Adopt a live database

For a team whose database already exists: read it into declarations and a baseline migration, then change it only through migrations.

Works

• yodel init --from <env> reads the live database into src/ and plans it back to no change before it writes anything
• A baseline migration recorded as applied, with none of its statements run
• Access adopted with the tables when the environment manages it: policies and grants, and on ClickHouse users and roles
• yodel init --baseline for another environment that holds the same schema

Differs

By database

ClickHouse

• A project owns ClickHouse databases (yodel create <dir> --clickhouse --database <name>).
• A rebuild keeps the old table until yodel cleanup drops it, and lint flags mutations and rebuilds (ch-mutation, ch-rebuild).

Postgres

• A project owns Postgres schemas (yodel create <dir> --postgres --schema <name>).
• Roles stay the environment's: the schema declares the policies and grants that name them.

By forge

GitHub

• The writer's secrets are secrets of a GitHub environment limited to main.
• The plan comment and the drift issue use the job's own token.

GitLab

• The writer's variables are protected and scoped to the environment; the readers' are not protected.
• The plan comment and the drift issue need GITLAB_TOKEN, and each drift watch runs from a pipeline schedule you create.

Forgejo

• Secrets belong to the repository, with no environments, so limit who can push branches.
• Jobs need a runner with the docker label, and a job gets no OIDC token for cloud roles.

First step

YODEL_CREDENTIALS=writer npx yodel init --from <env> --force

Adopting an existing database

Proof

Each claim runs what this room relies on against a real server, once plain (it passes) and once with the behaviour broken (the claim catches it). Claims status lists every claim.

Claim	What it says	Plain, broken
adopt	yodel init --from adopts a live database without touching it, and yodel plan then shows no change; on Postgres its policies, row-level security and grants too, on ClickHouse its dictionaries, functions, roles, users, row policies and grants; yodel init --baseline records the baseline, behind the gate, in a second environment that holds the same schema, and refuses one that differs	ClickHouse: pass, caughtPostgres: pass, caught

Then read

Tasks

Starting a projectSetting up each forge

Background

The two workflowsAccess control

Reference

The commandsInstalling and configuring