BOSH

BOSH is an open-source toolchain for the release engineering, deployment, and lifecycle management of large-scale distributed systems. It provides a way to package software into releases, create reusable deployment manifests, and manage their deployment across heterogeneous IaaS platforms. BOSH emphasizes reproducibility, verifiability, and automation, enabling upgrades, rollbacks, and ongoing health management with idempotent operations.

The architecture centers on a BOSH Director, a long-running service that orchestrates deployments. It interacts with cloud providers through the Cloud Provider Interface and uses stemcells, which are minimal operating system images, to provision virtual machines. Software is delivered in releases that bundle one or more jobs and related packages. Deployments declare instance groups (collections of VMs), the jobs they should run, networking, and configuration. Each VM runs a BOSH agent that reports health, applies updates, and restarts processes as directed. The Director records state in declarative manifests and can perform upgrades, scaling, and rollbacks automatically. BOSH operates across major public clouds (AWS, GCP, Azure) and on-premises platforms (vSphere, OpenStack, etc.) via pluggable CPIs and cloud-config.

Typical workflow involves creating or updating releases, uploading them to a Director, importing a stemcell, and writing a deployment manifest. The operator runs bosh deploy to instantiate or update the deployment, with progress tracked by BOSH tasks. The system coordinates VM provisioning, agent onboarding, service startup, and health checks, and supports scaling, one-off commands, and automated rollback if failures occur. Releases are versioned, and upgrades usually require updating the release or stemcell and redeploying, with attention to state and data.

History and usage: BOSH originated within the Cloud Foundry ecosystem in the early 2010s as a general-purpose deployment and lifecycle tool. It is open-source software under an Apache 2.0 license and is maintained by a community of contributors and corporate sponsors.