Running migrations in prod

In production, you'll want to run migrations as part of your deployment process. Here's how to do it with Kubernetes.

The deployment model

dibs needs two things to run migrations:

The dibs CLI binary
Your -db binary (the schema service)

The dibs CLI spawns your -db binary to read the schema, then applies migrations to the database.

Build the binaries

In your CI pipeline, build both binaries:

dockerfile

FROM rust:1.75 as builder

WORKDIR /app
COPY . .

# Build the db service binary
RUN cargo build --release -p my-app-db

# Install dibs CLI
RUN cargo install --git https://github.com/bearcove/dibs dibs-cli

Running migrations

Two common approaches:

Init container - Runs before your app starts, blocks deployment until complete. Good for: ensuring the app never starts with an outdated schema.

Separate Job - Runs independently, can be triggered by CI/CD. Good for: long-running migrations, separating migration failures from app deployments.

Both use the same container spec:

yaml

# Container spec (used in either approach)
- name: migrate
  image: my-app-migrations:latest
  env:
    - name: DATABASE_URL
      valueFrom:
        secretKeyRef:
          name: db-credentials
          key: url
  command: ["/usr/local/bin/dibs", "migrate"]
  volumeMounts:
    - name: config
      mountPath: /.config

For init container, add this to your Deployment's spec.template.spec.initContainers. For a Job, wrap it in a batch/v1 Job with restartPolicy: Never.

Config

Mount .config/dibs.styx via ConfigMap:

yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: dibs-config
data:
  dibs.styx: |
    @schema {id crate:dibs@1, cli dibs}

    db {
        crate my-app-db
        binary "/app/my-app-db"
    }

Container image

Your migration container needs:

/usr/local/bin/dibs (the CLI)
/app/my-app-db (your db binary)
/.config/dibs.styx (config)

Example Dockerfile:

dockerfile

FROM debian:bookworm-slim

# Install dibs CLI
COPY --from=builder /usr/local/cargo/bin/dibs /usr/local/bin/dibs

# Copy your db binary
COPY --from=builder /app/target/release/my-app-db /app/my-app-db

# Config will be mounted at runtime
RUN mkdir -p /.config

CMD ["/usr/local/bin/dibs", "migrate"]