Remove devscripts expect the checkbashisms script, and remove lsb-release from rocker/r-ver

[eitsupi]

Close #510

ToDo

• Update the GitHub Actions workflow for testing install_R_source.sh to test rocker scripts on new rocker/r-ver. ([CI] More tests for rocker scripts #523)
• Update NEWS.md

[eitsupi]

Unfortunately, the image built from 4a1df66 does not appear to have reduced image size (rocker/r-ver:devel 856MB to 856MB) 🤔

[eitsupi]

Perhaps we need to rethink the minimum package requirements: python3 will be installed even if devscripts is not installed (listed below).

rocker-versioned2/scripts/install_R_source.sh

Lines 34 to 57 in 4a1df66

	apt-get install -y --no-install-recommends \
	bash-completion \
	ca-certificates \
	file \
	fonts-texgyre \
	g++ \
	gfortran \
	gsfonts \
	libblas-dev \
	libbz2-* \
	libcurl4 \
	libicu* \
	liblapack-dev \
	libpcre2* \
	libjpeg-turbo* \
	libpangocairo-* \
	libpng16* \
	"libreadline${READLINE_VERSION}" \
	libtiff* \
	liblzma* \
	make \
	unzip \
	zip \
	zlib1g

[cboettig]

yeah, I'm still relatively skeptical that there are major savings to be had here, especially that will persist after a user also adds commonly used packages etc, at least while remaining based on Ubuntu. @gaborcsardi's Alpine based https://github.com/r-hub/r-minimal is probably a better option for environments where saving 10s of MB is critical.

[benz0li]

@eitsupi The problematic line is

rocker-versioned2/scripts/install_R_source.sh

Line 16 in 4a1df66

apt-get -y install locales lsb-release

ℹ️ lsb-release depends on python3.

[benz0li]

yeah, I'm still relatively skeptical that there are major savings to be had here

@cboettig It's not only about reducing image size, but also reducing the number of [unneeded] packages.

Installing devscripts on bare ubuntu:focal results in 104 newly installed packages.

[benz0li]

You could use UBUNTU_VERSION=$(. /etc/os-release && echo $UBUNTU_CODENAME) at

rocker-versioned2/scripts/install_R_source.sh

Line 23 in 4a1df66

UBUNTU_VERSION=$(lsb_release -sc)

instead of [installing and] using lsb_release.

[cboettig]

Thanks @benz0li , 💯 with you on trimming unnecessary dependencies. The lsb_release is a good example.

Having unneeded packages increases image size and maybe makes a bigger surface area of dependencies that could break later, as well as potential security issues. Though for the latter two issues I think relying on the official ubuntu LTS repo sources is probably a better way to avoid either security or dependency issues than us hand-rolling dependencies. I like both of the above work-arounds because it looks like they will still be based on the official repo sources, where we benefit from the dependency management and security patching of the Debian and Canonical maintainers.

[eitsupi]

I've been writing shell scripts as Dev Container Features for these days and I've learned how good the method of loading os-release scripts is.
https://github.com/rocker-org/devcontainer-features/blob/cbee3bfdce891012e88ae87c0da2c925a6a11301/src/r-apt/install.sh#L34
https://github.com/rocker-org/devcontainer-features/blob/cbee3bfdce891012e88ae87c0da2c925a6a11301/src/r-apt/install.sh#L123-L129
Definitely a good thing to bring this here.

[eitsupi]

The size of rocker/r-ver:devel was reduced from 836MB (bfe2d71) -> 808MB (c5a1e36) by deleting lsb-release.
However, lsb-release is a dependency of RStudio Server, so it seems that rocker/rstudio needs to be lsb-release installed.

And, Python 3 continues to be installed. I do not know where this came from.

Edit: I was mistaken. The following apt packages have been removed. Thanks @benz0li !

distro-info-data	0.52ubuntu0.2
libmpdec3	2.5.1-2build2
libpython3-stdlib	3.10.6-1~22.04
libpython3.10-stdlib	3.10.6-1~22.04.1
libsqlite3-0	3.37.2-2
lsb-release	11.1.0ubuntu4
python3-minimal	3.10.6-1~22.04
python3.10	3.10.6-1~22.04.1