Flagger vs Terraform

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.

Terraform is an infrastructure-as-code tool for defining, provisioning, and managing cloud and on-premises resources through human-readable configuration files. Its core process is to write a configuration, review an execution plan, then apply approved changes. Providers connect Terraform to services through APIs, and the Terraform Registry lists providers for AWS, Azure, Google Cloud, Kubernetes, GitHub, and Splunk. Modules package reusable infrastructure configurations that users can find or publish in the Registry. The free Community Edition is a downloadable command-line tool. HCP Terraform adds remote execution, repository connections to GitHub, GitLab, and Bitbucket that can trigger plans after changes, and an API. It stores state remotely with encryption at rest and offers workspaces, single sign-on, and role-based access controls. HCP Terraform and Terraform Enterprise support Sentinel policies. HashiCorp cautions that policy-as-code is a guardrail, not a security boundary, and trusted providers and modules matter because they can access workspace variables and state. Downloads are available for Windows, macOS, and Linux.