When `attach` is defined and set to `false` Compose does not collect service logs,
until you explicitly request it to.

The default service configuration is `attach: true`.

### `build`

`build` specifies the build configuration for creating a container image from source, as defined in the [Compose Build Specification](build.md).

### `blkio_config`

`blkio_config` defines a set of configuration options to set block I/O limits for a service.

```yml
services:
  foo:
    image: busybox
    blkio_config:
       weight: 300
       weight_device:
         - path: /dev/sda
           weight: 400
       device_read_bps:
         - path: /dev/sdb
           rate: '12mb'
       device_read_iops:
         - path: /dev/sdb
           rate: 120
       device_write_bps:
         - path: /dev/sdb
           rate: '1024k'
       device_write_iops:
         - path: /dev/sdb
           rate: 30
```

#### `device_read_bps`, `device_write_bps`

Set a limit in bytes per second for read / write operations on a given device.
Each item in the list must have two keys:

- `path`: Defines the symbolic path to the affected device.
- `rate`: Either as an integer value representing the number of bytes or as a string expressing a byte value.

#### `device_read_iops`, `device_write_iops`

Set a limit in operations per second for read / write operations on a given device.
Each item in the list must have two keys:

- `path`: Defines the symbolic path to the affected device.
- `rate`: As an integer value representing the permitted number of operations per second.

#### `weight`

Modify the proportion of bandwidth allocated to a service relative to other services.
Takes an integer value between 10 and 1000, with 500 being the default.

#### `weight_device`

Fine-tune bandwidth allocation by device. Each item in the list must have two keys:

- `path`: Defines the symbolic path to the affected device.
- `weight`: An integer value between 10 and 1000.

### `cpu_count`

`cpu_count` defines the number of usable CPUs for service container.

### `cpu_percent`

`cpu_percent` defines the usable percentage of the available CPUs.

### `cpu_shares`

`cpu_shares` defines, as integer value, a service container's relative CPU weight versus other containers.

### `cpu_period`

`cpu_period` configures CPU CFS (Completely Fair Scheduler) period when a platform is based
on Linux kernel.

### `cpu_quota`

`cpu_quota` configures CPU CFS (Completely Fair Scheduler) quota when a platform is based
on Linux kernel.

### `cpu_rt_runtime`

`cpu_rt_runtime` configures CPU allocation parameters for platforms with support for real-time scheduler. It can be either
an integer value using microseconds as unit or a [duration](extension.md#specifying-durations).

```yml
 cpu_rt_runtime: '400ms'
 cpu_rt_runtime: '95000'
```

### `cpu_rt_period`

`cpu_rt_period` configures CPU allocation parameters for platforms with support for real-time scheduler. It can be either
an integer value using microseconds as unit or a [duration](extension.md#specifying-durations).

```yml
 cpu_rt_period: '1400us'
 cpu_rt_period: '11000'
```

### `cpus`

`cpus` define the number of (potentially virtual) CPUs to allocate to service containers. This is a fractional number.
`0.000` means no limit.

When set, `cpus` must be consistent with the `cpus` attribute in the [Deploy Specification](deploy.md#cpus).

### `cpuset`

`cpuset` defines the explicit CPUs in which to permit execution. Can be a range `0-3` or a list `0,1`

### `cap_add`

`cap_add` specifies additional container [capabilities](https://man7.org/linux/man-pages/man7/capabilities.7.html)
as strings.

```yaml
cap_add:
  - ALL
```

### `cap_drop`

`cap_drop` specifies container [capabilities](https://man7.org/linux/man-pages/man7/capabilities.7.html) to drop
as strings.

```yaml
cap_drop:
  - NET_ADMIN
  - SYS_ADMIN
```

### `cgroup`

{{< summary-bar feature_name="Compose cgroup" >}}

`cgroup` specifies the cgroup namespace to join. When unset, it is the container runtime's decision to