Flagger vs zero

Flagger is a self-hosted Kubernetes operator that automates progressive delivery for applications running on Kubernetes. It gradually shifts traffic to a new version while checking measures such as HTTP or gRPC request success and latency. Deployment approaches include canary releases, A/B testing, and blue/green deployments, routed through an ingress controller or a service mesh compatible with the Kubernetes Gateway API. Built-in checks cover HTTP request success rate and duration; teams can add custom metrics and webhooks for acceptance tests, load tests, or other validation. Release analysis can query systems including Prometheus, Datadog, CloudWatch, New Relic, Graphite, Dynatrace, InfluxDB, and Google Cloud Monitoring. If SLO analysis detects a performance drop, Flagger rolls back the release automatically. Manual controls allow approval, pausing, or resuming deployments, and notifications can go to Slack, Microsoft Teams, Discord, or Rocket. It is configured through Kubernetes custom resources, works with Kubernetes-compatible CI/CD solutions, and can be used with Flux for GitOps canary pipelines. Flagger is Apache 2.0 licensed and free.

zero has no write-up on Specifiction yet; its figures are above.