Misc Tips, TroubleShooting

Sending commands to LXD containers

Use bash -c "<command>" for commands with wildcards. i.e.

for machine in $(lxc list | grep RUNNING | awk '{print $2}') ;\
    do lxc exec "${machine}" -- bash -c "cat /etc/apt/apt.conf.d/02*" ; done

fish shell is actually a little bit cleaner

for machine in (lxc list | grep RUNNING | awk '{print $2}') ; \
    lxc exec $machine -- bash -c "cat /etc/apt/apt.conf.d/02*" ; end

# change all their time zones
for machine in (lxc list | grep RUNNING | awk '{print $2}') ; \
    lxc exec $machine -- bash -c "timedatectl set-timezone America/Los_Angeles" ; end
# check to see if anyone is logged in before rebooting
for machine in (lxc list | grep RUNNING | awk '{print $2}') ; echo ; \
    echo $machine ; lxc exec $machine -- bash -c "who" ; end

Move LXD container to another Server

# stop the container
lxc stop <container name>
# publish image of container to local *storage*
lxc publish <container name> --alias <image name>
# export the new image to tarball
lxc image export <image name>
# scp tarball to other box
scp a4762b114fecee2e2bc227b9032405642c5286c02009babef7953e011e597bfe.tar.gz server:
# on other box import the image
lxc image import <tarball file name> --alias <image name>
# launch container
lxc launch <image name> <container name>
# assign profile to container
lxc profile assign <container name> <profile name>

Shell into the new running container, update any network interface configurations that you need to, and then restart the container.

See also LXD Container Home Server Networking For Dummies

Ubuntu-Mate-Welcome-Center doesn't work for some repos

Perhaps your apt-cacher-ng proxy server isn't configured to allow traffic through from https sources. Make sure the following is uncommented. This applies for all PPA's that use https.

# /etc/apt-cacher-ng/acng.conf
PassThroughPattern: .*

Quitting Mosh

The key combination to quit mosh it ctrl+6+. Also, WTF?

Updating Caddy Server

You update Caddy Server with a new Go Binary, try to restart caddy.service, and it fails. Maybe you get an error message such as the following listen tcp :80: bind: permission denied and/or listen tcp :443: bind: permission denied.
Fix this error with the following command sudo setcap CAP_NET_BIND_SERVICE=+eip /path/to/caddy

ZFS Disc Error Disc Identification

You created a zpool using /dev/disk-by-id to specify the devices, and now you want to figure out which disks are causing you trouble. For instance, your system log, journalctl | grep -i fail shows read error on /dev/sdc.

You can use lsblk -o MODEL,SERIAL to match the information generated by zpool status.

Byobu/Tmux copy mode

  1. Enter Copy Mode

    • in byobu use key F7
    • in tmux use <prefix> [

  2. Navigate around less/copy buffer using h,j,k,l

  3. Select text

    • <space> begins text selection
    • move cursor around using h,j,k,l
    • <enter> ends text selection

  4. Paste selection in any tmux/byobu window

    • in byobu use alt+insert
    • in tmux use <prefix> ]