Unix on Janik von Rotz

Move Docker data directory to new location

Tue, 30 Mar 2021 22:30:50 +0200

The standard data directory used for docker is /var/lib/docker, and since this directory will store all your images, volumes, etc. it can become quite large.

Follow the steps below to move the Docker data directory to a new location. This makes especially sense if you want to avoid running out of disk space on your root partition.

Stop the Docker deamon.

sudo service docker stop

Create a config file /etc/docker/daemon.json

{ 
   "data-root": "/path/to/your/docker" 
}

Copy the current directory to the new directory.

sudo cp -rp /var/lib/docker /path/to/your/docker

Rename the old directory.

sudo mv /var/lib/docker /var/lib/docker.old

Restart the Docker deamon.

sudo service docker start

Test if all services work as expected.

If everything is good, remove the old Docker directory.

sudo rm -rf /var/lib/docker.old

Tmux Cheat Sheet

Wed, 11 Nov 2020 11:01:47 +0100

Tmux is a terminal multiplexer for Unix-like operating systems. It allows multiple terminal sessions to be accessed simultaneously in a single window. It is useful for running more than one command-line program at the same time. It can also be used to detach processes from their controlling terminals, allowing SSH sessions to remain active without being visible.

Install

See https://github.com/tmux/tmux/wiki/Installing for details.

Basics

Start new session.
tmux

Attach to last session.
tmux a

Show time.
ctrl + b t

Kill session.
tmux kill-session

Window

Create new window.
ctrl + b c

Rename new window.
ctrl + b ,

Close window.
ctrl + b &

Select window.
ctrl + b [0-9]

List windows.
ctrl + b w

Enter window index.
ctrl + b '

Swap windows.

ctrl + b :
swap-window -s 3 -t 1

Renumber windows. ctrl + b move-window -r

Pane

Split vertically.
ctrl + b %

Toggle last active pane.
ctrl + b ;

Split horizontally.
ctrl + b "

Switch to pane to the direction.
ctrl + b [h,j,k,l]

Close current pane.
ctrl + b x

Move pane right.
ctrl + b }

Move pane left.
ctrl + b {

Convert pane into a window.
ctrl + b !

Resize pane vertically. ctrl + b + ↑ ctrl + b + ↓

Resize pane horizontally. ctrl + b + ← ctrl + b + →

Session

Detach from session.
ctrl + b d

Attach to last session.
tmux a

Rename session.
ctrl + b $

List sessions.
ctrl + b s

Attach to named session.
tmux a -t name

Start new session.
ctrl + b :new

Copy Mode

Enter copy mode.
ctrl + b [ or v

Search down.
/

Search up.
?

Next keyword occurance.
n

Navigate up and down.
ctrl + u ctrl + d

Start selection.
space

Copy selection.
enter

Paste selection.
ctrl + b ]

List buffers.
ctrl + b :list-buffer

Paste buffer selection.
choose-buffer

Save buffer.
save-buffer buf.txt

Return to normal mode.
ctrl + c

Plugins

tmux-resurrect

Save session.
ctrl + b ctrl + s

Restore session.
ctrl + b ctrl + r

Another Vim Cheat Sheet

Thu, 06 Jun 2019 11:31:39 +0200

Getting started with Vim is not easy. Fueled by an entirely different ecosystem of plugins, scripts and obscure workflows it is difficult to see the advantage of using Vim. But, to watch experienced people using Vim is always impressive and makes one eager to learn it.

This cheat sheet does not intend to provide you with a list of plugins and dotfiles, but aims at giving an overview of the most common commands. I assmelbed this document while learning to vim.

In order to unsertand these command I recommend to read about the following Vim topics first:

leader key
plugins with plug
modes and buffers

Sections

Plugins

Plugins are managed by vim plug. My vim config including the list of plugins is available at GitHub - janikvonrotz/dotfiles.

fzf vim

Open file with fzf in new split or tab.

ctrl + t # tab split
ctrl + x # split
ctrl + v # vsplit

Search git files with key bindings.
leader + f

fugitive

Resolve merge conflicts.

# open conflicted file

# run diff command
:Gdiff

# navigate between remote and local version

# use diff put to select changes
dp

# write changes
:Gwrite

Checkout file from index.
:Gread

Show file history.
:Gblame

Rebase interactive.

# Rebase last 10 commits
git rebase -i HEAD~10

# Navigate and replace word
cw

# Enter letter for commands
d

vim indent guides

Show indents.
leader + ig

Basics

Save current file.
:w

Override current file.
:w!

