Verifies infrastructure configuration meets standards

Dockerfile Standards

See templates/dockerfile.md for complete template.

Required Structure

1. •Multi-stage build: base → build → publish → final
2. •.NET 10 base images: mcr.microsoft.com/dotnet/aspnet:10.0 and sdk:10.0
3. •Non-root user: USER app
4. •Standard ports: 8080 (HTTP), 8081 (HTTPS)
5. •Build files: Copy Directory.*.props, global.json for proper restore

Build Arguments

Security

• •Never embed secrets in image layers
• •Use non-root user
• •Minimize image layers
• •Use specific image tags, not latest

Kubernetes Standards

See templates/kubernetes.md for complete templates.

Required Manifests

Kustomize Structure

tools/kubernetes/
├── base/
│   ├── kustomization.yaml
│   ├── deployment.yaml
│   └── service.yaml
└── overlays/
    ├── integration/
    ├── testing/
    ├── staging/
    └── production/

Variable Substitution

Use $(VARIABLE_NAME) syntax for Kustomize substitution:

• •$(APPLICATION_NAME) - Service name
• •$(IMAGE) - Container image with tag

Health Probes

Endpoints

Probe Configuration

Implementation

See .github/skills/dotnet-service-generator/references/health-check.md for health check patterns.

// Registration
services.AddHealthChecks()
    .AddCheck<MyServiceHealthCheck>("MyService", tags: ["ready"]);

// Endpoints
app.MapHealthChecks("/healthz/live", new HealthCheckOptions
{
    Predicate = _ => false // Always healthy if process is running
});

app.MapHealthChecks("/healthz/ready", new HealthCheckOptions
{
    Predicate = check => check.Tags.Contains("ready")
});

Resource Limits

Default Values

Ephemeral Storage

All environments:

• •Request: 1Gi
• •Limit: 2Gi

Adjustment Guidelines

• •Profile actual usage before adjusting
• •CPU limit should be 2x request for burst capacity
• •Memory limit should be 2x request for safety margin
• •Monitor OOMKilled events to detect memory pressure

Graceful Shutdown

Configuration

terminationGracePeriodSeconds: 60

Application Requirements

1. •Handle SIGTERM signal
2. •Stop accepting new requests
3. •Complete in-flight requests
4. •Close database connections
5. •Flush telemetry buffers
6. •Release distributed locks

.NET Implementation

// Program.cs
var builder = WebApplication.CreateBuilder(args);

// Configure graceful shutdown
builder.Host.ConfigureHostOptions(options =>
{
    options.ShutdownTimeout = TimeSpan.FromSeconds(30);
});

var app = builder.Build();

app.Lifetime.ApplicationStopping.Register(() =>
{
    // Cleanup logic here
});

Volumes and Secrets

Standard Mounts

Configuration Loading

builder.Configuration
    .AddJsonFile("appsettings.json", optional: false)
    .AddJsonFile($"appsettings.{env}.json", optional: true)
    .AddJsonFile("/app/configuration/configmap/appsettings.json", optional: true)
    .AddJsonFile("/app/configuration/secret/appsettings.json", optional: true)
    .AddEnvironmentVariables();

Deployment Strategy

Default: Rolling Update

strategy:
  type: RollingUpdate
  rollingUpdate:
    maxSurge: 0%
    maxUnavailable: 100%

This configuration:

• •Terminates all old pods before creating new ones
• •Minimizes resource usage during deployment
• •Suitable for stateless services

Alternative: Zero-Downtime

strategy:
  type: RollingUpdate
  rollingUpdate:
    maxSurge: 25%
    maxUnavailable: 0%

Use when:

• •Service must maintain availability during deployment
• •Sufficient cluster resources for extra pods

Reviewer Checklist

When reviewing infrastructure changes:

• • Multi-stage Dockerfile with proper layer ordering
• • Non-root user in container
• • Health probes configured with appropriate timing
• • Resource requests and limits defined
• • Graceful shutdown period set
• • Secrets mounted from Kubernetes Secrets (not ConfigMaps)
• • Image pull secrets configured
• • Environment-specific overlays for all environments
• • No hardcoded values (use Kustomize substitution)