# fluxcd/flagger

Progressive delivery Kubernetes operator (Canary, A/B Testing and Blue/Green deployments)

Repository: https://github.com/fluxcd/flagger
Canonical: https://ross.abutalabs.com/products/flagger
Homepage: https://docs.flagger.app/main
Language: Go
License: Apache-2.0
License Family: permissive
Topics: progressive-delivery, kubernetes, gitops, canary, ab-testing, istio, aws-appmesh, linkerd, nginx, gloo, contour
Last push: 2026-08-24T11:28:14+00:00

## Health v2 (maintenance only)
Score: 89/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 70, longevity 100
- inputs: {"age_days": 2905, "days_push": 9, "days_rel": 43, "gap_med": 106, "n_releases_24m": 6}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5395, forks 803 (observed 2026-08-28T04:09:17.317273+00:00)

## What it is
Flagger is a progressive delivery Kubernetes operator that automates canary releases, A/B testing, and Blue/Green deployments by gradually shifting traffic to new versions while analyzing metrics and running conformance tests. It is a CNCF graduated project in the Flux GitOps family and integrates with service meshes (Istio, Linkerd, Kuma, App Mesh) and ingress controllers (NGINX, Contour, Gloo, Traefik, Gateway API).

## Use cases
- automate canary deployments on kubernetes
- zero downtime releases with traffic shifting
- a/b testing with session affinity for frontend apps
- blue/green deployments with traffic mirroring
- gitops-driven progressive delivery with flux
- automated rollback when metrics degrade
- canary analysis with prometheus metrics

## When to choose
- you run services on Kubernetes and want automated, metrics-driven rollouts
- you use a service mesh or ingress controller and need gradual traffic shifting
- you practice GitOps with Flux and want declarative release automation
- you need automatic rollback on failed canary analysis or conformance tests

## When to avoid
- your workloads are not on Kubernetes
- you have no metrics backend (Prometheus, Datadog, etc.) to drive analysis
- you need simple CI/CD pipelines without progressive delivery
- you deploy to VMs or bare metal outside a cluster

## Facets
- artifact type: service
- maturity: stable
- function: deployment, monitoring, alerting, ci-cd, feature-flags, load-testing
- domain: cloud-computing, microservices, monitoring
- platform: cloud, self-hosted, go
- tags: progressive-delivery, canary-deployment, gitops, ab-testing, blue-green-deployment, service-mesh, istio, linkerd, kubernetes-operator, cncf, traffic-shifting, prometheus, devops, containers, automation, kubernetes, docker

## Member repositories
- fluxcd/flagger (main) score 89

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:17.317273+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:58:23.084322+00:00, confidence not recorded.
  - readme: https://github.com/fluxcd/flagger (fetched 2026-08-28T04:09:17.317273+00:00, sha ec52a7e60738)
  - homepage: https://docs.flagger.app/main (fetched 2026-08-29T08:52:40.683777+00:00, sha 065273cfe592)
  - site_page: https://docs.flagger.app/main/faq (fetched 2026-08-29T08:52:40.688087+00:00, sha d0a31c9d03e9)
  - site_page: https://docs.flagger.app/main/install/flagger-install-on-kubernetes (fetched 2026-08-29T08:52:40.691001+00:00, sha af1df7399532)
  - site_page: https://docs.flagger.app/main/install/flagger-install-with-flux (fetched 2026-08-29T08:52:40.693625+00:00, sha 4ff3285206c7)
- Data as of 2026-08-30T08:39:29.467469+00:00.