Michael Abrahamsen

Nov 24, 2018

Using systemd 

[Unit]
Description=Starts i3lock at suspend time
Before=suspend.target

[Service]
User=username
Type=forking
Environment=DISPLAY=:0
ExecStartPre=
ExecStart=/usr/local/bin/lock_and_blur.sh

[Install]
WantedBy=suspend.target

You may want your computer to lock on sleep (for example if you are using hybrid-sleep ) In that case modify the above script to look like this: See Creating a custom lockscreen with i3lock to setup the lockscreen script

Add a service file to run the script when the computer sleeps or suspends

Create a file /etc/systemd/system/screenlock@.service with the following contents. (Change the username to be your local user account name)

[Unit]
Description=Starts i3lock on sleep
Before=sleep.target

[Service]
User=username
Type=forking
Environment=DISPLAY=:0
ExecStartPre=
ExecStart=/usr/local/bin/lock_and_blur.sh

[Install]
WantedBy=sleep.target

Enable the service by running:
sudo systemctl enable screenlock@username.service again replacing username with the linux account username

posted at 13:24  ·   ·  linux  arch  i3lock  i3  systemd

May 09, 2017

Creating a custom lockscreen with i3lock

Instead of the default i3 lockscreen (which is just a plain white screen), you can show an image as the background. You can create a script to show a blurred image of the content on your screen to get the following effect.

Screenlock

Create the script

The short script below will take a screenshot of your screen, blur it, and add the lock icon:

Create the file at /usr/local/bin/lock_and_blur.sh

#!/usr/bin/env bash

# set the icon and a temporary location for the screenshot to be stored
icon="$HOME/images/lock-icon-light.png"
tmpbg='/tmp/screen.png'

# take a screenshot
scrot "$tmpbg"

# blur the screenshot by resizing and scaling back up
convert "$tmpbg" -filter Gaussian -thumbnail 20% -sample 500% "$tmpbg"

# overlay the icon onto the screenshot
convert "$tmpbg" "$icon" -gravity center -composite "$tmpbg"

# lock the screen with the blurred screenshot
i3lock -i "$tmpbg"

Lock screen after a specific amount of time

You can use the package xautolock to lock the screen after a specific amount of time. To configure, add the following to your i3 config file. This will lock the screen after 5 minutes and give you a warning 30 seconds before the screen locks. You will need notify-osd installed to show the notification.

exec xautolock -detectsleep -time 5 -locker "/usr/local/bin/lock_and_blur.sh" \
  -notify 30 \
  -notifier "notify-send -u critical -t 10000 -- 'locking screen in 30 seconds'"

Further customization

To go a little bit further you can use a package called i3lock-color to customize the color of the feedback ring. The next step is to detect if the background is dark or light and change the lock icon and colors based on that. The final script will look like this:

#!/usr/bin/env bash

lighticon="$HOME/images/lock-icon-light.png"
darkicon="$HOME/images/lock-icon-dark.png"
tmpbg='/tmp/screen.png'

# take a screenshot
scrot "$tmpbg"

# set a threshold value to determine if we should use the light icon or dark
# icon
VALUE="60" #brightness value to compare to

# determine the color of the screenshot
# thanks to [i3lock-fancy](https://github.com/meskarune/i3lock-fancy) for the
# idea of getting the background color to change the icons
COLOR=$(convert "$tmpbg" -gravity center -crop 100x100+0+0 +repage -colorspace hsb \
    -resize 1x1 txt:- | awk -F '[%$]' 'NR==2{gsub(",",""); printf "%.0f\n", $(NF-1)}');

# change the color ring colors to leave the middle of the feedback ring
# transparent and the outside to use either dark or light colors based on the 
# screenshot
if [ "$COLOR" -gt "$VALUE" ]; then #light background, use dark icon
    icon="$darkicon"
    PARAM=(--textcolor=00000000 --insidecolor=00000000 --ringcolor=0000003e \
        --linecolor=00000000 --keyhlcolor=ffffff80 --ringvercolor=ffffff00 \
        --separatorcolor=22222260 --insidevercolor=ffffff1c \
        --ringwrongcolor=ffffff55 --insidewrongcolor=ffffff1c)
else # dark background so use the light icon
    icon="$lighticon"
    PARAM=(--textcolor=ffffff00 --insidecolor=ffffff00 --ringcolor=ffffff3e \
        --linecolor=ffffff00 --keyhlcolor=00000080 --ringvercolor=00000000 \
        --separatorcolor=22222260 --insidevercolor=0000001c \
        --ringwrongcolor=00000055 --insidewrongcolor=0000001c)
fi

