File: /opt/bitnami/scripts/libos.sh
#!/bin/bash
# Copyright Broadcom, Inc. All Rights Reserved.
# SPDX-License-Identifier: APACHE-2.0
#
# Library for operating system actions
# shellcheck disable=SC1091
# Load Generic Libraries
. /opt/bitnami/scripts/liblog.sh
. /opt/bitnami/scripts/libfs.sh
. /opt/bitnami/scripts/libvalidations.sh
# Functions
########################
# Check if an user exists in the system
# Arguments:
# $1 - user
# Returns:
# Boolean
#########################
user_exists() {
local user="${1:?user is missing}"
id "$user" >/dev/null 2>&1
}
########################
# Check if a group exists in the system
# Arguments:
# $1 - group
# Returns:
# Boolean
#########################
group_exists() {
local group="${1:?group is missing}"
getent group "$group" >/dev/null 2>&1
}
########################
# Create a group in the system if it does not exist already
# Arguments:
# $1 - group
# Flags:
# -i|--gid - the ID for the new group
# -s|--system - Whether to create new user as system user (uid <= 999)
# Returns:
# None
#########################
ensure_group_exists() {
local group="${1:?group is missing}"
local gid=""
local is_system_user=false
# Validate arguments
shift 1
while [ "$#" -gt 0 ]; do
case "$1" in
-i | --gid)
shift
gid="${1:?missing gid}"
;;
-s | --system)
is_system_user=true
;;
*)
echo "Invalid command line flag $1" >&2
return 1
;;
esac
shift
done
if ! group_exists "$group"; then
local -a args=("$group")
if [[ -n "$gid" ]]; then
if group_exists "$gid"; then
error "The GID $gid is already in use." >&2
return 1
fi
args+=("--gid" "$gid")
fi
$is_system_user && args+=("--system")
groupadd "${args[@]}" >/dev/null 2>&1
fi
}
########################
# Create an user in the system if it does not exist already
# Arguments:
# $1 - user
# Flags:
# -i|--uid - the ID for the new user
# -g|--group - the group the new user should belong to
# -a|--append-groups - comma-separated list of supplemental groups to append to the new user
# -h|--home - the home directory for the new user
# -s|--system - whether to create new user as system user (uid <= 999)
# Returns:
# None
#########################
ensure_user_exists() {
local user="${1:?user is missing}"
local uid=""
local group=""
local append_groups=""
local home=""
local is_system_user=false
# Validate arguments
shift 1
while [ "$#" -gt 0 ]; do
case "$1" in
-i | --uid)
shift
uid="${1:?missing uid}"
;;
-g | --group)
shift
group="${1:?missing group}"
;;
-a | --append-groups)
shift
append_groups="${1:?missing append_groups}"
;;
-h | --home)
shift
home="${1:?missing home directory}"
;;
-s | --system)
is_system_user=true
;;
*)
echo "Invalid command line flag $1" >&2
return 1
;;
esac
shift
done
if ! user_exists "$user"; then
local -a user_args=("-N" "$user")
if [[ -n "$uid" ]]; then
if user_exists "$uid"; then
error "The UID $uid is already in use."
return 1
fi
user_args+=("--uid" "$uid")
else
$is_system_user && user_args+=("--system")
fi
useradd "${user_args[@]}" >/dev/null 2>&1
fi
if [[ -n "$group" ]]; then
local -a group_args=("$group")
$is_system_user && group_args+=("--system")
ensure_group_exists "${group_args[@]}"
usermod -g "$group" "$user" >/dev/null 2>&1
fi
if [[ -n "$append_groups" ]]; then
local -a groups
read -ra groups <<<"$(tr ',;' ' ' <<<"$append_groups")"
for group in "${groups[@]}"; do
ensure_group_exists "$group"
usermod -aG "$group" "$user" >/dev/null 2>&1
done
fi
if [[ -n "$home" ]]; then
mkdir -p "$home"
usermod -d "$home" "$user" >/dev/null 2>&1
configure_permissions_ownership "$home" -d "775" -f "664" -u "$user" -g "$group"
fi
}
########################
# Check if the script is currently running as root
# Arguments:
# $1 - user
# $2 - group
# Returns:
# Boolean
#########################
am_i_root() {
if [[ "$(id -u)" = "0" ]]; then
true
else
false
fi
}
########################
# Print OS metadata
# Arguments:
# $1 - Flag name
# Flags:
# --id - Distro ID
# --version - Distro version
# --branch - Distro branch
# --codename - Distro codename
# --name - Distro name
# --pretty-name - Distro pretty name
# Returns:
# String
#########################
get_os_metadata() {
local -r flag_name="${1:?missing flag}"
# Helper function
get_os_release_metadata() {
local -r env_name="${1:?missing environment variable name}"
(
. /etc/os-release
echo "${!env_name}"
)
}
case "$flag_name" in
--id)
get_os_release_metadata ID
;;
--version)
get_os_release_metadata VERSION_ID
;;
--branch)
get_os_release_metadata VERSION_ID | sed 's/\..*//'
;;
--codename)
