Database Schema Control

In most cases, database should be designed and created before writing any code. But since there would always be a chance that you may need to add new business logic or modify database configurations, migrations for database would be needed at that time.

Atlas

Atlas is a powerful database schema management tool to manage schema as code. It has two workflows that could not only manage migrations in traditional ways like Laravel migration, but could also find and apply changes to database overall schemas. You may find usage documentation here.

Here is an example to introduce versioned workflow with atlas to our bootcamp project:

Add configurations

Create a atlas.hcl file in the root directory:

atlas.hcl

env "local" {
  src = "file://manifest/database/tables/"
  dev = "docker://maria/latest/bootcamp"
  url = "maria://dbadmin:Password@localhost:3306/bootcamp"
  migration {
    dir = "file://manifest/database/migrations/"
  }
}
env "docker" {
  src = "file://manifest/database/tables/"
  dev = "docker://maria/latest/bootcamp"
  url = "maria://dbadmin:Password@database:3306/bootcamp"
  migration {
    dir = "file://manifest/database/migrations/"
  }
}

src: The database schema files directory, in our bootcamp project, we could create all tables in manifese/database/tables/ folder and use it as src.
dev: Dev Database is used to compute the diff by atlas.
url: Your database URL.
dir: The migration files directory.

Create migrations

There are some methods to use migrations with existing database in official documentation, but it would be much simple to use an empty database with docker. Just delete the old container and volume created before and run docker compose up -d --build without initial database tables.

Then run the following command to create migrations:

atlas migrate diff initial --env local

You will find a SQL file and a sum file created by atlas in manifest/database/migrations folder.

Apply migration

You can simple apply the initial database schema with:

atlas migrate apply --env local

To make it more convenient, we could modify our dockerfile:

Dockerfile

FROM golang:1.22-alpine as builder
WORKDIR /tmp
RUN wget -O gf "https://github.com/gogf/gf/releases/latest/download/gf_$(go env GOOS)_$(go env GOARCH)" && \
    chmod +x gf && \
    ./gf install -y && \
    rm ./gf

FROM golang:1.22-alpine as dev
WORKDIR /var/www
COPY --from=builder /go/bin/gf /go/bin/gf
COPY --from=arigaio/atlas:latest-alpine /atlas /usr/local/bin/atlas
COPY manifest/database/migrations /migrations
CMD atlas migrate apply --env docker && \
    gf run main.go

ENV DEBIAN_FRONTEND noninteractive
RUN apk add --no-cache tzdata
ENV TZ=Asia/Shanghai

Now migrations would be auto-applied when the container starts, and you can use atlas command tool in you container with --env docker argument.

Design Methodology Access Control