Storage And Mounts

Use storage: for the fixed logical directories and mount: for everything else.

Fixed Storage Keys

stage_2:
  storage:
    app:
      type: image
    data:
      type: auto-volume
    workspace:
      type: host
      host_path: /srv/project

Those keys back:

• /soft/app
• /soft/data
• /soft/workspace

Extra Mounts

mount:
  home_dev:
    type: auto-volume
    dst_path: /home/dev

Every mount entry must set an absolute dst_path.

Switching Strategies

Common transitions:

• host during active development, image or auto-volume later
• auto-volume for state you want to keep but do not need to inspect on the host
• manual-volume when another service already owns the volume lifecycle

Path Relationships

• /hard/image/<key> is the in-image location.
• /hard/volume/<key> is the mounted location when a volume or host bind is used.
• /soft/<key> is the stable path your software should use.

Stage Rule

storage: is stage-2 only. mount: works in both stages, but runtime-only mounts are still not available during stage-2 build hooks.

See 03 Host Mount and 04 Docker Volume.