get_os_release_metadata VERSION_CODENAME
;;
--name)
get_os_release_metadata NAME
;;
--pretty-name)
get_os_release_metadata PRETTY_NAME
;;
*)
error "Unknown flag ${flag_name}"
return 1
;;
esac
}
########################
# Get total memory available
# Arguments:
# None
# Returns:
# Memory in bytes
#########################
get_total_memory() {
echo $(($(grep MemTotal /proc/meminfo | awk '{print $2}') / 1024))
}
########################
# Get machine size depending on specified memory
# Globals:
# None
# Arguments:
# None
# Flags:
# --memory - memory size (optional)
# Returns:
# Detected instance size
#########################
get_machine_size() {
local memory=""
# Validate arguments
while [[ "$#" -gt 0 ]]; do
case "$1" in
--memory)
shift
memory="${1:?missing memory}"
;;
*)
echo "Invalid command line flag $1" >&2
return 1
;;
esac
shift
done
if [[ -z "$memory" ]]; then
debug "Memory was not specified, detecting available memory automatically"
memory="$(get_total_memory)"
fi
sanitized_memory=$(convert_to_mb "$memory")
if [[ "$sanitized_memory" -gt 26000 ]]; then
echo 2xlarge
elif [[ "$sanitized_memory" -gt 13000 ]]; then
echo xlarge
elif [[ "$sanitized_memory" -gt 6000 ]]; then
echo large
elif [[ "$sanitized_memory" -gt 3000 ]]; then
echo medium
elif [[ "$sanitized_memory" -gt 1500 ]]; then
echo small
else
echo micro
fi
}
########################
# Get machine size depending on specified memory
# Globals:
# None
# Arguments:
# $1 - memory size (optional)
# Returns:
# Detected instance size
#########################
get_supported_machine_sizes() {
echo micro small medium large xlarge 2xlarge
}
########################
# Convert memory size from string to amount of megabytes (i.e. 2G -> 2048)
# Globals:
# None
# Arguments:
# $1 - memory size
# Returns:
# Result of the conversion
#########################
convert_to_mb() {
local amount="${1:-}"
if [[ $amount =~ ^([0-9]+)(m|M|g|G) ]]; then
size="${BASH_REMATCH[1]}"
unit="${BASH_REMATCH[2]}"
if [[ "$unit" = "g" || "$unit" = "G" ]]; then
amount="$((size * 1024))"
else
amount="$size"
fi
fi
echo "$amount"
}
#########################
# Redirects output to /dev/null if debug mode is disabled
# Globals:
# BITNAMI_DEBUG
# Arguments:
# $@ - Command to execute
# Returns:
# None
#########################
debug_execute() {
if is_boolean_yes "${BITNAMI_DEBUG:-false}"; then
"$@"
else
"$@" >/dev/null 2>&1
fi
}
########################
# Retries a command a given number of times
# Arguments:
# $1 - cmd (as a string)
# $2 - max retries. Default: 12
# $3 - sleep between retries (in seconds). Default: 5
# Returns:
# Boolean
#########################
retry_while() {
local cmd="${1:?cmd is missing}"
local retries="${2:-12}"
local sleep_time="${3:-5}"
local return_value=1
read -r -a command <<<"$cmd"
for ((i = 1; i <= retries; i += 1)); do
"${command[@]}" && return_value=0 && break
sleep "$sleep_time"
done
return $return_value
}
########################
# Generate a random string
# Arguments:
# -t|--type - String type (ascii, alphanumeric, numeric), defaults to ascii
# -c|--count - Number of characters, defaults to 32
# Arguments:
# None
# Returns:
# None
# Returns:
# String
#########################
generate_random_string() {
local type="ascii"
local count="32"
local filter
local result
# Validate arguments
while [[ "$#" -gt 0 ]]; do
case "$1" in
-t | --type)
shift
type="$1"
;;
-c | --count)
shift
count="$1"
;;
*)
echo "Invalid command line flag $1" >&2
return 1
;;
esac
shift
done
# Validate type
case "$type" in
ascii)
filter="[:print:]"
;;
numeric)
filter="0-9"
;;
alphanumeric)
filter="a-zA-Z0-9"
;;
alphanumeric+special|special+alphanumeric)
# Limit variety of special characters, so there is a higher chance of containing more alphanumeric characters
# Special characters are harder to write, and it could impact the overall UX if most passwords are too complex
filter='a-zA-Z0-9:@.,/+!='
;;
*)
echo "Invalid type ${type}" >&2
return 1
;;
esac
# Obtain count + 10 lines from /dev/urandom to ensure that the resulting string has the expected size
# Note there is a very small chance of strings starting with EOL character
# Therefore, the higher amount of lines read, this will happen less frequently
result="$(head -n "$((count + 10))" /dev/urandom | tr -dc "$filter" | head -c "$count")"
echo "$result"
}
########################
# Create md5 hash from a string
# Arguments:
# $1 - string
# Returns:
# md5 hash - string
#########################
generate_md5_hash() {
local -r str="${1:?missing input string}"
