Just-in-time file mounts

Mount files on your running Docker containers.

Using Release's just-in-time file mounts, you can mount small files as volumes on your containers.

To view or change your just-in-time file mounts, navigate to App Settings, scroll down to Advanced Settings, and click on Just-in-time file mounts.

When to use Just-in-time file mounts

This is a useful way to add application-wide configuration to instances at runtime, or to add small data files to your containers, without the need to check these files into your repository.

Just-in-time file mounts can be used to replace volume mounts that map configuration files from a host to a container in a docker-compose file.

How to add a just-in-time file mount

1. Go to Settings in your application.

2. Click on File Mounts.

3. Enter the location to mount the file in your container. e.g., /app/data/.

4. Select the file from your computer by clicking on Choose File.

5. Select at least one service from the list. The file will be mounted in selected services' containers.

6. Optional: Select "Mark as Secret" to hide the file's contents in Release's UI.

7. Click Create File Mount to add your file mount.

How to add a just-in-time file mount

The Create File Mount button is enabled only once you've entered a mount path, selected a file, and selected at least one service.

Just-in-time file mounts are limited to 1 MB each. For anything bigger, consider using volumes or Release's instant datasets.

New just-in-time file mounts will not be mounted on existing environments, and are only added to new environments. To apply your new file mount to an existing environment, delete and recreate the environment.

How to change a just-in-time file mount

Uploaded just-in-time file mounts are immutable. To change a mounted file, delete the file and upload a new one.

When you change a just-in-time file mount that is already mounted on a running container, the mounted file will not be updated until the container is redeployed.

How to delete a just-in-time file mount

Click the delete icon next to the file you want to delete.

How to view the contents of a just-in-time file mount

If the file mount has not been marked as secret, you can view its data by clicking the View button next to the file.

If the file mount has been marked as secret, the View button will be disabled.

How Release implements just-in-time file mounts

Release creates a Kubernetes ConfigMap to mount just-in-time file mounts as volumes on your containers just as they start up.