Mounts

Application containers run read-only by design. Mounts give you the writable, persistent storage your app needs — upload directories, generated files, caches — that survive restarts and re-deploys. You declare them in the optional <mounts> element.

<mounts>

<mounts> contains one or more <mount> elements.

<mounts>
    <mount name="storage" source="local" path="storage" clone-from-parent="true"/>
</mounts>

<mount>

Attribute	Required	Default	Description
name	Yes	—	Unique mount name within the application. Used to derive the volume name.
source	Yes	—	Backing storage: local or service.
path	Yes	—	Mount path inside the container. Relative paths are prefixed with /app/.
clone-from-parent	No	true	When creating a new branch environment, copy the mount's contents from the parent env.

Name pattern

name must match [a-zA-Z][a-zA-Z0-9 _-]* and be unique among the application's mounts.

source: local vs. service

• local — a local disk volume on the host. Best for per-environment data that lives next to the container.
• service — shared object storage. Use for data that should be available across environments or backed by a storage service.

path

The path is where the volume is mounted inside the container. An absolute path is used as-is; a relative path like storage is prefixed with /app/, becoming /app/storage.

clone-from-parent

When you push a new branch, Tragwerk creates a fresh environment. With clone-from-parent="true" (the default), the new environment's mount is seeded with a copy of the parent environment's mount data — handy for getting a realistic preview environment. Set it to false to start the mount empty.

Resulting Docker Compose effect

Each mount becomes a named Docker volume {appSlug}-{mountSlug}, mounted into the container at the resolved path. For an app app with a mount storage, the volume is app-storage mounted at /app/storage. The same volumes are attached to the app's workers and cron sidecar so they share the storage.

<application name="app" type="php:8.5" root="/">
    <web>
        <location path="/" root="public" index="index.php" passthru="/index.php"/>
    </web>
    <mounts>
        <mount name="storage" source="local" path="storage" clone-from-parent="true"/>
        <mount name="uploads" source="service" path="/app/var/uploads"/>
    </mounts>
</application>

Related

• Hooks — deploy hooks can write to mounts while the app dir is read-only
• Environments — how branch environments are created
• Examples