echo -n "$str" | md5sum | awk '{print $1}'
}
########################
# Create sha1 hash from a string
# Arguments:
# $1 - string
# $2 - algorithm - 1 (default), 224, 256, 384, 512
# Returns:
# sha1 hash - string
#########################
generate_sha_hash() {
local -r str="${1:?missing input string}"
local -r algorithm="${2:-1}"
echo -n "$str" | "sha${algorithm}sum" | awk '{print $1}'
}
########################
# Converts a string to its hexadecimal representation
# Arguments:
# $1 - string
# Returns:
# hexadecimal representation of the string
#########################
convert_to_hex() {
local -r str=${1:?missing input string}
local -i iterator
local char
for ((iterator = 0; iterator < ${#str}; iterator++)); do
char=${str:iterator:1}
printf '%x' "'${char}"
done
}
########################
# Get boot time
# Globals:
# None
# Arguments:
# None
# Returns:
# Boot time metadata
#########################
get_boot_time() {
stat /proc --format=%Y
}
########################
# Get machine ID
# Globals:
# None
# Arguments:
# None
# Returns:
# Machine ID
#########################
get_machine_id() {
local machine_id
if [[ -f /etc/machine-id ]]; then
machine_id="$(cat /etc/machine-id)"
fi
if [[ -z "$machine_id" ]]; then
# Fallback to the boot-time, which will at least ensure a unique ID in the current session
machine_id="$(get_boot_time)"
fi
echo "$machine_id"
}
########################
# Get the root partition's disk device ID (e.g. /dev/sda1)
# Globals:
# None
# Arguments:
# None
# Returns:
# Root partition disk ID
#########################
get_disk_device_id() {
local device_id=""
if grep -q ^/dev /proc/mounts; then
device_id="$(grep ^/dev /proc/mounts | awk '$2 == "/" { print $1 }' | tail -1)"
fi
# If it could not be autodetected, fallback to /dev/sda1 as a default
if [[ -z "$device_id" || ! -b "$device_id" ]]; then
device_id="/dev/sda1"
fi
echo "$device_id"
}
########################
# Get the root disk device ID (e.g. /dev/sda)
# Globals:
# None
# Arguments:
# None
# Returns:
# Root disk ID
#########################
get_root_disk_device_id() {
get_disk_device_id | sed -E 's/p?[0-9]+$//'
}
########################
# Get the root disk size in bytes
# Globals:
# None
# Arguments:
# None
# Returns:
# Root disk size in bytes
#########################
get_root_disk_size() {
fdisk -l "$(get_root_disk_device_id)" | grep 'Disk.*bytes' | sed -E 's/.*, ([0-9]+) bytes,.*/\1/' || true
}
########################
# Run command as a specific user and group (optional)
# Arguments:
# $1 - USER(:GROUP) to switch to
# $2..$n - command to execute
# Returns:
# Exit code of the specified command
#########################
run_as_user() {
run_chroot "$@"
}
########################
# Execute command as a specific user and group (optional),
# replacing the current process image
# Arguments:
# $1 - USER(:GROUP) to switch to
# $2..$n - command to execute
# Returns:
# Exit code of the specified command
#########################
exec_as_user() {
run_chroot --replace-process "$@"
}
########################
# Run a command using chroot
# Arguments:
# $1 - USER(:GROUP) to switch to
# $2..$n - command to execute
# Flags:
# -r | --replace-process - Replace the current process image (optional)
# Returns:
# Exit code of the specified command
#########################
run_chroot() {
local userspec
local user
local homedir
local replace=false
local -r cwd="$(pwd)"
# Parse and validate flags
while [[ "$#" -gt 0 ]]; do
case "$1" in
-r | --replace-process)
replace=true
;;
--)
shift
break
;;
-*)
stderr_print "unrecognized flag $1"
return 1
;;
*)
break
;;
esac
shift
done
# Parse and validate arguments
if [[ "$#" -lt 2 ]]; then
echo "expected at least 2 arguments"
return 1
else
userspec=$1
shift
# userspec can optionally include the group, so we parse the user
user=$(echo "$userspec" | cut -d':' -f1)
fi
if ! am_i_root; then
error "Could not switch to '${userspec}': Operation not permitted"
return 1
fi
# Get the HOME directory for the user to switch, as chroot does
# not properly update this env and some scripts rely on it
homedir=$(eval echo "~${user}")
if [[ ! -d $homedir ]]; then
homedir="${HOME:-/}"
fi
# Obtaining value for "$@" indirectly in order to properly support shell parameter expansion
if [[ "$replace" = true ]]; then
exec chroot --userspec="$userspec" / bash -c "cd ${cwd}; export HOME=${homedir}; exec \"\$@\"" -- "$@"
else
chroot --userspec="$userspec" / bash -c "cd ${cwd}; export HOME=${homedir}; exec \"\$@\"" -- "$@"
fi
}