---
title: Continuous Integration for Ent Projects
author: Rotem Tamir
authorURL: "https://github.com/rotemtam"
authorImageURL: "https://s.gravatar.com/avatar/36b3739951a27d2e37251867b7d44b1a?s=80"
authorTwitter: _rtam
image: "https://entgo.io/images/assets/ent-ci-post.png"
---

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';

To ensure the quality of their software, teams often apply _Continuous
Integration_ workflows, commonly known as CI. With CI, teams continuously run a suite
of automated verifications against every change to the code-base. During CI,
teams may run many kinds of verifications:

* Compilation or build of the most recent version to make sure it
  isn't broken.
* Linting to enforce any accepted code-style standards.
* Unit tests that verify individual components work as expected
  and that changes to the codebase do not cause regressions in
  other areas.
* Security scans to make sure no known vulnerabilities are introduced
  to the codebase.
* And much more!

From our discussions with the Ent community, we have learned
that many teams using Ent already use CI and would like to enforce some
Ent-specific verifications into their workflows.

To support the community with this effort, we added a new [guide](/docs/ci) to the docs which
documents common best practices to verify in CI and introduces
[ent/contrib/ci](https://github.com/ent/contrib/tree/master/ci): a GitHub Action
we maintain that codifies them.

In this post, I want to share some of our initial suggestions on how you
might incorporate CI to you Ent project.  Towards the end of this post
I will share insights into projects we are working on and would like to
get the community's feedback for.

## Verify all generated files are checked in

Ent heavily relies on code generation. In our experience, generated code
should always be checked into source control. This is done for two reasons:
* If generated code is checked into source control, it can be read
  along with the main application code. Having generated code present when
  the code is reviewed or when a repository is browsed is essential to get
  a complete picture of how things work.
* Differences in development environments between team members can easily be
  spotted and remedied. This further reduces the chance of "it works on my
  machine" type issues since everyone is running the same code.

If you're using GitHub for source control, it's easy to verify that all generated
files are checked in with the `ent/contrib/ci` GitHub Action.
Otherwise, we supply a simple bash script that you can integrate in your existing
CI flow.

<Tabs
    defaultValue="gh"
    values={[
        {label: 'GitHub Action', value: 'gh'},
        {label: 'Bash', value: 'bash'},
    ]}>
<TabItem value="gh">

Simply add a file named `.github/workflows/ent-ci.yaml` in your repository:

```yaml
name: EntCI
on:
  push:
  # Run whenever code is changed in the master.
    branches:
      - master
  # Run on PRs where something changed under the `ent/` directory.
  pull_request:
    paths:
      - 'ent/*'
jobs:
  ent:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3.0.1
      - uses: actions/setup-go@v3
        with:
          go-version: 1.18
      - uses: ent/contrib/ci@master
```

</TabItem>
<TabItem value="bash">

```bash
go generate ./...
status=$(git status --porcelain)
if [ -n "$status" ]; then
    echo "you need to run 'go generate ./...' and commit the changes"
    echo "$status"
    exit 1
fi
```

</TabItem>
</Tabs>

## Lint migration files

Changes to your project's Ent schema almost always result in a modification
of your database. If you are using [Versioned Migrations](/docs/versioned-migrations)
to manage changes to your database schema, you can run [migration linting](https://atlasgo.io/versioned/lint)
as part of your continuous integration flow. This is done for multiple reasons:

* Linting replays your migration directory on a [database container](https://atlasgo.io/concepts/dev-database) to
  make sure all SQL statements are valid and in the correct order.
* [Migration directory integrity](/docs/versioned-migrations#atlas-migration-directory-integrity-file)
  is enforced - ensuring that history wasn't accidentally changed and that migrations that are
  planned in parallel are unified to a clean linear history.
* Destructive changes are detected, notifying you of any potential data loss that may be
  caused by your migrations way before they reach your production database.
* Linting detects data-dependent changes that _may_ fail upon deployment and require
  more careful review from your side.

If you're using GitHub, you can use the [Official Atlas Action](https://github.com/ariga/atlas-action)
to run migration linting during CI.

Add `.github/workflows/atlas-ci.yaml` to your repo with the following contents:

<Tabs
defaultValue="mysql"
values={[
    {label: 'MySQL', value: 'mysql'},
    {label: 'MariaDB', value: 'maria'},
    {label: 'PostgreSQL', value: 'postgres'},
]}>
<TabItem value="mysql">

```yaml
name: Atlas CI
on:
  # Run whenever code is changed in the master branch,
  # change this to your root branch.
  push:
    branches:
      - master
  # Run on PRs where something changed under the `ent/migrate/migrations/` directory.
  pull_request:
    paths:
      - 'ent/migrate/migrations/*'
jobs:
  lint:
    services:
      # Spin up a mysql:8.0.29 container to be used as the dev-database for analysis.
      mysql:
        image: mysql:8.0.29
        env:
          MYSQL_ROOT_PASSWORD: pass
          MYSQL_DATABASE: test
        ports:
          - 3306:3306
        options: >-
          --health-cmd "mysqladmin ping -ppass"
          --health-interval 10s
          --health-start-period 10s
          --health-timeout 5s
          --health-retries 10
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3.0.1
        with:
          fetch-depth: 0 # Mandatory unless "latest" is set below.
      - uses: ariga/atlas-action@v0
        with:
          dir: ent/migrate/migrations
          dir-format: golang-migrate # Or: atlas, goose, dbmate
          dev-url: mysql://root:pass@localhost:3306/test
```