Save and quit.
:wq or ZZ

Reload current file.
:e

Quit vim.
:q

Quite all splits and tabs.
:qa

Profile

Reload vim profile.
:so $MYVIMRC or :source %

Modes

Enter visual character selection mode.
v

Enter visual line selection mode.
V

Enter insert mode. i

Enter insert mode after current character.
a

Exit mode.
ctrl + c or ESC

Open new or existing file inside vim.
:e /path/to/file

Open file browser inside vim.
:e /path/to/direcotry

Navigate with keys.

h # left
j # down
k # up
ö # right
w # word
e # end
b # back
$ # end of line
0 # beginning of line

Navigate pages.

ctrl + u # page up
ctrl + d # page down
G # go to bottom
gg # go to top

List previous opened files.
:jumps

Open the last file.
:e#

Navigate search results.

n # next
shift + n # previous

Session

Save the current session.
:mksession

Open vim with session file.
vim -S Session.vim

Edit

Undo changes.
u

Redo changes.
ctrl + r

Copy and paste.

# cut current selection
d
# delete word
dw
# copy current selection
y
# cut the current line
dd
# copy current line
yy
# paste
p

Search and replace in file.
:%s/old/new/g

Add line below current line.
o

Tell vim to not autoindent or otherwise alter the format of your pasted text.
:set paste or :set nopaste

Move line up or down.
ddp and dd{j,k}p or :m{+,-}{i} and :m{i}

Select

Select text between character.
vi{c}

Select current word.
vw

Window

Split window vertically.
:vs

Split window horizontally.
:sp

Switch between splits.
ctrl + w & {h,j,k,l}

Leader

Set leader key.
:let mapleader = "-"

Tabs

Open file in new tab.
:tabnew /path/to/file

Open multiple files in tabs.

:args path/to/files/*
:tab all

Navigate tabs.

gt # go to next tab
gT # go to previous tab
{i}gt # go to tab in position i

Shell

Run shell command in split pane.
:new | 0read ! command

Buffer

Reload all buffers.
:bufdo e

Sources

Learn Vimscript the Hard Way

Jesse Leite - It’s dangerous to Vim alone! Take Fzf

Thoughtbot - Vim Splits - Move Faster and More Naturally

Update Windows Subsystem for Linux

Tue, 30 Jan 2018 10:32:51 +0000

Today I learned that certain Ubuntu package versions are bound to the release version of Ubuntu. For example the only available version of the password store tool pass for Ubuntu LTS 14.04 (trusty) is 1.4.2-3. If you need a newer version you have to update Ubuntu first. Usually this no big deal, however, if you work with Windows Subsystem for Linux (WSL) it is a big deal. The WSL release is bound to the Windows version. In result to update a package you have to update your Windows first.

Common Solution

In case your Windows version is newer than your WSL version uninstall WSL.

lxrun /uninstall /full

And reinstall WSL.

lxrun /install

Once finished you can check the version with lsb_release -a.

Ugly Hack

If you work in corporate environment you might not be able to get the latest Windows release. In this case you have to update Ubuntu itself which is not supported by Microsoft.

First we have to prevent certain packages from being updated.

sudo -S apt-mark hold procps strace sudo

These commands have been modified especially for WSL.

Next run the release upgrade command.

sudo -S env RELEASE_UPGRADER_NO_SCREEN=1 do-release-upgrade

If the update successfully finished you should be on the latest release.

bin/bash^M: bad interpreter

Wed, 14 Aug 2013 08:00:19 +0000

If you’re using windows and linux/unix and your also a system administrator who likes to script. The chances are high that you’ll get this error when executing a script on a linux/unix machine that has been made on a windows machine: bin/bash^M: bad interpreter: No such file or directoy

The ^M character is a windows line break, which linux/unix can’t interpret. The solution is easy, use dos2unix [filename] and everything should work fine.

Unix on Janik von Rotz

Move Docker data directory to new location

Tmux Cheat Sheet

Install

Basics

Window

Pane

Session

Copy Mode

Plugins

tmux-resurrect

Another Vim Cheat Sheet

Sections

Plugins

fzf vim

fugitive

vim indent guides

Basics

Profile

Modes

Navigation

Session

Edit

Select

Window

Leader

Tabs

Shell

Buffer

Sources

Update Windows Subsystem for Linux

Common Solution

Ugly Hack

bin/bash^M: bad interpreter