open-im-server/docs/contrib/util-scripts.md

OpenIM Bash Utility Script

This script offers a variety of utilities and helpers to enhance and simplify operations related to the OpenIM project.

Table of Contents

• OpenIM Bash Utility Script
  • Table of Contents
  • brief descriptions of each function
  • Introduction
  • Usage
    • SSH Key Setup
  • openim::util::ensure-gnu-sed
  • openim::util::ensure-gnu-date
  • openim::util::check-file-in-alphabetical-order
  • openim::util::require-jq
  • openim::util::md5
  • openim::util::read-array
  • Color Definitions
  • openim::util::desc and related functions
  • openim::util::onCtrlC
  • openim::util::list-to-string
  • openim::util::remove-space
  • openim::util::gencpu
  • openim::util::gen-os-arch
  • openim::util::download-file
  • openim::util::get-public-ip
  • openim::util::extract-tarball
  • openim::util::check-port-open
  • openim::util::file-lines-count

brief descriptions of each function

Englist:

1. openim::util::ensure-gnu-sed - Determines if GNU version of sed exists on the system and sets its name.
2. openim::util::ensure-gnu-date - Determines if GNU version of date exists on the system and sets its name.
3. openim::util::check-file-in-alphabetical-order - Checks if a file is sorted in alphabetical order.
4. openim::util::require-jq - Checks if jq is installed.
5. openim::util::md5 - Outputs the MD5 hash of a file.
6. openim::util::read-array - Reads content from standard input into an array.
7. openim::util::desc - Displays descriptive information.
8. openim::util::run::prompt - Displays a prompt.
9. openim::util::run::maybe-first-prompt - Possibly displays the first prompt based on whether it's started or not.
10. openim::util::run - Executes a command and captures its output.
11. openim::util::run::relative - Returns paths relative to the current script.
12. openim::util::onCtrlC - Performs an action when Ctrl+C is pressed.
13. openim::util::list-to-string - Converts a list into a string.
14. openim::util::remove-space - Removes spaces from a string.
15. openim::util::gencpu - Retrieves CPU information.
16. openim::util::gen-os-arch - Generates a repository directory based on the operating system and architecture.
17. openim::util::download-file - Downloads a file from a URL.
18. openim::util::get-public-ip - Retrieves the public IP address of the machine.
19. openim::util::extract-tarball - Extracts a tarball to a specified directory.
20. openim::util::check-port-open - Checks if a given port is open on the machine.
21. openim::util::file-lines-count - Counts the number of lines in a file.

Introduction

This script is mainly used to validate whether the code is correctly formatted by gofmt. Apart from that, it offers utilities like setting up SSH keys, various wait conditions, host and platform detection, documentation generation, etc.

Usage

SSH Key Setup

To set up an SSH key:

#1. Write IPs in a file, one IP per line. Let's name it hosts-file.
#2. Modify the default username and password in the script.
hosts-file-path="path/to/your/hosts/file"
openim:util::setup_ssh_key_copy "$hosts-file-path" "root" "123"

openim::util::ensure-gnu-sed

Ensures the presence of the GNU version of the sed command. Different operating systems may have variations of the sed command, and this utility function is used to make sure the script uses the GNU version. If it finds the GNU sed, it sets the SED variable accordingly. If not found, it checks for gsed, which is usually the name of GNU sed on macOS. If neither is found, an error message is displayed.

openim::util::ensure-gnu-date

Similar to the function for sed, this function ensures the script uses the GNU version of the date command. If it identifies the GNU date, it sets the DATE variable. On macOS, it looks for gdate as an alternative. In the absence of both, an error message is recommended.

openim::util::check-file-in-alphabetical-order

This function checks if the contents of a given file are sorted in alphabetical order. If not, it provides a command suggestion for the user to sort the file correctly.

openim::util::require-jq

Verifies the installation of jq, a popular command-line JSON parser. If it's not present, a prompt to install it is displayed.

openim::util::md5

A cross-platform function that computes the MD5 hash of its input. This function takes into account the differences in the md5 command between macOS and Linux.

openim::util::read-array

A function designed to read from stdin and populate an array, line by line. It's provided as an alternative to mapfile -t and is compatible with bash 3.

Color Definitions

The script also defines a set of colors to enhance its console output. These include colors like red, yellow, green, blue, cyan, etc., which can be used for better user experience and clear logs.

openim::util::desc and related functions

These functions seem to aid in building interactive demonstrations or tutorials in the terminal. They use the pv utility to control the display rate of the output, emulating typing. There's also functionality to handle user prompts and execute commands while capturing their output.

openim::util::onCtrlC

Handles the CTRL+C command. It terminates background processes of the script when the user interrupts it using CTRL+C.

openim::util::list-to-string

Transforms a list format (like [10023, 2323, 3434]) to a space-separated string (10023 2323 3434). Also removes unnecessary spaces and characters.

openim::util::remove-space

Removes spaces from a given string.

openim::util::gencpu

Fetches the number of CPUs using the lscpu command.

openim::util::gen-os-arch

Identifies the operating system and architecture of the system running the script. This is useful to determine directories or binaries specific to that OS and architecture.

openim::util::download-file

This function can be used to download a file from a URL. If curl is available, it uses curl. If not, it falls back to wget.

function openim::util::download-file() {
  local url="$1"
  local dest="$2"

  if command -v curl &>/dev/null; then
    curl -L "${url}" -o "${dest}"
  elif command -v wget &>/dev/null; then
    wget "${url}" -O "${dest}"
  else
    openim::log::error "Neither curl nor wget available. Cannot download file."
    return 1
  fi
}

openim::util::get-public-ip

Fetches the public IP address of the machine.

function openim::util::get-public-ip() {
  if command -v curl &>/dev/null; then
    curl -s https://ipinfo.io/ip
  elif command -v wget &>/dev/null; then
    wget -qO- https://ipinfo.io/ip
  else
    openim::log::error "Neither curl nor wget available. Cannot fetch public IP."
    return 1
  fi
}

openim::util::extract-tarball

This function extracts a tarball to a specified directory.

function openim::util::extract-tarball() {
  local tarball="$1"
  local dest="$2"

  mkdir -p "${dest}"
  tar -xzf "${tarball}" -C "${dest}"
}

openim::util::check-port-open

Checks if a given port is open on the local machine.

function openim::util::check-port-open() {
  local port="$1"
  if command -v nc &>/dev/null; then
    echo -n > /dev/tcp/127.0.0.1/"${port}" 2>&1
    return $?
  elif command -v telnet &>/dev/null; then
    telnet 127.0.0.1 "${port}" 2>&1 | grep -q "Connected"
    return $?
  else
    openim::log::error "Neither nc nor telnet available. Cannot check port."
    return 1
  fi
}

openim::util::file-lines-count

Counts the number of lines in a file.

function openim::util::file-lines-count() {
  local file="$1"
  if [[ -f "${file}" ]]; then
    wc -l < "${file}"
  else
    openim::log::error "File does not exist: ${file}"
    return 1
  fi
}