Knit Deployment Tool

Knit is an open-source deployment tool developed at Pinterest for managing and orchestrating multi-service deployments across large-scale microservice architectures. Created by the Pinterest Infrastructure Engineering team (headquartered in San Francisco) to address the challenges of deploying hundreds of microservices to thousands of servers, Knit automates the complex workflows of building, testing, and deploying services in a safe and reversible manner. Key features: deployment pipeline: define deployment workflows as code, specifying build steps, test suites, staging environments, canary deployments, and production rollouts. Service discovery integration: integrates with service registries (SmartStack, ZooKeeper, Consul) for routing traffic to new versions during deployments. Canary deployments: support for gradual rollout strategies, sending a small percentage of traffic to the new version and monitoring error rates, latency, and business metrics before proceeding to full rollout. Automatic rollback: if deployment metrics (error rate, latency, alerting) exceed thresholds, Knit automatically rolls back to the previous stable version. Deployment strategies: rolling update, blue-green deployment, canary deployment, and custom strategies defined via plugins. Multi-environment support: deploy across development, staging, and production environments with environment-specific configurations. CI integration: integrates with continuous integration systems (Jenkins, Buildkite, GitHub Actions) to trigger deployments after successful builds. Dependency management: track and manage service dependencies to ensure correct deployment ordering. Audit trail: comprehensive logging of all deployment actions, including who deployed what, when, and why. Used at Pinterest to manage deployments across their infrastructure serving 450+ million monthly active users. Python-based with a web UI. Apache-2.0.