Add a FROM instruction to a dockerfile

Adds a FROM instruction to specify the base image for the Docker build. This is typically the first instruction in a Dockerfile.

Usage

dfi_from(dockerfile, image, as = NULL)

Arguments

dockerfile

A dockerfile object

image

Base image name (e.g., "rocker/r-ver:4.4.0")

as

Name for this build stage (optional, for multi-stage builds)

Value

An updated dockerfile object with the FROM instruction added

Details

The FROM instruction initializes a new build stage and sets the base image. The metadata for the dockerfile object (package manager, OS, and R version) is automatically updated based on the base image.

See also

dockerfile() for creating a dockerfile object, dfi_run() for adding commands to run in the container, & Official Docker FROM documentation

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

Examples

# Use a specific R version
df <- dockerfile() |>
  dfi_from("rocker/r-ver:4.4.0")
df
#> FROM rocker/r-ver:4.4.0 

# Use a multi-stage build
df <- dockerfile() |>
  dfi_from("rocker/r-ver:4.4.0", as = "build")
df
#> FROM rocker/r-ver:4.4.0 AS build