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@kaychaks
Created May 5, 2019 06:55
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#!/usr/bin/env bash
#
# This script is useful to setup additional users in EC2 instances who can login with their own public keys rather than using a global public key
# We should do it via OpsWorks but sometimes when OpsWorks go crazy, we have to take things in our hand
# There will be bugs
#
declare -r script_name="add-user"
log () { echo >&2 "$@"; }
usage () {
cat <<EOF
Usage: $script_name <user name> <path to public key>
NOTE: User name should not have any space and public key file should be present
EOF
}
createUser () {
local username="$1"
getent group admin || groupadd admin
sudo adduser --quiet --home /home/"$username" --shell /bin/bash --ingroup admin "$username" --disabled-password --gecos ""
}
addUserToSudoers () {
local username="$1"
echo "$username ALL=(ALL) NOPASSWD:ALL" | sudo tee -a /etc/sudoers > /dev/null
}
loadSSHKeyForUser () {
local username="$1"
local keyfile="$2"
sudo -u "$username" mkdir /home/"$username"/.ssh
cat "$keyfile" | sudo -u "$username" tee -a /home/"$username"/.ssh/authorized_keys > /dev/null
}
fixPermissionsOnFiles () {
local username="$1"
sudo -u "$username" chmod 600 /home/"$username"/.ssh/*;sudo -u "$username" chmod 700 /home/"$username"/.ssh
}
process_args () {
local username="$1"
local keyfile="$2"
if [[ -n "$username" && -f "$keyfile" ]]; then
createUser "$username"
addUserToSudoers "$username"
loadSSHKeyForUser "$username" "$keyfile"
fixPermissionsOnFiles "$username"
else
usage
fi
}
process_args "$1" "$2"
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