Как реализовать blue-green и canary деплой?

# 1. Развернуть green рядом с blue
helm upgrade --install orders-green ./chart --set color=green --set image.tag=1.4.2
# 2. Проверить через preview-сервис
./smoke-tests.sh http://orders-preview.shop.svc
# 3. Переключить трафик
kubectl patch service orders-api -p '{"spec":{"selector":{"app":"orders","color":"green"}}}'
# 4. Откат (если нужно) — вернуть selector на blue; blue удаляют после периода наблюдения

apiVersion: argoproj.io/v1alpha1
kind: Rollout
metadata: { name: orders-api }
spec:
  replicas: 10
  selector: { matchLabels: { app: orders-api } }
  template: { ... }                                   # как в Deployment
  strategy:
    canary:
      canaryService: orders-api-canary
      stableService: orders-api-stable
      trafficRouting:
        nginx: { stableIngress: orders-api }            # или istio / Gateway API
      steps:
        - setWeight: 5
        - pause: { duration: 10m }
        - analysis: { templates: [ { templateName: error-rate } ] }
        - setWeight: 25
        - pause: { duration: 10m }
        - analysis: { templates: [ { templateName: error-rate } ] }
        - setWeight: 50
        - pause: { duration: 10m }
---
apiVersion: argoproj.io/v1alpha1
kind: AnalysisTemplate
metadata: { name: error-rate }
spec:
  metrics:
    - name: error-rate
      interval: 1m
      failureLimit: 2
      successCondition: result[0] < 0.01             # < 1% ошибок 5xx
      provider:
        prometheus:
          address: http://prometheus:9090
          query: |
            sum(rate(http_server_request_duration_seconds_count{service="orders-api-canary",http_response_status_code=~"5.."}[2m]))
            / sum(rate(http_server_request_duration_seconds_count{service="orders-api-canary"}[2m]))

builder.Services.AddFeatureManagement();

app.MapPost("/checkout", async (IFeatureManager features, CheckoutRequest req) =>
    await features.IsEnabledAsync("NewCheckout")
        ? await newCheckout.HandleAsync(req)
        : await oldCheckout.HandleAsync(req));

{
  "FeatureManagement": {
    "NewCheckout": {
      "EnabledFor": [ { "Name": "Microsoft.Percentage", "Parameters": { "Value": 10 } } ]
    }
  }
}