lc_autolfs

scripting the lfs package installation

or scripting the lfs book package installation instructions

don't know what lfs is? then you don't know the meaning of free: https://www.linuxfromscratch.org

the problem lc_autolfs solves is when installing a base lfs system, it is easy to overlook what packages or commands have been skipped or have failed; lc_autolfs solves this problem by facilitating an automated workflow to install and review. this is accomplished primarily by mentally classiyfing the commands from the instructions pages before writing them out, writing them in their entirety before running them, and executing the commands automated in order to capture exit codes and via the script binary (from util-linux) to record the outputs. the scripts can be used as provided and are short enough to read as a poc to model your own scripts after.

USAGE VIDEO DEMOS

lc_autolfs_0_0_1.mp4

this video demonstrates (patchcmd), cmd, scmd, (tcmd), and pcmd or all expanded: (patch commands), build commands, install commands, (test commands), and post configuration commands respectively. if there were patch commands, patchcmd1,2,3 would have been used or for tests tcmd1,2,3 etc. described in detail below

autolfs_0_1_2__1.mp4

this video demonstrates the extra feature utilized by copying or linking to .bash_profile. not shown: extra shows test failures when applicable after the run.

USAGE

refer to https://www.linuxfromscratch.org/lfs/view/stable/chapter08/sysklogd.html to follow along with the examples

add script to the chroot env and clone the repo

if script is already installed in the chroot environment, the statement to copy script from the host to $LFS/sources/bin may be omitted

(host)# mount $LFS
(host)$ mkdir -p $LFS/sources/bin # this will be added to the path when sourcing later
(host)$ cp /usr/bin/script $LFS/sources/bin
(host)$ cd $LFS/sources
(host) ($LFS/sources)$ #wget tarbells
(host) ($LFS/sources)$ git clone https://github.com/krunch3r76/lc_autolfs
(host) ($LFS/sources)$ cd lc_autolfs
(host) ($LFS/sources/lc_autolfs)$ git checkout v0.1.3

if this was a pass 1 or pass 2 instruction you would change the name of the source dir and append _pass1 _pass2 etc then mklfscmd

if this was an instruction page without a source file you would create a directory with memorable name, cd, then run mklfscmd

chroot into $LFS

next chroot into $LFS as per the manual directions (mount proc as needed beforehand)

source needed environment variables and functions (e.g. mklfscmd)

(chroot) /# cd /sources/lc_autolfs
(chroot) /sources/lc_autolfs# source s_f

untar desired package (repeat for subsequent packages here)

(chroot) /sources/lc_autolfs# cd /sources
(chroot) /sources# tar -xf sysklogd-1.5.1.tar.gz
(chroot) /sources# pushd sysklogd-1.5.1
(chroot) /sources/sysklogd-1.5.1# mklfscmd
# comments: 1.copies skeleton files from cmdskeleton repo dir to corresponding /sources/cmds/<pkgname> dir
#2.creates a .cmds dir there
#3.changes directory to there (.cmds directory under /sources/cmds/<pkgname>)
(chroot) /sources/cmds/sysklogd-1.5.1/.cmds#

copy and paste instructions from lfs manual page into text files

lfs instructions may be categorized in order as patch commands, configuration/build commands, test commands, installation commands, and post-configuration commands. here in /sources/cmds/sysklod-1.5.1/.cmds we create text files for these categories to be run as shell commands prioritized in this order.

create text files that contain the instructions for patching: patchcmd{1,2,3,...}

in the sysklogd-1.5.1 manual page there are none, otherwise we would create patchcmd1,2,3 files. they may be omitted here.

create text files that contain build/configuration instructions: cmd{1,2,3...}

we will create the first command(s) to be run as a text file cmd1. if there was a patch command to run, it would be named patchcmd1 and would be run first later. as, there are not patch commands, we begin by creating a configuration/build command text file cmd1:

(chroot) /sources/cmds/sysklogd-1.5.1/.cmds# cat >cmd1
sed -i '/Error loading kernel symbols/{n;n;d}' ksym_mod.c
sed -i 's/union wait/int/' syslogd.c
^D

each command text is run in order from 1,2,3..etc. the manual page for sysklogd's next block is also a configuration/build command, so we create cmd2 to follow cmd1:

(chroot) /sources/cmds/sysklogd-1.5.1/.cmds# cat >cmd2
make
^D

create text files that contain test instructions: tcmd{1,2,3...}

there are no test commands for the example package but if there were it would follow the same pattern. they may be omitted here.

create text files that contain install instructions: scmd{1,2,3...}

the next command is an install command, typically make install. this would normally require superuser privileges. it is assumed for now that chroot is running with root privileges, however. to set the commands run as "superuser" we begin with scmd1 and then if needed scmd2 and so on to set up symbolic links etc.

