# Parameter

> customize docker with 8-parameter
---

There are **8** parameters for the Docker module:

| Name                                                                    | Type       | Level | Comment                                                   |
|-------------------------------------------------------------------------|------------|-------|-----------------------------------------------------------|
| [`docker_enabled`](/docs/docker/param#docker_enabled)                   | `bool`     | G/C/I | enable docker on this node?                               |
| [`docker_data`](/docs/docker/param#docker_data)                         | `path`     | G/C/I | Docker data directory, `/var/lib/docker` by default       |
| [`docker_storage_driver`](/docs/docker/param#docker_storage_driver)     | `enum`     | G/C/I | Docker storage driver, `overlay2` by default              |
| [`docker_cgroups_driver`](/docs/docker/param#docker_cgroups_driver)     | `enum`     | G/C/I | docker cgroup fs driver: cgroupfs,systemd                 |
| [`docker_registry_mirrors`](/docs/docker/param#docker_registry_mirrors) | `string[]` | G/C/I | docker registry mirror list                               |
| [`docker_exporter_port`](/docs/docker/param#docker_exporter_port)       | `port`     | G     | Docker metrics exporter port, `9323` by default           |
| [`docker_image`](/docs/docker/param#docker_image)                       | `path[]`   | G/C/I | docker image to be pulled, [] by default                  |
| [`docker_image_cache`](/docs/docker/param#docker_image_cache)           | `path`     | G/C/I | docker image cache tarball glob, `/tmp/docker` by default |

------

## Defaults

Docker’s default parameters are defined in [`roles/docker/defaults/main.yml`](https://github.com/pgsty/pigsty/blob/v3.7.0/roles/docker/defaults/main.yml)

```yaml
docker_enabled: false             # enable docker on this node?
docker_data: /var/lib/docker      # docker data directory, /var/lib/docker by default
docker_storage_driver: overlay2   # docker storage driver, can be zfs, btrfs
docker_cgroups_driver: systemd    # docker cgroup fs driver: cgroupfs,systemd
docker_registry_mirrors: []       # docker registry mirror list
docker_exporter_port: 9323        # docker metrics exporter port, 9323 by default
docker_image: []                  # docker image to be pulled after bootstrap
docker_image_cache: /tmp/docker/*.tgz # docker image cache glob pattern
```

------

## `docker_enabled`

name: `docker_enabled`, type: `bool`, level: `G/C/I`

enable docker on this node? default value is `false`

------

## `docker_data`

name: `docker_data`, type: `path`, level: `C`

Docker data directory, `/var/lib/docker` by default.

------

## `docker_storage_driver`

name: `docker_storage_driver`, type: `enum`, level: `C`

Docker storage driver, `overlay2` by default.

Please refer to: https://docs.docker.com/engine/storage/drivers/select-storage-driver/

- `overlay2`
- `fuse-overlayfs`
- `brtfs`
- `zfs`
- `vfs`



------

## `docker_cgroups_driver`

name: `docker_cgroups_driver`, type: `enum`, level: `G/C/I`

docker cgroup fs driver, could be `cgroupfs` or `systemd`, default values: `systemd`




------

## `docker_registry_mirrors`

name: `docker_registry_mirrors`, type: `string[]`, level: `G/C/I`

docker registry mirror list, default values: `[]`, Example:

Here are some examples of using the internal network image of each cloud vendor:

```yaml
["https://docker.m.daocloud.io"]                # domestic DaoCloud image site
["https://docker.1ms.run"]                      # domestic millisecond image site
["https://mirror.ccs.tencentyun.com"]           # tencent cloud intranet image site
["https://registry.cn-hangzhou.aliyuncs.com"]   # aliyun cloud intranet image site, login required
```

Consider using Cloudflare Worker [Docker Proxy](https://github.com/cmliu/CF-Workers-docker.io)

If the pull speed is too slow, you can also consider: `docker login quay.io` use other Registry.




------

## `docker_exporter_port`

name: `docker_exporter_port`, type: `port`, level: `G`

Docker metrics exporter port, `9323` by default.



------

## `docker_image`

name: `docker_image`, type: `string[]`, level: `G/C/I`

docker image to be pulled, `[]` by default

The Image listed here will be pulled during docker provisioning.



------

## `docker_image_cache`

name: `docker_image_cache`, type: `path`, level: `G/C/I`

docker image cache tarball glob list, `"/tmp/docker/*.tgz"` by default.

The local docker image cache with `.tgz` suffix match this glob list will be loaded into docker one by one:

```bash
cat *.tgz | gzip -d -c - | docker load
```