# blur the screenshot by resizing and scaling back up
convert "$tmpbg" -filter Gaussian -thumbnail 20% -sample 500% "$tmpbg"

# overlay the icon onto the screenshot
convert "$tmpbg" "$icon" -gravity center -composite "$tmpbg"

# lock the screen with the color parameters
i3lock "${PARAM[@]}" -i "$tmpbg"
posted at 11:04  ·   ·  linux  arch  i3lock  i3

Mar 10, 2017

Setting up ZFS with Arch root install

Configuration overview

The last setup of this machine was an UNRAID install with virtual machines using PCI passthrough. For this setup I am going to run Arch Linux with a root install on ZFS. The root install will allow snapshots of the entire operating system.

Array hardware

  • Boot Drive        - 32 GB USB flash drive
  • Array Storage - 3x 3TB HDD
  • Cache                 - 2x 128GB SSD

Final configuration

The completed setup will have the following zpool configuration and mount points

$ zpool status

  pool: vault
 state: ONLINE
  scan: none requested
config:

    NAME                                             STATE     READ WRITE CKSUM
    vault                                            ONLINE       0     0     0
      mirror-0                                       ONLINE       0     0     0
        ata-ST3000DM001-1CH144_Z1F5W372              ONLINE       0     0     0
        ata-ST3000DM001-1CH144_Z1F5YJ5C              ONLINE       0     0     0
        ata-ST3000DM001-1C6144_Z1F5KYV4              ONLINE       0     0     0
    cache
      ata-Samsung_SSD_850_EVO_120GB_S21TNSAG205110A  ONLINE       0     0     0
      ata-Samsung_SSD_850_EVO_120GB_S21WNX0H404232B  ONLINE       0     0     0

errors: No known data errors

$ zfs mount

vault/ROOT/default              /
vault/home                      /home
vault                           /vault

Create EFI partition on boot drive

Boot into archlive in UEFI mode and create a 512MB EFI partition on the USB drive

# enter into fdisk for the required device
$ fdisk /dev/sdX
$ g # create a new GPT partition table
$ n # create a new partition
$ enter # select partition 1 as default
$ enter # select default start location
$ +512M # end location of 512M after start location

$ t # change the partition type to EFI
$ 0 # in fdisk the EFI system partition is 0
$ w # write changes to disk

Create and configure the pool

You do not need to partition the disks that will be used in the pool as zfs will partition the drives automatically when the pool is created. Use disk id to specify the disks in the pool. You can find disk ids with the command ls /dev/disk/by-id. This install is going to use a 3 way mirror with the SSDs acting as the cache.

Load the kernel module

$ modprobe zfs

Note the -o ashift=12 will use 4096 byte sectors which is what you want for modern disks.

$ zpool create -f -o ashift=12 vault mirror \
ata-ST3000DM001-1CH144_Z1F5W372 \
ata-ST3000DM001-1CH144_Z1F5YJ5C \
ata-ST3000DM001-1C6144_Z1F5KYV4 \
cache \
ata-Samsung_SSD_850_EVO_120GB_S21TNSAG205110A \
ata-Samsung_SSD_850_EVO_120GB_S21WNX0H404232B

Check the status of the pool to make sure it was created correctly.

$ zpool status

  pool: vault
 state: ONLINE
  scan: none requested
config:

    NAME                                             STATE     READ WRITE CKSUM
    vault                                            ONLINE       0     0     0
      mirror-0                                       ONLINE       0     0     0
        ata-ST3000DM001-1CH144_Z1F5W372              ONLINE       0     0     0
        ata-ST3000DM001-1CH144_Z1F5YJ5C              ONLINE       0     0     0
        ata-ST3000DM001-1C6144_Z1F5KYV4              ONLINE       0     0     0
    cache
      ata-Samsung_SSD_850_EVO_120GB_S21TNSAG205110A  ONLINE       0     0     0
      ata-Samsung_SSD_850_EVO_120GB_S21WNX0H404232B  ONLINE       0     0     0

errors: No known data errors

Turn on compression and optimize writes to disk with relatime

#turn on compression
$ zfs set compression=on vault
# optimize writes to disk
$ zfs set relatime=on vault

