Day 1 – Rocking Raku Meets Stodgy Debian

A unique method for installing Raku on Debian hosts.

Rumbling in the rack room

Santa’s IT department was now fully invested in using Raku, and it was paying off in increased programmer efficiency as well as toy output.

But old elf Eli, a system administrator, was grumbling to himself that it was a lot of work keeping the many hosts (mostly GNU/Linux, for great savings on hardware) with many different Linux flavors current given the rapid development of Raku.

He had been trying to convince his boss to gradually convert all systems to Debian, but his boss was reluctant to do so because of a conundrum: Debian has a long development cycle (good for IT stability) but Raku has a short development cycle (roughly monthly).

Systems other than Debian tended to keep Raku more current and typically stayed within 12 months of the latest Raku. But that effort often resulted in more OS maintenance than Debian required. (Note the proliferation of Linux flavors had come about due to flashy young elves, freshly out of grad school, who favored the OS-of-the-month they used in school. To Eli’s chagrin, Santa was a softy and too kind to interfere.)

Eli had long ago selected Debian as his choice of GNU/Linux systems for several reasons including its program packaging system as well as its roughly three-year upgrade cycle.

Unfortunately, that conflicted with Raku’s almost monthly upgrade cycle. Given the long cycle, Debian’s Raku version tended to be quite outdated (although usable for most purposes). Eli wanted a maintainable way to keep Raku current as well as make it a primary coding language on each new system.

The steadfast but unheralded folks on the Raku release team have provided many ways to install Raku on several flavors of GNU/Linux as well as MacOS and Windows. Eli started using the ‘rakudo-pkg’ method when it was first introduced years ago.

But, when it was announced it would not keep up with Debian versions after the end of the Long Term Support (LTS) period, he started considering other available methods to see which was best for complete automation both for regular upgrades as well as during initial Debian installations (including Debian’s preseeding installation).

Inspiration and perspiration

After considering methods published on https://rakudo.org, he decided the binary downloads looked to be the easiest.

An archive of code compiled for the desired system, accompanied by an identifying SHA-256 hash and signed by one of the holders of the public keys published on the site, and unpacked into a standard directory should be possible with Raku alone without other modules than the one he would create.

With the tantalizing smell of figgy pudding coming from the mess hall, he started to think deep thoughts while doing his regular duties. Finally, eureka! Why not use the Debian system Raku to bootstrap a current Raku—genius!

Eagerly he began to gobble pudding while coding…. After too much pudding and many code iterations, mistakes, and going down rabbit holes, and with help from fellow Debianites on the Debian users mailing list, he came up with his shiny new Raku module distribution: RakudoBin (not yet published, but available online).

He solved the bootstrap problem by using a special path setup so the new module’s installation script could use the system Raku while other existing or new Raku programs would have the latest Raku first in the default user PATH. Because of the lengths of the paths defined in the actual host system, the paths are represented here by an alias, [pathX], where ‘X’ is the path segment:

• pathA /opt/rakudo/bin:/opt/rakudo/share/perl6/site/bin
• pathB /usr/local/bin:/usr/bin:/bin
• pathC /usr/local/games:/usr/games

The final system path for all users is established by creating the following system files:

$ cat /etc/environment
pathA:pathB:pathC
$ cat /etc/profile
pathA:pathB:pathC

Standard new user files in /etc/skel are okay as they are. But a missing file is added to correct the long-standing lack of a reliable graphical login solution for path setting, at least for the Mate deskstop:

# existing files NOT modified:
/etc/skel/.bash_logout
/etc/skel/.bashrc
/etc/skel/.profile
# added, not Debian standard, solves graphical
#   login path setting problem:
$ cp /etc/skel/.profile /etc/skel/.xsessionrc

That solution was achieved with much trial and error on a new host with freshly installed Debian 12 (Bookworm), plus lots of help from fellow Debian users, and a slightly outdated Debian online document.

The latest set of Rakudo binary files for a GNU/Linux system consist of:

They are downloaded and checked for hash validity, then unpacked into directory /opt/rakudo. The paths required to use the installed binaries are /opt/rakudo/bin and /opt/rakudo/share/perl6/site/bin.

The installation script sets the standard path to put the new paths before the standard paths as shown below.

Debian standard path:

/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games

RakudoBin modified path (with game paths removed):

/opt/rakudo/bin:/opt/rakudo/share/perl6/site/bin:pathB:pathC

Note the path finds the newly installed executables before the system’s since those are under directory /usr/bin. Eli solved the bootstrap problem by putting this as the shebang line in the installation script:

#!/usr/bin/raku

One other tricky problem Eli solved, and was quite proud of, was checking for the latest version without downloading large files. The easiest method, knowing the URL and format of the file set, is to just attempt to download it with this code:

shell "curl -1sLf https://path/file -o /localpath/file";

If the file doesn’t exist, the curl command throws an error. If we can trap the error, we can say the file doesn’t exist. Thanks to the help of Nick [no, not Santa, IRC #raku’s Nick Logan, aka @ugexe]), we can do that easily with this simple line in a check-https sub returning a Bool:

sub check-https("https://path/file" --> Bool {
    try {
        so quietly shell
          "curl -1sLf https://path/file -o /localpath/file"
    } // False
}

Here’s a link for some help for a more general method for future improvements to check a partial download with large files.

The installation script, by default, carefully asks for conrirmation before proceeding with various system-modifying parts. Using the quiet option assumes all is approved and no further permissions are requested.

Party time

In summary, module RakudoBin will give system administrators a practical way to (1) have a stable Debian system and (2) upgrade their Raku version to the latest. The module will also provide an easy way to quickly convert a standard Debian installation into a standard Raku host with common paths for all new users.

Santa’s Epilogue

Don’t forget the “reason for the season:” ✝

As I always end these jottings, in the words of Charles Dickens’ Tiny Tim, “may God bless Us, Every one!” [1]

Footnotes

1. A Christmas Carol, a short story by Charles Dickens (1812-1870), a well-known and popular Victorian author whose many works include The Pickwick Papers, Oliver Twist, David Copperfield, Bleak House, Great Expectations, and A Tale of Two Cities.