(chroot) /sources/cmds/sysklogd-1.5.1/.cmds# cat >scmd1
make BINDIR=/sbin install
^D

create text files that contain system configuration instructions: pcmd{1,2,3,...}

next we see there are post configuration commands in the sysklogd manual page. these are copied into pcmd1 (pcmd2 etc if there were more blocks):

(chroot) /sources/cmds/sysklogd-1.5.1/.cmds# cat >pcmd1
cat > /etc/syslog.conf << "EOF"
# Begin /etc/syslog.conf

auth,authpriv.* -/var/log/auth.log
*.*;auth,authpriv.none -/var/log/sys.log
daemon.* -/var/log/daemon.log
kern.* -/var/log/kern.log
mail.* -/var/log/mail.log
user.* -/var/log/user.log
*.emerg *

# End /etc/syslog.conf
EOF
^D

run install script to automatically execute

(chroot) /sources/cmds/sysklogd-1.5.1/.cmds# cd ..
(chroot) /sources/cmds/sysklogd-1.5.1# ./install.sh
# comments: patchcmds, cmds, tcmds, scmds, and pcmds are run in sequence with brief pauses if interruption desirable
#, output to screen, and logged. the sequence stops if there is an error except for test commands
#(unless ignore passed to script - see options section below)

note, pressing enter to proceed to the next step is optional. the next instruction will execute after a short timeout without having to press enter each time.

after a successful run, review

/sources/cmds/sysklogd-1.5.1# less -r cmdsruns
/sources/cmds/sysklogd-1.5.1# less -r script
/sources/cmds/sysklogd-1.5.1# tail /sources/journal # chronological entries of pkgs installed (one per line)
/sources/cmds/sysklogd-1.5.1# popd
/sources#

USAGE TIPS

there is no need to manually press enter to run each command, each command will execute after a short timeout (as long as the previous did not report an error)

check the file $LFS/sources/journal to see the packages have been installed and in what order (useful to find a skipped package)

some instructions may require you to reclassify commands in an order different from that read. the categorization [:letter:]cmd is only a guideline but order is always preserved: patchcmd, cmd, tcmd, scmd, pcmd. tcmd is treated specially to ignore errors but this may not be needed anyway and test commands can be run in another category then output reviewed in the script file. if in doubt, using cmd only is okay. again, only order is important and the rest is mostly just to help divide the instructions to help the reader follow along better

to reinstall a package simply untar and run mklfscmd in the package dir. the cmds from before will be preserved and the directory will change as expected to the package cmds directory.

only source s_f once (not needed again)

edit s_f to uncomment the makeflags line to reduce build times, then source. (without an editor, this would be done via the host mount)

after setting up the build environment, it is okay to mv the cmds directory to cmds_build or whatever so that a new cmds directory is used for the next stage (to avoid package name conflicts and retain logs)

any manual page can be scripted even if there is no associated tarbell. the execution will be logged to /sources/journal under whatever directory name mklfscmd was run from.

$LFS/sources/bin might be a good place to write your own scripts, that could wrap these scripts!

options to install.sh

errors on any commands except test commands will break execution. currently, install.sh accepts a single argument which is either "ignore" or "skiptests". "ignore" will ignore all errors to proceed to the next *cmd. "skiptests" will skip running the test commands (if any were specified). more options in the future for more granularity, including skipping post configuration.

example (substitute sysklogd with whatever package)

(chroot) /sources/cmds/sysklogd-1.5.1# ./install.sh ignore
(chroot) /sources/cmds/sysklogd-1.5.1# ./install.sh skiptests

COMMENTS

as of this writing this is an MVP. over time, the interface should get less klunky and more candy.

script (part of the util-linux suite of tools) is standard on any linux distribution and the directions to copy from the host should be safely skipped if util-linux of LFS has already been compiled e.g. at: https://www.linuxfromscratch.org/lfs/view/stable/chapter07/util-linux.html.