cozystack/docs/agents/overview.md

Cozystack Project Overview

This document provides detailed information about Cozystack project structure and conventions for AI agents.

About Cozystack

Cozystack is an open-source Kubernetes-based platform and framework for building cloud infrastructure. It provides:

• Managed Services: Databases, VMs, Kubernetes clusters, object storage, and more
• Multi-tenancy: Full isolation and self-service for tenants
• GitOps-driven: FluxCD-based continuous delivery
• Modular Architecture: Extensible with custom packages and services
• Developer Experience: Simplified local development with cozyhr tool

The platform exposes infrastructure services via the Kubernetes API with ready-made configs, built-in monitoring, and alerts.

Code Layout

.
├── packages/               # Main directory for cozystack packages
│   ├── core/              # Core platform logic charts (installer, platform)
│   ├── system/            # System charts (CSI, CNI, operators, etc.)
│   ├── apps/              # User-facing charts shown in dashboard catalog
│   └── extra/             # Tenant-specific modules, singleton charts which are used as dependencies
├── dashboards/            # Grafana dashboards for monitoring
├── hack/                  # Helper scripts for local development
│   └── e2e-chainsaw/     # End-to-end application tests (Kyverno Chainsaw)
├── scripts/               # Scripts used by cozystack container
│   └── migrations/       # Version migration scripts
├── docs/                  # Documentation
│   ├── agents/           # AI agent instructions
│   └── changelogs/       # Release changelogs
├── cmd/                   # Go command entry points
│   ├── cozystack-api/
│   ├── cozystack-controller/
│   └── cozystack-assets-server/
├── internal/              # Internal Go packages
│   ├── controller/       # Controller implementations
│   └── lineagecontrollerwebhook/
├── pkg/                   # Public Go packages
│   ├── apis/
│   ├── apiserver/
│   └── registry/
└── api/                   # Kubernetes API definitions (CRDs)
    └── v1alpha1/

Package Structure

Every package is a Helm chart following the umbrella chart pattern:

packages/<category>/<package-name>/
├── Chart.yaml                           # Chart definition and parameter docs
├── Makefile                             # Development workflow targets
├── charts/                              # Vendored upstream charts
├── images/                              # Dockerfiles and image build context
├── patches/                             # Optional upstream chart patches
├── templates/                           # Additional manifests
├── templates/dashboard-resourcemap.yaml # Dashboard resource mapping
├── values.yaml                          # Override values for upstream
└── values.schema.json                   # JSON schema for validation and UI

Build and Development Commands

Root targets (run from the repo root):

make build          # Build all Docker images (needs: docker, skopeo, jq, gh, helm, yq, GNU tar/sed/awk)
make unit-tests     # Run unit tests (requires bats-core >= 1.5; GNU parallel is optional)
make test-controllers # Run the Go tests under ./internal/... (controllers, contract tests)
make generate       # Code generation (hack/update-codegen.sh) — CRDs, DeepCopy, clients, RBAC
make manifests      # Generate CRD manifests and operator YAML variants
make cozypkg        # Build the cozypkg CLI
make test           # Full E2E tests (requires a cluster)
make prepare-env    # Prepare the E2E test environment (apply + prepare-cluster)

Per-package targets (run inside packages/{apps,system,extra,core}/<name>/):

make image          # Build the package image
make show           # Render the Helm template
make apply          # Apply the Helm release to a cluster (needs NAME, NAMESPACE)
make diff           # Diff the template against the cluster
make test           # Package-specific tests
make generate       # Regenerate values.schema.json + README.md from values.yaml

Build environment variables:

• REGISTRY — Docker registry (default ghcr.io/cozystack/cozystack).
• PUSH=1 / LOAD=0 — control buildx push/load behaviour.
• LOAD=1 PUSH=0 — load images locally instead of pushing. Builds for the host architecture only, because the classic docker image store cannot load a multi-platform index.
• PLATFORM — the buildx platforms. Defaults to linux/amd64,linux/arm64 for anything but LOAD=1, so a push from either architecture publishes an index both can run. Needs a docker-container builder (BUILDER) or a docker daemon on the containerd image store, with QEMU registered for the non-native half. Compiling builder stages run natively on $BUILDPLATFORM and cross-compile for the target, but every RUN step of a stage that runs on the target platform (package installs, setcap, install scripts, patch steps) still runs emulated. packages/core/testing pins linux/amd64, because it carries an x86 KVM sandbox. packages/core/talos builds the Talos installer and release assets for the arches in PLATFORM with the upstream imager, which needs no QEMU for either; its matchbox image carries the amd64 and arm64 kernel and initramfs whatever PLATFORM says, because it network-boots machines of either arch.
• PUSHED_TAGS_LOG — a file the image-tags macro appends every pushed <repo>:<tag> to, one per line. Unset by default; the release build sets it so hack/stitch-multiarch.sh can move every tag it pushed, versioned ones included, onto the multi-arch index. The append happens at recipe expansion, so make -n writes it too.
• CACHE_TAG — the tag of the mode=max build cache each image reads (and writes under WRITE_CACHE=1). Defaults to buildcache. Apart from the Talos installer and matchbox in the release job, CI builds one architecture per job, and builds arm64 images only for pre-release tags and in a nightly build of main: the images are built again on native arm64 runners under <tag>-arm64 with CACHE_TAG=buildcache-arm64, which only the nightly writes. The talos and testing packages get no arm64 leg: the release job builds the Talos installer and matchbox for both arches itself, and testing is amd64 only. For a pre-release, hack/stitch-multiarch.sh then joins each pair into one index, hack/verify-multiarch.sh fails the rc on any pinned image that is not an amd64+arm64 index, and the packages artifact is republished pinned on the index digests; see docs/release.md. The stitch skips any image whose digest is also pinned in a file it does not rewrite, which then fails that gate; the kamaji control-plane provider's gzipped manifest is the one such copy it does rewrite (see docs/agents/image-refs.md).

