Re: Gems and repackaging, hopefully helpful

On Sat, Oct 01, 2005 at 12:22:33AM +0900, Jim Weirich wrote:
> 
> Eivind Eklund said:
> > First of all, the comparison with a raw tar file is inappropriate.
> > Packagers basically never work with really raw tar files - we work
> > with tar files that include some installer system, be that a
> > "setup.rb" file [...]
> 
> I'm sorry, I didn't mean a tar file you just untar directly into the ruby
> directories.  I meant a tar file like the one Rake is distributed in
> (that's why I used it as an example).  The tar file contains a install
> script[1] for non-gem installs.  The gem file contains the exact same
> thing.
> 
> Gems uses the same defaults as the standard setup.rb install script uses. 
> Setting up for setup.rb makes it easy to setup for gems as well.  Using
> the rake gem packaging tools makes it trivial to distribute both gems and
> tgz file with identical contents.

And this would make the tgz quite likely to be good, and the Gem to be possible
to use some normalized tools on.  Sorry for the vague answer - I'm on a deadline
for monday and will try to get back with better answers then.  (Right now I lack
the time/calm to sit down and analyze properly.)

> > In RubyGems guarantee the Gem author that the Gem will be installed with
> > all the directories placed in a particular fashion compared to each other,
> > including extra data space.
> 
> Actually, RubyGems is entirely silent on the matter of data storage.  Thus
> the problem of individual authors doing the relative file path thing.
> 
> If RubyGems provided a option to copy files in to a area designed by
> Config::CONFIG['datadir'], would that be adequate?

I'm not sure; I have to look more closely at the present state of RubyGems.
Let me give you the info to decide for yourself, though (that will probably
help us both in the long run).  The policies that need to be possible to
follow are these (for FreeBSD; the Linux systems are similar, though not
identical.)

http://www.freebsd.org/doc/en_US.ISO8859-1/books/porters-handbook/dads-subdirs.html
http://www.freebsd.org/cgi/man.cgi?query=hier&sektion=7

The most important is being able to install binaries under $prefix/bin/,
documentation under doc/<portname>/, examples under examples/<portname>,
configuration under etc/, data under share/<portname> or similar,
put databases under /var/<suitable location>, and put man/info pages
under man/info respectively.  (Hopefully, nobody use info with a
RubyGem, though.)  Prefix is /usr/local unless the user has set it differently.

"Full" text below for convenience (I've cut down the hier manpage
to be less noisy, only containing relevant directories):

12.10 Subdirectories

Try to let the port put things in the right subdirectories of PREFIX. Some ports lump everything and put it in the subdirectory with the port's name, which is incorrect. Also, many ports put everything except binaries, header files and manual pages in the a subdirectory of lib, which does not work well with the BSD paradigm. Many of the files should be moved to one of the following: etc (setup/configuration files), libexec (executables started internally), sbin (executables for superusers/managers), info (documentation for info browser) or share (architecture independent files). See hier(7) for details; the rules governing /usr pretty much apply to /usr/local too. The exception are ports dealing with USENET ``news''. They may use PREFIX/news as a destination for their files.


hier(7):
HIER(7) 	   FreeBSD Miscellaneous Information Manual	       HIER(7)

NAME
     hier -- layout of file systems

DESCRIPTION
     A sketch of the file system hierarchy.

     /		root directory of the file system

     /usr/	contains the majority of user utilities and applications

		bin/	  common utilities, programming tools, and applica-
			  tions

		compat/   files needed to support binary compatibility with
			  other operating systems, such as Linux (created by
			  sysinstall(8))

		games/	  useful and semi-frivolous programs

		include/  standard C include files

		lib/	  shared and archive ar(1)-type libraries
			  aout/       a.out archive libraries
			  compat/     shared libraries for compatibility
				      aout/	  a.out backward compatibility
						  libraries

		libdata/  miscellaneous utility data files

		libexec/  system daemons & system utilities (executed by other
			  programs)

		local/	  local executables, libraries, etc.  Also used as the
			  default destination for the FreeBSD ports framework.
			  Within local/, the general layout sketched out by
			  hier for /usr should be used.  Exceptions are the
			  man directory (directly under local/ rather than
			  under local/share/), ports documentation (in
			  share/doc/<port>/), and /usr/local/etc (mimics
			  /etc).

		sbin/	  system daemons & system utilities (executed by
			  users)
		share/	  architecture-independent files

			  doc/	     miscellaneous documentation

			  examples/  various examples for users and program-
				     mers

			  info/      GNU Info hypertext system

			  locale/    localization files; see setlocale(3)

			  nls/	     national language support files; see
				     mklocale(1)

			  security/  data files for security policies such as
				     mac_lomac(4)
			  sendmail/  sendmail(8) configuration files
			  skel/      example . (dot) files for new accounts
			  snmp/      MIBs, example files and tree definitions
				     for the SNMP daemon.
				     defs/	 Tree definition files for use
						 with gensnmptree(1)
				     mibs/	 MIB files
		X11R6/	  X11R6 distribution executables, libraries, etc
			  (optional).
			  bin/	    X11R6 binaries (servers, utilities, local
				    packages/ports).
			  etc/	    X11R6 configuration files and scripts.
			  include/  X11R6 include files.
			  lib/	    X11R6 libraries.
			  man/	    X11R6 manual pages.
			  share/    architecture-independent files.

     /var/	multi-purpose log, temporary, transient, and spool files

		account/   system accounting files

			   acct        execution accounting file; see acct(5)

		at/	   timed command scheduling files; see at(1)
			   jobs/      directory containing job files
			   spool/     directory containing output spool files

		backups/   miscellaneous backup files

		db/	   miscellaneous automatically generated system-spe-
			   cific database files

		empty/	   empty directory for use by programs that need a
			   specifically empty directory.  Used for instance by
			   sshd(8) for privilege separation.

		log/	   miscellaneous system log files

			   wtmp        login/logout log; see wtmp(5)

		mail/	   user mailbox files

		run/	   system information files describing various info
			   about system since it was booted

			   named/      writable by the ``bind'' user; see
				       named(8)
			   ppp/        writable by the ``network'' group for
				       command connection sockets; see ppp(8)
			   utmp        database of current users; see utmp(5)

		spool/	   miscellaneous printer and mail system spooling
			   directories

			   clientmqueue/
				       undelivered submission mail queue; see
				       sendmail(8)
			   ftp/        commonly ~ftp; the anonymous ftp root
				       directory
			   mqueue/     undelivered mail queue; see sendmail(8)
			   output/     line printer spooling directories

		tmp/	   temporary files that are kept between system
			   reboots
			   vi.recover/
				       the directory where recovery files are
				       stored