target "app-release" {
  inherits = ["app-dev", "_release"]
  platforms = ["linux/amd64", "linux/arm64"]
}
```

When inheriting attributes from multiple targets and there's a conflict,
the target that appears last in the `inherits` list takes precedence.
The previous example defines the `BUILDX_EXPERIMENTAL` argument twice for the `app-release` target.
It resolves to `0` because the `_release` target appears last in the inheritance chain:

```console
$ docker buildx bake --print app-release
[+] Building 0.0s (0/0)
{
  "group": {
    "default": {
      "targets": [
        "app-release"
      ]
    }
  },
  "target": {
    "app-release": {
      "context": ".",
      "dockerfile": "app.Dockerfile",
      "args": {
        "BUILDKIT_CONTEXT_KEEP_GIT_DIR": "1",
        "BUILDX_EXPERIMENTAL": "0",
        "GO_VERSION": "1.20"
      },
      "labels": {
        "org.opencontainers.image.source": "https://github.com/username/myapp"
      },
      "tags": [
        "docker.io/username/myapp"
      ],
      "platforms": [
        "linux/amd64",
        "linux/arm64"
      ]
    }
  }
}
```

### `target.labels`

Assigns image labels to the build.
This is the same as the `--label` flag for `docker build`.

```hcl
target "default" {
  labels = {
    "org.opencontainers.image.source" = "https://github.com/username/myapp"
    "com.docker.image.source.entrypoint" = "Dockerfile"
  }
}
```

It's possible to use a `null` value for labels.
If you do, the builder uses the label value specified in the Dockerfile.

### `target.matrix`

A matrix strategy lets you fork a single target into multiple different
variants, based on parameters that you specify.
This works in a similar way to [Matrix strategies for GitHub Actions].
You can use this to reduce duplication in your bake definition.

The `matrix` attribute is a map of parameter names to lists of values.
Bake builds each possible combination of values as a separate target.

Each generated target **must** have a unique name.
To specify how target names should resolve, use the `name` attribute.

The following example resolves the `app` target to `app-foo` and `app-bar`.
It also uses the matrix value to define the [target build stage](#targettarget).

```hcl
target "app" {
  name = "app-${tgt}"
  matrix = {
    tgt = ["foo", "bar"]
  }
  target = tgt
}
```

```console
$ docker buildx bake --print app
[+] Building 0.0s (0/0)
{
  "group": {
    "app": {
      "targets": [
        "app-foo",
        "app-bar"
      ]
    },
    "default": {
      "targets": [
        "app"
      ]
    }
  },
  "target": {
    "app-bar": {
      "context": ".",
      "dockerfile": "Dockerfile",
      "target": "bar"
    },
    "app-foo": {
      "context": ".",
      "dockerfile": "Dockerfile",
      "target": "foo"
    }
  }
}
```

#### Multiple axes

You can specify multiple keys in your matrix to fork a target on multiple axes.
When using multiple matrix keys, Bake builds every possible variant.

The following example builds four targets:

- `app-foo-1-0`
- `app-foo-2-0`
- `app-bar-1-0`
- `app-bar-2-0`

```hcl
target "app" {
  name = "app-${tgt}-${replace(version, ".", "-")}"
  matrix = {
    tgt = ["foo", "bar"]
    version = ["1.0", "2.0"]
  }
  target = tgt
  args = {
    VERSION = version
  }
}
```

#### Multiple values per matrix target

If you want to differentiate the matrix on more than just a single value,
you can use maps as matrix values. Bake creates a target for each map,
and you can access the nested values using dot notation.

The following example builds two targets:

- `app-foo-1-0`
- `app-bar-2-0`

```hcl
target "app" {
  name = "app-${item.tgt}-${replace(item.version, ".", "-")}"
  matrix = {
    item = [
      {
        tgt = "foo"
        version = "1.0"
      },
      {
        tgt = "bar"
        version = "2.0"
      }
    ]
  }
  target = item.tgt
  args = {
    VERSION = item.version
  }
}
```

### `target.name`

Specify name resolution for targets that use a matrix strategy.
The following example resolves the `app` target to `app-foo` and `app-bar`.