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A deployment is described once, and every artifact built from it is generated from it

A deployment is described once, and every artifact built from it is generated from it

majordomus://rule/majordomus.deployment-contract@1active deploymentschemaprojection

Rationale

A Dockerfile and its ignore file written by hand restate what the repository already knows — the port the server binds, the routes it registers, the binary the workspace names, the paths a build reads — and every one of those pairs drifts the first time one half changes. The failure is silent and it is discovered in production: an image that runs a binary under a name nobody builds any more, a health check pointed at a route that was renamed, a machine sized for a memory figure a release outgrew.

The repository already refuses that shape everywhere else. A capability is declared once and projected into the CLI, HTTP, MCP, OpenAPI, the documentation and the site, and generate --check fails when a projection goes stale. A deployment is the same kind of fact and arrives the same way, or it does not arrive.

The second reason is money and disclosure. A deployment states how much runs and for how long, so the description has to be somewhere a reviewer reads rather than in a provider dashboard nobody diffs. And it must never hold the credential that authorises it: the contract has no field for one, and a token smuggled into a field that does exist is refused here.

Required behaviour

A deployment is a *.yaml object under the layer's deployments section, valid against share/schemas/majordomus/deployment/deployment.v1.schema.json (deployment/v1). It states the application, the package and binary shipped, the port and the interface the process listens on, the liveness and readiness routes, the resources, the machine count, the region and the build inputs — each exactly once. It names no hosting provider: none is a target, and a provider key is refused like any other key the contract does not have.

Keys are closed by share/allow/deployment.txt, generated from the schema: an unknown key is an error, never carried. Two objects may not claim one identity. min_running may not exceed count. A health route is a path, not a URL. The port is unprivileged, because the deployed process does not run as root.

Every artifact built from it — the container image definition and its ignore file — is written by majordomus generate from this object, carries a provenance header naming its source and its regeneration command, and is compared by generate --check. A contributor who edits a generated artifact is told which file to change instead.

Failure behaviour

A violation is a FAIL finding under the category deployment, naming the object, the key, the value found and the correction; the command that found it exits 10, and under watch it is drift and the command exits 11.

Verification

mj_validate_deployments decides it, dispatched from doctor, watch. The behavioural case test/cases/84_deployment_contract.sh proves it by mutation: an unknown key, a provider block, an unknown schema version, a missing required field, a privileged port, a min_running above count, a health route that is not a path, a duplicate identity and a credential in a field that exists — each refused by name; and a valid object reaching the index and the object listing with nothing registered anywhere.

Where this comes from

canonical file
.ai/repo/rules/vendor/majordomus/rules/deployment-contract.v1.md
identity
majordomus.deployment-contract@1
also served as
MCP resource majordomus://rule/majordomus.deployment-contract@1 · majordomus entity show rule/majordomus-deployment-contract-1 · GET /api/v1/entity?uri=majordomus://rule/majordomus.deployment-contract@1
in the Cockpit
/cockpit/objects/rule/majordomus-deployment-contract-1

This page is generated from the file above by scripts/generate-site-data; editing the page changes nothing, editing the file changes every surface. The relations above are edges of docs/generated/graph.json, which the executable writes from the same index.

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