The Stack Graph (Terminology)

Garden centers around the Stack Graph, which allows you to describe your whole stack in a consistent, structured way, without creating massive scripts or monolithic configuration files.

We believe your configuration should be distributed, like your stack, so your configuration files are located next to each module (such as container image, Helm chart, manifests and function). Garden scans for these configuration files, even across multiple repositories, validates them and compiles them into a graph that describes all the steps involved in building, deploying and testing your application.

Garden uses the graph to detect when modules need to be re-built or re-tested, services re-deployed etc. by comparing your current code with previously built, deployed and tested versions.

Structure and terminology

The Stack Graph is essentially an opinionated graph structure, with a handful of pre-defined entity types and verbs:

  • Project: The root of the graph. Contains one or more modules and configures providers.

  • Provider: Providers are configured at the project level. They take care of initializing deployment environments, and control what happens within each node of the graph, e.g. how modules are built, services are deployed etc. They also specify module types and how they are configured.

  • Module: A module is something you build. Each module specifies a type (e.g. container or helm) which dictates how it is configured, built, deployed etc. It can contain zero or more services, tasks and tests. It can also have build dependencies.

  • Service: A service is something you deploy. It can depend on other services, as well as tasks.

  • Task: A task is something you run and wait for to finish. It can depend on other services and tasks.

  • Test: A test is also something you run and wait for to finish, similar to tasks, but with slightly different semantics and separate commands for execution. It can depend on services and tasks (but notably services and tasks cannot depend on tests).

Each part of your stack describes itself using a simple configuration file. Garden collects all those declarations, validates, and compiles them into a DAG (a directed acyclic graph, meaning it must have no circular dependencies).

Additionally, Garden supports Workflows, which allow you to define a CI-like sequence of Garden commands and scripts to perform.

For more detail on all of the above, see the Using Garden section.

Pluggability

Importantly, what happens within each of the actions that the graph describes—building, deploying, running etc.—is completely pluggable via the providers. The Stack Graph is only opinionated in terms of flows and dependencies—what should happen when—but the how is pluggable.

All the Garden plugins are currently built-in; we will soon release a plugin SDK to allow any user to easily make their own plugins.

Next Steps

Head over to the Getting Started section to learn the basics on how to get up and running with Garden.

If you or your team has already set up a Garden project, you can also skip over to the Using Garden section, to learn more about the concepts and how to interact with Garden.