Flagger vs Spinnaker
Flagger
flagger.app
Spinnaker
spinnaker.ioSide by side
| Figure | Flagger | Spinnaker |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | — | Yes |
| API | — | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Progressive Delivery Software | 8.2 (#11) | 7.2 (#23) |
| Spec score · Kubernetes Deployment Tools | 8.1 (#11) | 7.3 (#23) |
| Spec score · Rollback Management | 8.1 (#10) | 7.3 (#17) |
| Spec score · Continuous Delivery Software | 8.0 (#15) | 7.2 (#27) |
| Deployment strategies | It supports canary releases, A/B testing, and blue/green deployments. | Built-in strategies include blue/green and canary deployments, and users can define custom strategies. |
| Purpose | Flagger automates progressive delivery for applications running on Kubernetes by shifting traffic gradually while measuring metrics and running conformance tests. | Spinnaker is an open-source, multi-cloud continuous delivery platform for releasing software changes. |
| Support | The project directs users to its documentation, the CNCF community Slack #flagger channel, Flux talks, and GitHub issues for help. | The homepage says Slack is the fastest way to get questions answered. |
Plans
In their own words
Flagger
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.
Spinnaker
Spinnaker is a free, open-source, self-hosted multi-cloud continuous delivery platform for releasing software changes. Its pipelines can run integration and system tests, manage server groups, monitor rollouts, and start from Git, Jenkins, Travis CI, Docker, or CRON events. Built-in blue/green and canary strategies are available, and teams can define custom strategies. Documented providers include AWS, Azure, Cloud Foundry, Google Compute Engine, Kubernetes, Oracle Cloud, and App Engine. At least one provider must be enabled and configured before applications can be deployed. CI integrations include Jenkins, Travis, AWS CodeBuild, Concourse, Google CodeBuild, and Artifactory; source integrations include GitHub, Bitbucket Server/Stash, and GitLab. Authentication supports OAuth 2.0, SAML, or LDAP, while authorization can use groups or team-based role providers. SSL secures UI and API communication. Kubernetes is the recommended installation route, with local Debian packages documented for smaller deployments. The local guide recommends at least four cores and 16GB RAM and warns that single-machine installations may have downtime.