Add a VOLUME instruction to a dockerfile — dfi_volume • dockitect

Adds a VOLUME instruction to create a mount point with the specified name and mark it as holding externally mounted volumes.

Usage

dfi_volume(dockerfile, paths)

Arguments

dockerfile: A dockerfile object
paths: Path(s) to create as volumes

Value

An updated dockerfile object with the VOLUME instruction added

Details

The VOLUME instruction creates a mount point and marks it as being externally mounted. This is useful for:

Persistent data that should survive container restarts
Data you want to share between containers
Data you want to access from the host

Note that the actual binding of host directories happens at runtime using the -v flag with docker run, not during the image build.

See also

dk_template_base() for a template that sets up common volume patterns & Official Docker VOLUME documentation

Other dockerfile instruction functions: dfi_add(), dfi_arg(), dfi_cmd(), dfi_copy(), dfi_entrypoint(), dfi_env(), dfi_expose(), dfi_from(), dfi_healthcheck(), dfi_label(), dfi_maintainer(), dfi_onbuild(), dfi_run(), dfi_shell(), dfi_stopsignal(), dfi_user(), dfi_workdir()

Examples

# Create a single volume
df <- dockerfile() |>
  dfi_from("rocker/r-ver:4.4.0") |>
  dfi_volume("/data")
df 
#> FROM rocker/r-ver:4.4.0
#> VOLUME /data 
   
# Create multiple volumes
df <- dockerfile() |>
  dfi_from("rocker/r-ver:4.4.0") |>
  dfi_volume(c("/data", "/output", "/config"))
df
#> FROM rocker/r-ver:4.4.0
#> VOLUME ["/data","/output","/config"]