Other (Apt, Tmux, Grep) - MirgDenis/scripts GitHub Wiki

Welcome to the scripts wiki!

Here will be some runbooks, guides and other personal stuff.

Tmux

Turn on XTerm shortcuts

Edit your ~/.tmux.conf and add lines:

set-window-option -g xterm-keys on

In case if you are using PuTTY add one more line

set -g terminal-overrides "xterm*:kLFT5=\eOD:kRIT5=\eOC:kUP5=\eOA:kDN5=\eOB:smkx@:rmkx@"

Grep

Grep by config file without comments and empty lines

cat <config_path> | grep -v '^$\|^#'

-v - select non-matching lines
^$ - remove empty lines
\| - logical and
^# - remove anything which starts with #

Apt

Adding repo gracefully

wget -qO - <key_url> | sudo apt-key add -
echo "deb <repo_url> bionic main" > /etc/apt/sources.list.d/<repo_name>.list
{
        echo 'Package: *'
        echo 'Pin: release o=<release_name>'
        echo 'Pin-Priority: 999'
} > /etc/apt/preferences.d/<repo_name>

In case of Dockerfile you can use ADD to download repo key inside container and avoid installing extra packages for downloading repo key.

Golang

Debuging in Docker

Run golang container with security options

docker run -it --rm --security-opt=seccomp:unconfined golang bash

Get delve

go get github.com/derekparker/delve/cmd/dlv

Get application for debugging, and start debugging with following command

dlv debug <path to main (optional if you are in folder with it)> -- <parameters, flags etc.>

Virtualization

Running aarch64 VM on x86 processor

Install packages

apt update
apt install libvirt-bin qemu-efi qemu-system-aarch64 virtinst

Download cloud image and generate cloud-init iso. Then use following virt-install command to run VM.

virt-install --name=test --machine=virt --arch=aarch64 --memory=2048 --vcpu=2 \
             --boot cdrom,hd --network=default,model=virtio --noautoconsole \
             --disk path=/var/lib/libvirt/images/test,format=raw,device=disk,bus=virtio,cache=none --cdrom=/var/lib/libvirt/images/test-config

To delete this VM you need to delete nvram vars for UEFI.

virsh undefine test
rm /var/lib/libvirt/qemu/nvram/test_VARS.fd
virsh destroy test

Creating cloud-init iso

apt update
apt install genisoimage

Create directory, and put there meta-data and user-data. Substtitute ... with your values. NOTE: you can use meta-data for network configuration.

mkdir cloud-init
cat << EOF >> ./cloud-init/user-data
#cloud-config
password: ...
chpasswd: { expire: False }
ssh_authorized_keys:
  - ssh-rsa ...
EOF
cat << EOF >> ./cloud-init/meta-data
instance-id: ...
hostname: ...
local-hostname: ...
EOF

Generate ISO

mkisofs -o "/var/lib/libvirt/images/test-config" -V cidata -r -J --quiet ./cloud-init/meta-data

LDAP

How to search in ldap with host, port, username, password and pagination

ldapsearch -x -D <username> -w <password> -H <protocol://host:port> -E pr=2147483647/noprompt -b <DN to search>

VIM indentation broken via Putty

In case if indentation in Vim via Putty is broken (typically experienced during pasting text), you need to add following line to ~/.vimrc

if &term =~ "screen"                                                   
    let &t_BE = "\e[?2004h"                                              
    let &t_BD = "\e[?2004l"                                              
    exec "set t_PS=\e[200~"                                              
    exec "set t_PE=\e[201~"                                              
endif