Flagger is an open source automation tool for progressive delivery on Kubernetes.
According to the project’s GitHub page, Flagger helps to reduce the risks associated with introducing new software versions in production. It shifts traffic to the latest version of an application gradually and measures metrics and runs conformance tests as it does this.
It utilizes several deployment strategies, including canary release, A/B testing, and Blue/Green mirroring. Traffic routing is handled using either a service mesh or ingress controller.
It offers querying with Prometheus, Datadog, New Relic, CloudWatch, Dynatrace, InfluxDB, and Stackdriver for release analysis. Alerts can be provided through Slack, Microsoft Teams, Discord, Rocket, or Google Chat.
The latest version of Flagger is 1.19.0. The biggest addition in this release is Kubernetes Gateway API support. The benefits of this is that it models more infrastructure components, leading to improved deployment and management options.
The Gateway API exposes a more general API (compared to Ingress) for proxying and can be used in more protocols than just HTTP.