Add a line to a dockerfile and update metadata

Adds a line to a dockerfile and updates its metadata based on the instruction. This is an internal function used by the more specific dfi_* functions.

Usage

add_dockerfile_line(dockerfile, instruction, args)

Arguments

dockerfile

A dockerfile object

instruction

Docker instruction (e.g., "FROM", "RUN")

args

Arguments for the instruction

Value

Updated dockerfile object with the new line and updated metadata

Details

This internal function handles:

• Adding the instruction with proper formatting

• Handling multi-line arguments with appropriate indentation

• Updating metadata for special instructions like FROM

For FROM instructions, it extracts and stores:

• Base image name

• Package manager

• Operating system

• R version (for rocker/r-ver:version images)

See also

dfi_from() for adding a FROM instruction & dfi_run() for adding a RUN instruction

Other dockerfile core functions: check_dockerfile(), dockerfile(), is_dockerfile(), print.dockerfile()