Compose File Reference: Volumes - Long Syntax, Options, and `volumes

> with named volumes, relative paths should always begin with `.` or `..`. > [!NOTE] > > For bind mounts, the short syntax creates a directory at the source path on the host if it doesn't exist. This is for backward compatibility with `docker-compose` legacy. > It can be prevented by using long syntax and setting `create_host_path` to `false`. #### Long syntax The long form syntax lets you configure additional fields that can't be expressed in the short form. - `type`: The mount type. Either `volume`, `bind`, `tmpfs`, `image`, `npipe`, or `cluster` - `source`: The source of the mount, a path on the host for a bind mount, a Docker image reference for an image mount, or the name of a volume defined in the [top-level `volumes` key](volumes.md). Not applicable for a tmpfs mount. - `target`: The path in the container where the volume is mounted. - `read_only`: Flag to set the volume as read-only. - `bind`: Used to configure additional bind options: - `propagation`: The propagation mode used for the bind. - `create_host_path`: Creates a directory at the source path on host if there is nothing present. Defaults to `true`. - `selinux`: The SELinux re-labeling option `z` (shared) or `Z` (private) - `volume`: Configures additional volume options: - `nocopy`: Flag to disable copying of data from a container when a volume is created. - `subpath`: Path inside a volume to mount instead of the volume root. - `tmpfs`: Configures additional tmpfs options: - `size`: The size for the tmpfs mount in bytes (either numeric or as bytes unit). - `mode`: The file mode for the tmpfs mount as Unix permission bits as an octal number. Introduced in Docker Compose version [2.14.0](/manuals/compose/releases/release-notes.md#2260). - `image`: Configures additional image options: - `subpath`: Path inside the source image to mount instead of the image root. Available in [Docker Compose version 2.35.0](/manuals/compose/releases/release-notes.md#2350) - `consistency`: The consistency requirements of the mount. Available values are platform specific. > [!TIP] > > Working with large repositories or monorepos, or with virtual file systems that are no longer scaling with your codebase? > Compose now takes advantage of [Synchronized file shares](/manuals/desktop/features/synchronized-file-sharing.md) and automatically creates file shares for bind mounts. > Ensure you're signed in to Docker with a paid subscription and have enabled both **Access experimental features** and **Manage Synchronized file shares with Compose** in Docker Desktop's settings. ### `volumes_from` `volumes_from` mounts all of the volumes from another service or container. You can optionally specify read-only access `ro` or read-write `rw`. If no access level is specified, then read-write access is used. You can also mount volumes from a container that is not managed by Compose by using the `container:` prefix. ```yaml volumes_from: - service_name - service_name:ro - container:container_name - container:container_name:rw ``` ### `working_dir` `working_dir` overrides the container's working directory which is specified by the image, for example Dockerfile's `WORKDIR`.

This section elaborates on the long syntax for defining volumes in a Compose file, detailing options for `type`, `source`, `target`, `read_only`, `bind` (including `propagation`, `create_host_path`, and `selinux`), `volume` (including `nocopy` and `subpath`), `tmpfs` (including `size` and `mode`), `image` (including `subpath`), and `consistency`. It also describes `volumes_from` for mounting volumes from other services or containers and `working_dir` for overriding the container's working directory.