---
title: Overriding configurations
description: Learn how to override configurations in Bake files to build with different attributes.
keywords: build, buildx, bake, buildkit, hcl, json, overrides, configuration
aliases:
  - /build/bake/configuring-build/
---

Bake supports loading build definitions from files, but sometimes you need even
more flexibility to configure these definitions. For example, you might want to
override an attribute when building in a particular environment or for a
specific target.

The following list of attributes can be overridden:

- `args`
- `attest`
- `cache-from`
- `cache-to`
- `context`
- `contexts`
- `dockerfile`
- `entitlements`
- `labels`
- `network`
- `no-cache`
- `output`
- `platform`
- `pull`
- `secrets`
- `ssh`
- `tags`
- `target`

To override these attributes, you can use the following methods:

- [File overrides](#file-overrides)
- [CLI overrides](#command-line)
- [Environment variable overrides](#environment-variables)

## File overrides

You can load multiple Bake files that define build configurations for your
targets. This is useful when you want to separate configurations into different
files for better organization, or to conditionally override configurations
based on which files are loaded.

### Default file lookup

You can use the `--file` or `-f` flag to specify which files to load.
If you don't specify any files, Bake will use the following lookup order:

1. `compose.yaml`
2. `compose.yml`
3. `docker-compose.yml`
4. `docker-compose.yaml`
5. `docker-bake.json`
6. `docker-bake.hcl`
7. `docker-bake.override.json`
8. `docker-bake.override.hcl`

If more than one Bake file is found, all files are loaded and merged into a
single definition. Files are merged according to the lookup order.

```console
$ docker buildx bake --print
[+] Building 0.0s (1/1) FINISHED                                                                                                                                                                                            
 => [internal] load local bake definitions                                                                                                                                                                             0.0s
 => => reading compose.yaml 45B / 45B                                                                                                                                                                                  0.0s
 => => reading docker-bake.hcl 113B / 113B                                                                                                                                                                             0.0s
 => => reading docker-bake.override.hcl 65B / 65B
```

If merged files contain duplicate attribute definitions, those definitions are
either merged or overridden by the last occurrence, depending on the attribute.

Bake will attempt to load all of the files in the order they are found. If
multiple files define the same target, attributes are either merged or
overridden. In the case of overrides, the last one loaded takes precedence.

For example, given the following files:

```hcl {title=docker-bake.hcl}
variable "TAG" {
  default = "foo"
}

target "default" {
  tags = ["username/my-app:${TAG}"]
}
```

```hcl {title=docker-bake.override.hcl}
variable "TAG" {
  default = "bar"
}
```

Since `docker-bake.override.hcl` is loaded last in the default lookup order,
the `TAG` variable is overridden with the value `bar`.

```console
$ docker buildx bake --print
{
  "target": {
    "default": {
      "context": ".",
      "dockerfile": "Dockerfile",
      "tags": ["username/my-app:bar"]
    }
  }
}
```

### Manual file overrides

You can use the `--file` flag to explicitly specify which files to load,
and use this as a way to conditionally apply override files.

For example, you can create a file that defines a set of configurations for a
specific environment, and load it only when building for that environment. The