guix: pack: Add '--entry-point-argument' option.

* guix/scripts/pack.scm:
(entry-point-argument-spec-option-parser): New procedure.
(docker-image, %default-options, %docker-format-options,
show-docker-format-options/detailed, %options, show-docker-format-options,
guix-pack): Handle '--entry-point-argument' option.
* doc/guix.texi: (Invoking guix pack): Document this

Signed-off-by: Oleg Pykhalov <go.wigust@gmail.com>
Change-Id: I1124feff6af39dcc63c85fd6cc7ad50f398489dc

1 files changed, 13 insertions, 1 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index fc18deb85b..27ebed137d 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -122,6 +122,7 @@ Copyright @copyright{} 2023 Felix Lechner@*
 Copyright @copyright{} 2023 Foundation Devices, Inc.@*
 Copyright @copyright{} 2023 Thomas Ieong@*
 Copyright @copyright{} 2023 Saku Laesvuori@*
+Copyright @copyright{} 2023 Graham James Addis@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -7406,7 +7407,7 @@ execution engines listed above by setting the
 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
 @end quotation
 
-@cindex entry point, for Docker images
+@cindex entry point, for Docker and Singularity images
 @item --entry-point=@var{command}
 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
@@ -7429,6 +7430,17 @@ docker load -i pack.tar.gz
 docker run @var{image-id}
 @end example
 
+@cindex entry point arguments, for docker images
+@item --entry-point-argument=@var{command}
+@itemx -A @var{command}
+Use @var{command} as an argument to @dfn{entry point} of the resulting pack.
+This option is only valid in conjunction with @code{--entry-point} and can
+appear multiple times on the command line.
+
+@example
+guix pack -f docker --entry-point=bin/guile --entry-point-argument="--help" guile
+@end example
+
 @item --expression=@var{expr}
 @itemx -e @var{expr}
 Consider the package @var{expr} evaluates to.