Hello Thomas, Thanks for reporting this and making Ubuntu better.
about your statement on lsb-release, in 00-header: """" [ -r /etc/lsb-release ] && . /etc/lsb-release if [ -z "$DISTRIB_DESCRIPTION" ] && [ -x /usr/bin/lsb_release ]; then # Fall back to using the very slow lsb_release utility DISTRIB_DESCRIPTION=$(lsb_release -s -d) fi # cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.7 LTS" """" the slowpath is only executed if the DISTRIB_DESCRIPTION variable is not set, at least in my tests. In regards to your statement: """ The content of /etc/update-motd.d/* really, really, really shouldn't be executed if the session in question is not interactive, as it provides no value at all. Unfortunately, to disable it for these non-interactive sessions, we also have to disable it for the interactive ones as well where it has some value (though not enough to make spiking the load on this server through the roof an acceptable tradeoff). """ Considering there IS a way of disabling the dynamic motd contents currently by commenting only the line containing the /run/motd.dynamic wording: # Print the message of the day upon successful login. # This includes a dynamically generated part from /run/motd.dynamic # and a static (admin-editable) part from /etc/motd. # session optional pam_motd.so motd=/run/motd.dynamic session optional pam_motd.so noupdate I'm flagging this bug as a whishlist priority. ** Also affects: update-motd (Ubuntu) Importance: Undecided Status: New ** No longer affects: openssh (Ubuntu) ** No longer affects: base-files (Ubuntu) ** Changed in: update-motd (Ubuntu) Status: New => Triaged ** Changed in: update-motd (Ubuntu) Importance: Undecided => Wishlist -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to base-files in Ubuntu. https://bugs.launchpad.net/bugs/1893716 Title: scripts in /etc/update-motd.d/ run even on login via non-interactive scp and sftp sessions Status in update-motd package in Ubuntu: Triaged Bug description: My client has 200+ devices automatically uploading information via sftp and scp to a server every few minutes. After a recent update, I noticed the load on their server spiking through the roof. Upon investigation, I discovered a horde of landscape-sysinfo and /usr/bin/lsb_release processes running that correlated with login session notifications in /var/log/syslog and the load spikes. It appears that even in non-interactive sessions where this information will never be seen, the configuration options below in /etc/pam.d/sshd cause these items to be launched (in fact, probably everything in /etc/update-motd.d). This only started on the system in question after a recent set of system updates were installed. The content of /etc/update-motd.d/* really, really, really shouldn't be executed if the session in question is not interactive, as it provides no value at all. Unfortunately, to disable it for these non- interactive sessions, we also have to disable it for the interactive ones as well where it has some value (though not enough to make spiking the load on this server through the roof an acceptable tradeoff). # Print the message of the day upon successful login. # This includes a dynamically generated part from /run/motd.dynamic # and a static (admin-editable) part from /etc/motd. #session optional pam_motd.so motd=/run/motd.dynamic #session optional pam_motd.so noupdate Also, looking at the script 00-header in /etc/update-motd.d/, /usr/bin/lsb_release is being improperly launched, as /etc/lsb_release does include the necessary information: [ -r /etc/lsb-release ] && . /etc/lsb-release if [ -z "$DISTRIB_DESCRIPTION" ] && [ -x /usr/bin/lsb_release ]; then # Fall back to using the very slow lsb_release utility DISTRIB_DESCRIPTION=$(lsb_release -s -d) fi # cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=16.04 DISTRIB_CODENAME=xenial DISTRIB_DESCRIPTION="Ubuntu 16.04.7 LTS" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/update-motd/+bug/1893716/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp