Flagger Has a Free API — Progressive Delivery for Kubernetes

#devops #cloudnative #cicd #kubernetes

Flagger: Canary Deployments Made Automatic

Deploying to production is terrifying. One bad release can take down everything. Flagger automates canary deployments, A/B testing, and blue/green deployments on Kubernetes — rolling back automatically when metrics go bad.

How Flagger Works

Flagger gradually shifts traffic to new versions while monitoring metrics. If error rates spike or latency increases, it automatically rolls back. Zero human intervention.

[v1: 100%] -> [v1: 90%, v2: 10%] -> [v1: 50%, v2: 50%] -> [v2: 100%]
                    | (if metrics bad)
              [v1: 100%] <- automatic rollback

The Free API (CRDs)

apiVersion: flagger.app/v1beta1
kind: Canary
metadata:
  name: my-app
spec:
  targetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: my-app
  service:
    port: 80
  analysis:
    interval: 30s
    threshold: 5
    maxWeight: 50
    stepWeight: 10
    metrics:
    - name: request-success-rate
      thresholdRange:
        min: 99
      interval: 1m
    - name: request-duration
      thresholdRange:
        max: 500
      interval: 1m

# Check canary status
kubectl get canaries -A

# Watch canary progression
kubectl describe canary my-app

# Manual promotion
kubectl annotate canary my-app flagger.app/promote=true

Supported Service Meshes

Istio — full feature support
Linkerd — lightweight option
App Mesh — AWS native
Contour — HTTPProxy based
Nginx Ingress — no mesh required
Gloo Edge — API gateway
Traefik — popular ingress

Real-World Use Case

An e-commerce platform was losing $50K per bad deployment. After implementing Flagger with Istio, bad releases get caught at 10% traffic — automatic rollback in under 2 minutes. Zero downtime incidents in 6 months.

Quick Start

helm repo add flagger https://flagger.app
helm install flagger flagger/flagger \\
  --namespace flagger-system \\
  --set meshProvider=istio \\
  --set metricsServer=http://prometheus:9090

Resources

Need automated data pipelines for your deployment metrics? Check out my data tools on Apify or email spinov001@gmail.com for custom automation.

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