</TabItem>
<TabItem value="maria">

```yaml
name: Atlas CI
on:
  # Run whenever code is changed in the master branch,
  # change this to your root branch.
  push:
    branches:
      - master
  # Run on PRs where something changed under the `ent/migrate/migrations/` directory.
  pull_request:
    paths:
      - 'ent/migrate/migrations/*'
jobs:
  lint:
    services:
      # Spin up a maria:10.7 container to be used as the dev-database for analysis.
      maria:
        image: mariadb:10.7
        env:
          MYSQL_DATABASE: test
          MYSQL_ROOT_PASSWORD: pass
        ports:
          - 3306:3306
        options: >-
          --health-cmd "mysqladmin ping -ppass"
          --health-interval 10s
          --health-start-period 10s
          --health-timeout 5s
          --health-retries 10
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3.0.1
        with:
          fetch-depth: 0 # Mandatory unless "latest" is set below.
      - uses: ariga/atlas-action@v0
        with:
          dir: ent/migrate/migrations
          dir-format: golang-migrate # Or: atlas, goose, dbmate
          dev-url: maria://root:pass@localhost:3306/test
```

</TabItem>
<TabItem value="postgres">

```yaml
name: Atlas CI
on:
  # Run whenever code is changed in the master branch,
  # change this to your root branch.
  push:
    branches:
      - master
  # Run on PRs where something changed under the `ent/migrate/migrations/` directory.
  pull_request:
    paths:
      - 'ent/migrate/migrations/*'
jobs:
  lint:
    services:
      # Spin up a postgres:10 container to be used as the dev-database for analysis.
      postgres:
        image: postgres:10
        env:
          POSTGRES_DB: test
          POSTGRES_PASSWORD: pass
        ports:
          - 5432:5432
        options: >-
          --health-cmd pg_isready
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3.0.1
        with:
          fetch-depth: 0 # Mandatory unless "latest" is set below.
      - uses: ariga/atlas-action@v0
        with:
          dir: ent/migrate/migrations
          dir-format: golang-migrate # Or: atlas, goose, dbmate
          dev-url: postgres://postgres:pass@localhost:5432/test?sslmode=disable
```

</TabItem>
</Tabs>

Notice that running `atlas migrate lint` requires a clean [dev-database](https://atlasgo.io/concepts/dev-database)
which is provided by the `services` block in the example code above.

## What's next for Ent CI

To add to this modest beginning, I want to share some features that we are experimenting
with at [Ariga](https://ariga.io) with hope to get the community's feedback on them.

* *Linting for Online Migrations* - many Ent projects use the automatic schema migration
  mechanism that is available in Ent (using `ent.Schema.Create` when applications start).
  Assuming a project's source code is managed in a version control system (such as Git),
  we compare the schema in the mainline branch (`master`/`main`/etc.) with the one in the
  current feature branch and use [Atlas's schema diff capability](https://atlasgo.io/declarative/diff)
  to calculate the SQL statements that are going to be run against the database. We can then
  use [Atlas's linting capability](https://atlasgo.io/versioned/lint) to provide insights
  about possible dangers the arise from the proposed change.
* *Change visualization* - to assist reviewers in understanding the impact of changes
  proposed in a specific pull request we generate a visual diff
  (using an ERD similar to [entviz](/blog/2021/08/26/visualizing-your-data-graph-using-entviz/)) reflect
  the changes to a project's schema.
* *Schema Linting* - using the official [go/analysis](https://pkg.go.dev/golang.org/x/tools/go/analysis)
  package to create linters that analyze an Ent schema's Go code and enforce policies (such as naming
  or indexing conventions) on the schema definition level.

### Wrapping up

In this post, we presented the concept of CI and discussed ways in which it
can be practiced for Ent projects. Next, we presented CI checks we are experimenting
with internally. If you would like to see these checks become a part of Ent or have other ideas
for providing CI tools for Ent, ping us on the [Ent Discord Server](https://discord.gg/qZmPgTE6RX).

:::note For more Ent news and updates:

- Subscribe to our [Newsletter](https://entgo.substack.com/)
- Follow us on [Twitter](https://twitter.com/entgo_io)
- Join us on #ent on the [Gophers Slack](https://entgo.io/docs/slack)
- Join us on the [Ent Discord Server](https://discord.gg/qZmPgTE6RX)
:::