Values schema generation

Package values.yaml files carry annotations (@param, @typedef, @field, @enum, @section) that cozyvalues-gen turns into values.schema.json and README.md. Run make generate in the package after editing annotations. A pre-commit hook runs make generate across packages/apps/* and packages/extra/* on every commit to keep these in sync — see contributing.md for the regenerate-before-commit rule.

A chart also declares the limits on its own resource name there, with ## @name {string} - <why> followed by the constraint tags (@maxLength, @minLength, @pattern) it needs. cozyvalues-gen publishes the declaration at the root of values.schema.json as x-cozystack-name, from where hack/update-crd.sh carries it into the ApplicationDefinition, and the aggregated API server enforces it on metadata.name for whatever kind the definition describes. The description is the message a rejected name is answered with, so write it as the explanation of the limit. A @pattern is unanchored, as JSON Schema specifies, so one meant for the whole name is written ^...$. A declaration the server cannot enforce as written — a constraint keyword it does not implement, a wrong type, a null, lengths no name satisfies, a pattern that is not RE2 — refuses every create of that kind with a configuration error rather than being dropped. A pattern is checked only to compile, not to match anything, so one that matches no name ($^) rejects every name with the pattern as the reason. Annotation keywords such as title or examples, and x- extensions, are ignored. A cap only ever tightens: prefix + name must still fit the 53-character Helm release name limit, and a declaration looser than that budget does not widen it. The limits belong in the chart because that is where the facts behind them are — which sub-resources it renders and what release names they take — and a chart that needs nothing beyond the platform-wide limits declares nothing.

Testing

• Helm and BATS unit tests: make helm-unit-tests runs hack/helm-unit-tests.sh over every package that defines a test target. A test target is expected to run helm-unittest: the sweep fails a package whose run reports no suite, because exiting 0 having asserted nothing is indistinguishable from passing. A target that drives something else belongs under another name, as packages/core/testing already does with its sandbox flow. make bats-unit-tests requires bats-core 1.5 or newer; GNU parallel is optional and the target runs serially without it. Run the complete local BATS and POSIX-compatibility pass with pre-commit run bats-unit-tests --hook-stage manual --all-files; pull-request CI runs both lanes for code changes and the BATS contracts for docs-only changes. On a host whose /bin/sh differs from CI, make BATS_POSIX_SHELL=dash bats-posix-compat-tests selects the same interpreter explicitly. make unit-tests runs the full unit suite — Helm, BATS, the targeted POSIX-shell compatibility pass, Go, and the preset/readiness checks. It does not include the controller tests under ./internal/...; run make test-controllers as well. CI invokes both targets together.
• E2E tests: Kyverno Chainsaw suites in hack/e2e-chainsaw/ (one directory per app), run with chainsaw test. Cluster bootstrap (hack/e2e-install-cozystack.bats) and the OpenAPI checks (hack/e2e-test-openapi.bats) remain BATS. Conventions for writing and stabilising them — and the CI that runs them — live in e2e-testing.md.
• Go tests: standard go test, with Ginkgo/Gomega for controllers.

Conventions

Helm Charts

• Follow umbrella chart pattern for system components
• Include upstream charts in charts/ directory (vendored, not referenced)
• Override configuration in root values.yaml
• Use values.schema.json for input validation and dashboard UI rendering

Go Code

• Follow standard Go conventions and idioms
• Use controller-runtime patterns for Kubernetes controllers
• Prefer kubebuilder for API definitions and controllers
• Add proper error handling and structured logging

Git Commits

Conventional Commits (type(scope): description) with --signoff, kept atomic and focused. Full format, scopes, AI-attribution trailer, and PR workflow are in contributing.md — the source of truth; do not duplicate them here.

PackageSource CRD upgrade policy

Each component in a PackageSource may set install.upgradeCRDs to control how CRDs from the chart's crds/ directory are handled on HelmRelease upgrades. Allowed values: Skip (default — helm-controller does not touch CRDs on upgrade), Create (create new CRDs only), CreateReplace (create new and overwrite existing).

Set upgradeCRDs: CreateReplace for operators whose upstream regularly adds new CRDs between versions (etcd-operator, cnpg, kubevirt, kamaji). Without it, new CRDs from a chart bump do not land on existing clusters — only fresh installs get them.

Do not set CreateReplace blindly: it overwrites every CRD in crds/ and can cause silent data loss if upstream drops a field from a CRD that has live objects. Only enable it for operators whose schema evolution is additive-only. When in doubt, leave it unset and apply new CRDs manually.

Documentation

Documentation is organized as follows:

• docs/ - General documentation
• docs/agents/ - Instructions for AI agents
• docs/changelogs/ - Release changelogs
• Main website: https://github.com/cozystack/website

Domain references for specific tasks

Before working on these areas, read the relevant doc first:

• Backup subsystem design: api/backups/v1alpha1/DESIGN.md
• A new app package: copy the structure of an existing one (e.g. packages/apps/postgres/)

Things Agents Should Not Do

Never Edit These

• Do not modify files in /vendor/ (Go dependencies)
• Do not edit generated files: zz_generated.*.go
• Do not change go.mod/go.sum manually (use go get)
• Do not edit upstream charts in packages/*/charts/ directly (use patches)
• Do not modify image digests in values.yaml (generated by build)

Version Control

• Do not commit built artifacts from _out
• Do not commit test artifacts or temporary files

Git Operations

• Do not force push to main/master
• Do not update git config
• Do not perform destructive operations without explicit request

Core Components

• Do not modify packages/core/platform/ without understanding migration impact