Create datasets for / and home

$ zfs create -o mountpoint=/ vault/ROOT/default
$ zfs create -o mountpoint=/home vault/home

Specify the dataset that will be used to boot from

$ zpool set bootfs=vault/ROOT/default vault

Unmount zfs volumes and export before installing arch

$ zfs umount -a
$ zpool export vault

Install the base Arch system

Create directories for mountpoints

$ mkdir /mnt/{boot,home}

Mount zfs and boot volumes

$ mount /dev/sdX1 /mnt/boot # boot disk
$ zpool import -d /dev/disk/by-id -R /mnt vault

$ pacstrap -i /mnt base base-devel

Copy the zpool.cache file to the arch install

$ cp /etc/zfs/zpool.cache /mnt/etc/zfs/zpool.cache

Generate the fstab and make sure /boot is mounted

$ genfstab -U -p /mnt >> /mnt/etc/fstab

Add hooks to mkinitcpio.conf and regenerate it

$ vim /mnt/etc/mkinitcpio.conf

# Add zfs after keyboard but before filesystems
HOOKS="base udev autodetect modconf block keyboard zfs filesystems"


# regenerate mkinitcpio
$ mkinitcpio -p linux

Chroot into the Arch install and configure the system

$ arch-chroot /mnt /bin/bash

Add the archzfs repo to /etc/pacman.conf

$ vim /etc/pacman.conf

# add the following in the repository section
[archzfs]
Server = http://archzfs.com/$repo/x86_64

Sign the repository key with the key from AUR

$ pacman-key -r 5E1ABF240EE7A126
$ pacman-key --lsign-key 5E1ABF240EE7A126

Update the system and install zfs

$ pacman -Syyu
$ pacman -S zfs-linux

Enable zfs services

$ systemctl enable zfs.target
$ systemctl enable zfs-import-cache.service

Install the EFI bootloader

bootctl --path=/boot install

Create an entry for Arch in the bootloader

$ vim /boot/loader/entries/arch.conf

# add the following
title     Arch Linux
linux     /vmlinuz-linux
initrd    /initramfs-linux.img
options   zfs=vault/ROOT/default rw

Exit chroot unmount drives and restart

# exit chroot before unmounting
$ umount /mnt/boot
$ zfs umount -a
$ zpool export vault
$ reboot

Apparently when the computer is booting the host id is not available to the system. To fix this, create a hostid file and regenerate mkinitcpio. After rebooting:

$ hostid > /etc/hostid
$ mkinitcpio -p linux
posted at 16:00  ·   ·  linux  arch  zfs

Mar 08, 2017

Creating Arch Linux iso with ZFS installed with EFI system

Adding ZFS to the iso can save you some time when you are experimenting with the setup as you will not have to add the repository and install each time you restart the machine this way.

Download archiso

# switch to root
$ sudo -i or su root

# Install archiso
$ pacman -S archiso

# Create directory to hold our build and copy necessary files
$ mkdir ~/archlive
$ cp -r /usr/share/archiso/configs/releng/* ~/archlive

Add archzfs server to pacman.conf

Edit ~/archlive/pacman.conf and add the following code:

[archzfs]
SigLevel = Optional TrustAll
Server = http://archzfs.com/$repo/x86_64

Add archzfs-linux to packages.x86_64

$ echo 'archzfs-linux' >> ~/archlive/packages.x86_64

Build the image

# create a temporary directory for the build
$ cp -r ~/archlive /tmp 
$ cd /tmp/archlive

# Create /tmp/archlive/out and run the build script
$ mkdir out
$ ./build.sh -v

Create a bootable usb device with the new image

Uselsblk to find the usb in my case /dev/sdc use /dev/sdX to fit your needs. Then run the following command to create the bootable usb:

$ dd bs=4M if=/tmp/archlive/out/archlinux-2017.03.05-dual.iso of=/dev/sdX
status=progress && sync
posted at 22:30  ·   ·  linux  arch  zfs