Storage backends

What this is about

CDMS does not store the content of files in the database, but in a file storage. Which one that is, is called the storage backend. You choose it in the hub on the system, field Storage:

• FILESYSTEM: the contents live in a directory of the server, in a container on a mounted volume.
• NONE: the application has no file storage.

A separate module brings the file storage into the application: cdms-localfs-storage. With NONE this module is missing.

The variants

See also The project scaffold.

Configuring the base directory

codamai:
  cdms:
    persistence:
      file:
        basePath: ${CODAMAI_CDMS_PERSISTENCE_FILE_BASE_PATH:/files/}

env:
  - name: CODAMAI_CDMS_PERSISTENCE_FILE_BASE_PATH
    value: /data/files/
volumeMounts:
  - name: cdms-files
    mountPath: /data/files

You set the operating mode (SINGLE or MULTI) for the whole installation. It applies to database and file storage alike and decides whether tenants get directories of their own. See SINGLE and MULTI across both modules.

The check at startup

CDMS deliberately does not create the base directory itself. If the volume were not mounted, the application would otherwise write into the container’s own file system and lose all files at the next restart, while the records stay in the database.

During operation

If the Actuator is included, the health check reports an entry storageRoot: writable as long as the base directory is writable, otherwise DOWN with the reason. That way a lost volume is noticed before users notice it.

Pitfalls

What comes next

• How the files lie in the storage: Storage layout and tenant isolation in storage
• What a file model is: What a file model is
• How large files may be: Size limits