Fcron-3.2.1

Introduction to Fcron

The Fcron package contains a periodical command scheduler which aims at replacing Vixie Cron.

This package is known to build and work properly using an LFS-10.1 platform.

Package Information

Fcron Dependencies

Optional

An MTA, text editor (default is vi from the Vim-8.2.2433 package), Linux-PAM-1.5.1, and DocBook-utils-0.6.14

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/fcron

Installation of Fcron

Fcron uses the cron facility of syslog to log all messages. Since LFS does not set up this facility in /etc/syslog.conf, it needs to be done prior to installing Fcron. This command will append the necessary line to the current /etc/syslog.conf (perform as the root user):

cat >> /etc/syslog.conf << "EOF"
# Begin fcron addition to /etc/syslog.conf

cron.* -/var/log/cron.log

# End fcron addition
EOF

The configuration file has been modified, so reloading the sysklogd daemon will activate the changes (again as the root user).

/etc/rc.d/init.d/sysklogd reload

For security reasons, an unprivileged user and group for Fcron should be created (perform as the root user):

groupadd -g 22 fcron &&
useradd -d /dev/null -c "Fcron User" -g fcron -s /bin/false -u 22 fcron

Install Fcron by running the following commands:

./configure --prefix=/usr          \
            --sysconfdir=/etc      \
            --localstatedir=/var   \
            --without-sendmail     \
            --with-boot-install=no \
            --with-systemdsystemunitdir=no &&
make

This package does not come with a test suite.

Now, as the root user:

make install

DESTDIR install must be done as root user. Furthermore, if PAM configuration files should be installed in /etc/pam.d, you have to create this directory in the DESTDIR before doing the install.

Command Explanations

--without-sendmail: By default, Fcron will attempt to use the sendmail command from an MTA package to email you the results of the fcron script. This switch is used to disable default email notification. Omit the switch to enable the default. Alternatively, you can use the --with-sendmail=</path/to/MTA command> to use a different mailer command.

--with-boot-install=no: This prevents installation of the bootscript included with the package.

--with-systemdsystemunitdir=no: This prevents building the systemd units, which are not needed for a SYS V system.

--with-editor=</path/to/editor>: This switch allows you to set the default text editor.

--with-dsssl-dir=</path/to/dsssl-stylesheets>: May be used if you have DocBook-utils-0.6.14 installed. Currently, the dsssl stylesheets are located at /usr/share/sgml/docbook/dsssl-stylesheets-1.79.

Configuring Fcron

Config Files

/etc/fcron.conf, /etc/fcron.allow, and /etc/fcron.deny

Configuration Information

There are no required changes in any of the config files. Configuration information can be found in the man page for fcron.conf.

fcron scripts are written using fcrontab. Refer to the fcrontab man page for proper parameters to address your situation.

If Linux-PAM is installed, two PAM configuration files are installed in etc/pam.d. Alternatively if etc/pam.d is not used, the installation will append two configuration sections to the existing /etc/pam.conf file. You should ensure the files match your preferences. Modify them as required to suit your needs.

Periodic Jobs

If you would like to setup a periodic hierarchy for the root user, first issue the following commands (as the root user to create the /usr/bin/run-parts script:

cat > /usr/bin/run-parts << "EOF" &&
#!/bin/sh
# run-parts:  Runs all the scripts found in a directory.
# from Slackware, by Patrick J. Volkerding with ideas borrowed
# from the Red Hat and Debian versions of this utility.

# keep going when something fails
set +e

if [ $# -lt 1 ]; then
  echo "Usage: run-parts <directory>"
  exit 1
fi

if [ ! -d $1 ]; then
  echo "Not a directory: $1"
  echo "Usage: run-parts <directory>"
  exit 1
fi

# There are several types of files that we would like to
# ignore automatically, as they are likely to be backups
# of other scripts:
IGNORE_SUFFIXES="~ ^ , .bak .new .rpmsave .rpmorig .rpmnew .swp"

# Main loop:
for SCRIPT in $1/* ; do
  # If this is not a regular file, skip it:
  if [ ! -f $SCRIPT ]; then
    continue
  fi
  # Determine if this file should be skipped by suffix:
  SKIP=false
  for SUFFIX in $IGNORE_SUFFIXES ; do
    if [ ! "$(basename $SCRIPT $SUFFIX)" = "$(basename $SCRIPT)" ]; then
      SKIP=true
      break
    fi
  done
  if [ "$SKIP" = "true" ]; then
    continue
  fi
  # If we've made it this far, then run the script if it's executable:
  if [ -x $SCRIPT ]; then
    $SCRIPT || echo "$SCRIPT failed."
  fi
done

exit 0
EOF
chmod -v 755 /usr/bin/run-parts

Next, create the directory layout for the periodic jobs (again as the root user):

install -vdm754 /etc/cron.{hourly,daily,weekly,monthly}

Finally, add the run-parts to the system fcrontab (while still the root user):

cat > /var/spool/fcron/systab.orig << "EOF"
&bootrun 01 * * * * root run-parts /etc/cron.hourly
&bootrun 02 4 * * * root run-parts /etc/cron.daily
&bootrun 22 4 * * 0 root run-parts /etc/cron.weekly
&bootrun 42 4 1 * * root run-parts /etc/cron.monthly
EOF

Boot Script

Install the /etc/rc.d/init.d/fcron init script from the blfs-bootscripts-20210110 package.

make install-fcron

Finally, again as the root user, start fcron and generate the /var/spool/fcron/systab file:

/etc/rc.d/init.d/fcron start &&
fcrontab -z -u systab

Contents

Installed Programs: fcron, fcrondyn, fcronsighup, and fcrontab
Installed Libraries: None
Installed Directories: /usr/share/doc/fcron-3.2.1 and /var/spool/fcron

Short Descriptions

fcron

is the scheduling daemon

fcrondyn

is a user tool intended to interact with a running fcron daemon

fcronsighup

instructs fcron to reread the Fcron tables

fcrontab

is a program used to install, edit, list and remove the tables used by fcron

Last updated on 2021-02-20 11:35:58 -0800