Create daemon user in linux

create-daemon-user.sh

#!/usr/bin/env bash

# ------
# Creates a daemon user in linux
# usage: create-daemon-usr.sh <username>
# ------

# Add user
/usr/sbin/useradd -r $1

# Remove shell
/usr/sbin/usermod --shell /sbin/nologin "$1"

# Create Daemon home directory
mkdir -p "/var/lib/$1"

# Move user home directory to /var/lib/{username}
/usr/sbin/usermod -d "/var/lib/$1" "$1"

# Make daemon user owner for their files in their home directory
chown -R "$1:$1" "/var/lib/$1"

prepare-daemon-env.sh

#!/usr/bin/env bash

# ------
# Prepares home directory of daemon user in linux
# making symlinks of rc files from /opt directory
# $1 = HOME DIR
# $2 = USERNAME
# usage: prepare-daemon-env.sh <home_dir> <username>
# ------

DAEMON_USER="$2"
DAEMON_HOME="$1/"
SAMBA_PWD_EXT=".smbpasswd"
OPT_DIR=/opt

# Make symlink to mutt and msmtp
ln -s /opt/.muttrc "$DAEMON_HOME/"
ln -s /opt/.msmtprc "$DAEMON_HOME/"

# msmtpq directories
mkdir -p "$DAEMON_HOME/.msmtp.queue"
mkdir -p "$DAEMON_HOME/.msmtp"

# aria2 directories and files
atouch ".cache/aria2/dht.dat"
atouch ".cache/aria2/dht6.dat"
touch "aria2.session"

# Make symlink to samba password for autofs
for FILE in "$OPT_DIR/*$SAMBA_PWD_EXT"; do ln -s "$FILE" "$DAEMON_HOME"; done

# Make daemon user owner for their files in their home directory
chown -R "$DAEMON_USER:$DAEMON_USER" "$DAEMON_HOME/"

run-as.sh

#!/usr/bin/env bash

# ---
# Test daemon user privileges
# usage: run-as.sh <username> "<command>"
# ---

$BASH_USER="$1"
$COMMAND="$2"

# sudo -u transmission bash -c 'echo "$HOME"'
sudo -u "$BASH_USER" bash -c "'$COMMAND'"