SYSLOG option in lts.conf not documented

[Imre Gergely]

I was looking for a way to _disable_ remote logging on the thin clients. There's an ltsp.conf file generated on the client at boot, which sends logs to $SERVER by default:

root@ltsp1:~# cat /etc/rsyslog.d/ltsp.conf
*.* @192.168.0.254

There is code to disable this in /opt/ltsp/i386/usr/share/ltsp/ltsp-init-common around line 300:

configure_syslog() {
    if [ -z "$SYSLOG" ] || [ "$SYSLOG" = "remote" ]; then
        syslog_conf=/etc/syslog.conf
        if [ -d /etc/rsyslog.d ]; then
            syslog_conf=/etc/rsyslog.d/ltsp.conf
            touch $syslog_conf
        fi
        if [ -f "$syslog_conf" ]; then
            cat <<EOF > "$syslog_conf"
*.* @${SYSLOG_HOST:-$SERVER}
EOF
        fi
    fi
}

This SYSLOG option does not appear in the documentation (man 5 lts.conf). It should be added if it's not a hack (and I don't see why it would be).

[Wim Muskee (wimmuskee)]

Current behaviour of configure_syslog() seems a little weird, shouldn't it just be SYSLOG=true or false ? Or replace SYSLOG by SYSLOG_REMOTE=true or false, to make the option clearer?

[Alkis Georgopoulos (alkisg)]

Maybe the following line could be changed in the code:

- if [ -z "$SYSLOG" ] || [ "$SYSLOG" = "remote" ]; then
+ if [ "${SYSLOG_HOST-localhost}" != "localhost" ]; then

The weird ${SYSLOG_HOST-localhost} syntax means "if SYSLOG_HOST is set, but empty, then return the string localhost".
So to disable remote logging, one of the following could be used in lts.conf:

SYSLOG_HOST=""
or
SYSLOG_HOST="localhost"

Then there wouldn't be any need to introduce a new variable named "SYSLOG".

[Alkis Georgopoulos (alkisg)]

Another problem is that the default configuration file name is defined in the configure_syslog() function as:
syslog_conf=/etc/rsyslog.d/ltsp.conf

That, in Ubuntu, doesn't override the defaults in /etc/rsyslog.d/50-default.conf, so by default LTSP clients log locally, not on the server, contrary to what the man page says about SYSLOG_HOST.

So a second change is needed:
- syslog_conf=/etc/rsyslog.d/ltsp.conf
+ syslog_conf=/etc/rsyslog.d/90-ltsp.conf

[Xavier Brochard (xavier)]

To complete Alkis point: as one need to setup also the server rsyslog.conf, I don't see why default SYSLOG is true.

[Wim Muskee (wimmuskee)]

Agreed with alkisg.

[Wim Muskee (wimmuskee)]

Committed: Defaulted local syslog, define SYSLOG_HOST in lts.conf for remote logging.

[Alkis Georgopoulos (alkisg)]

Fix released in LTSP 5.4.1.

[Launchpad Janitor (janitor)]

This bug was fixed in the package ltsp - 5.4.2-2ubuntu1

---------------
ltsp (5.4.2-2ubuntu1) quantal; urgency=low

  * Merging from Debian. Remaining changes:
    - Include dhcpd.conf configuration using 192.168.0.1/24 instead of upstream
      192.168.67.0/24 (until we deal with upgrades properly)
    - X-Ubuntu-Depends entries to keep similar package list as pre-merge
    - Change debian/watch to monitor Debian instead of Ubuntu
    - Include ltsp-cluster in ltsp-client-core
    - Include ltsp-open in ltsp-client-core
    - Set ltsp-client-builder/ltsp_update_image to true by default
    - Set ltsp-client-builder/configure_network_interface to true by default
    - Add ltsp-client-builder/fat-client
    - Setup Edubuntu LTSP in ltsp-server.postinst

ltsp (5.4.2-2) unstable; urgency=low

  * ltsp-server: Move lts.conf from doc to doc/examples.

ltsp (5.4.2-1) unstable; urgency=low

  * New upstream version:
    - init-ltsp.d: regenerate dbus machine-id.
    - Allow regular printer sharing via CUPS.
    - Split common-server.conf to ltsp-server.conf and ltsp-client.conf.

  * Install update-kernels.conf from debian/rules to handle differences in
    Ubuntu and Debian.

ltsp (5.4.1-1) unstable; urgency=low

  * New upstream version:
    - Rewrite kiosk screen script and corresponding plugin handling to create
      ltspkiosk user and dirs at runtime.
    - Only use X_SMART_COLOR_DEPTH if X_COLOR_DEPTH is unset.
    - When DNS_SERVER is unset, try to locate one.
    - Default local syslog, define SYSLOG_HOST in lts.conf for remote logging.
      (LP: #697387)
    - Improvements to update-kernels:
      + Default to a versioned kernel boot entry rather than a symlinked one.
      + Create a sub-menu for all available kernel versions and variants.
      + Option to use syslinux ifcpu64.c32 to select an appropriate 64-bit, PAE
        or 32-bit kernel at boot.
      + Generate boot menu entries for both NFS and NBD.
      + Add yaboot entries for all kernel versions and boot methods.
    - ltsp-common-functions: Implement /etc/ltsp/*.conf.d include dirs.
    - ltsp-update-sshkeys: Do not fail if /etc/ssh/ssh_host_*_key.pub
      doesn't exist.
    - ltsp-server-dnsmasq.conf example: increase DHCP lease to 8h.
    - Fix TIMESERVER support in init-ltsp.d hook.
    - Ensure $HOME is set in xfreerdp screen script, working around an
      xfreerdp segfault.

  * ltsp-client-core: Install a default update-kernels.conf.
  * Implement substvars mechanism to account for differences in Debian and
    Ubuntu packaging.
  * Add Build-Depends on dctrl-tools.
  * ltsp-server: Only add nfs-kernel-server to Recommends on Debian.
  * ltsp-server-standalone:
    - Only add nfs-kernel-server to Depends on Debian.
    - Add ltsp-docs to Recommends.
  * Run some "make clean" calls in a dh_autoreconf_clean override, otherwise
    dh_autoreconf_clean may remove files necessary for the generated Makefiles.
  * ltsp-client-builder: Add debhelper token to postinst.

ltsp (5.4.0-1) unstable; urgency=low

  * New upstream version:
    - Rewrite ltsp-update-image:
      + Test that ionice works before using it (needed for some openvz
        containers).

    - ltsp-config:...

[Alkis Georgopoulos (alkisg)]

A quick how-to for those seeking to enable remote logging for ltsp clients in Ubuntu.

1) Uncomment the following lines in /etc/rsyslog.conf:
# provides UDP syslog reception
$ModLoad imudp
$UDPServerRun 514

2) Restart rsyslog:
sudo service rsyslog restart

3) Set the following line in lts.conf:
SYSLOG_HOST=server

4) Restart clients, you can now see their output in the server, with e.g.
tail -f /var/log/syslog

[Alkis Georgopoulos (alkisg)]

Updated how-to for the new rsyslog format and logging to a separate file:

1) Create /etc/rsyslog.d/20-ltsp.conf with the following contents:
ruleset(name="remote") {
    action(type="omfile" file="/var/log/ltsp-clients.log")
}

# bind ruleset to tcp listener and activate it:
module(load="imudp")
input(type="imudp" port="514" ruleset="remote")

2) Restart rsyslog:
sudo service rsyslog restart

3) Set the following line in lts.conf:
SYSLOG_HOST=server

4) Restart clients, you can now see their output in the server, with e.g.
tail -f /var/log/ltsp-clients.log