IT notes

DoH Firefox

Open firefox and type: about:config Search for: network.trr.uri Probably you already have: https://mozilla.cloudflare-dns.com/dns-query If not add it or use something like: https://cloudflare-dns.com/dns-query https://dns.quad9.net/dns-query Then enable network.trr.mode by setting it to 2 Set network.trr.mode to 2 make DNS Over HTTPS the browser’s first choice but use regular DNS as a fallback (0 is “off by default”, 1 lets Firefox pick whichever is faster, 3 for TRR only mode, 5 to explicitly turn it off).

osascript

In macOS, to find a path of an application, for example Chromium: $ osascript -e 'POSIX path of (path to application "Chromium")'

Galera

To periodically check status of the cluster, create a script (/tmp/xx): #!/bin/sh mysql --defaults-file=/path/to/.my.cnf -s -e \ "SHOW GLOBAL STATUS WHERE Variable_name IN ('wsrep_ready', 'wsrep_cluster_size', 'wsrep_cluster_status', 'wsrep_connected', 'wsrep_local_state', 'wsrep_local_index');" And run it with: watch sh /tmp/xx If single node alive (ERROR 1047 WSREP has not yet prepared node for application use): SET GLOBAL wsrep_provider_options='pc.bootstrap=YES'; This node can be used now has the new master so others nodes can recover from it.

galera alter

To prevent bloking the cluster while doing ALTERS (SCHEMA UPGRADES), do this per node: SET wsrep_OSU_method='RSU'; Then Run the ALTER statement once done reset the Schema Upgrade method back to Total Order Isolation. SET wsrep_OSU_method='TOI'; http://galeracluster.com/documentation-webpages/clusterstallonalter.html http://galeracluster.com/documentation-webpages/schemaupgrades.html

mojave Iso

Create 12 GB tmp disk: hdiutil create -o /tmp/Mojave.cdr -size 12000m -layout SPUD -fs HFS+J Attach the disk: hdiutil attach /tmp/Mojave.cdr.dmg -noverify -mountpoint /Volumes/install_build Extract the installer: sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/install_build Create the iso mv /tmp/Mojave.cdr.dmg ~/Desktop/InstallSystem.dmg hdiutil detach /Volumes/Install\ macOS\ Mojave hdiutil convert ~/Desktop/InstallSystem.dmg -format UDTO -o ~/Desktop/Mojave.iso Rename Mojave.iso.cdr to Mojave.iso

jamf

softwareupdate -l to see if there are macOS updates available. softwareupdate -ia to install all updates. sudo jamf policy to run all outstanding policies and updates for the apps, sudo jamf recon to update the inventory on the server.

stty

If reset can’t clean your terminal, give a try to: stty sane

tmux

Set window title: <c-b>, Get pannel number: <c-b>q Show clock: <c-b>t Move pane to a new window: <c-b>! Join panes: <c-b>: join-pane -s 0 -t 3 move pane 1 to window 3 <c-b>: join-pane -t :1 move current pane to window 1 Create a new session: <c-b>: new -s <name> List sessions: <c-b>s <c-b>w expanded Move pane to a another session: <c-b>m mark the pane <c-b>w go to the destination window/session <c-b>: join-pane or go to the pane you want to move, check the session name and windows you would like to move and try:

Block SSH on MacOS

To block incoming ssh connections, edit the /etc/pf.conf and add the following line at the bottom: block in log quick proto tcp from any to any port 22 You can use vim or use something like this: sudo sh -c "echo 'block in log quick proto tcp from any to any port 22' >> /etc/pf.conf" Then reload the pfrules: sudo pfctl -Fa -f /etc/pf.conf For this to work the firewall must be enabled.

Processlist

Run show processlist every second: mysqladmin -uroot -p -i 1 processlist -i 1 stands for interval one second