Ananta (formerly Hydra)

Ananta is a powerful command-line tool designed to simplify simultaneous SSH command execution across multiple remote hosts. It enhances workflows, automates repetitive tasks, and improves efficiency for system administrators and developers managing distributed systems.

Namesake

Ananta draws inspiration from Ananta Shesha or Ananta Nagaraja (อนันตนาคราช), the many-headed serpentine demigod from Hindu mythology deeply rooted in Thai culture.

Initially, this project was named Hydra, referencing the many-headed serpent in Greek mythology. However, due to the abundance of projects named Hydra or hydra-* on PyPI (e.g., the previous project at https://pypi.org/project/hydra-ssh/), it was renamed to Ananta. The commands you now use are ananta, which is shorter, more distinctive, and easier to remember than hydra-ssh.

Features

• Concurrent execution of commands across multiple remote hosts
• Flexible host list configuration in TOML or CSV format
• SSH authentication with public key support
• Lightweight and user-friendly command-line interface
• Interactive Text User Interface (TUI) for real-time command execution and output viewing
• Color-coded output for easy host differentiation
• Option to separate host outputs for clarity
• [non-TUI mode] Support for cursor control codes for specific layouts (e.g., fastfetch, neofetch)

Installation

System Requirements

• Python 3.10 or higher
• pip package manager
• Required dependencies: asyncssh, argparse, asyncio, urwid (for TUI mode)
• Optional: uvloop (Unix-based systems) or winloop (Windows) for enhanced performance
• For TOML host files on Python 3.10: tomli (automatically installed)

Installing via pip

Install Ananta using pip:

pip install ananta --user

Install Ananta with uvloop or winloop for speed enhancement:

pip install ananta[speed] --user

Note: Ensure Python 3.10 or higher is installed. For TOML host files, Python 3.10 requires tomli, while Python 3.11 and above use the built-in tomllib. If you previously used hydra-ssh, update to pip install ananta to get the latest version. The urwid library is automatically installed for TUI mode support.

Usage

Hosts File Format

Ananta supports host files in TOML or CSV format, allowing flexible configuration of remote hosts. Below are the structures for each format. Note: The TOML format is recommended for its clarity and ease of use. Any hosts file without .toml extension will be treated as a CSV file.

TOML Host File

Create a TOML file with a [default] section (optional) and host sections. Example:

[default]
port = 22
username = "user"
key_path = "#"
tags = ["common"]

[host-1]
ip = "10.0.0.1"
port = 2222
key_path = "/home/user/.ssh/id_ed25519"

[host-2]
ip = "10.0.0.2"
tags = ["web"]

[host-3]
ip = "10.0.0.3"
tags = ["arch", "web"]

["host-4"]
ip = "10.0.0.4"
tags = ["ubuntu", "db"]

• [default] Section:
  • Optional section to set default values for port, username, key_path, and tags.
  • key_path can be # to use the default SSH key which can be specified via -k or common keys in ~/.ssh/.
  • Fields not specified in a host section will use these defaults (except ip, which is required).
  • tags: Default tags applied to all hosts, appended to host-specific tags.
• Host Sections:
  • Each section (e.g., [host-1]) defines a host with the following fields to override defaults:
    • ip: Required IP address or resolvable hostname
    • port: SSH port
    • username: SSH username
    • key_path: Path to SSH private key
    • tags: Optional list of tags (e.g., ["web", "prod"])
• Tags:
  • Tags from [default] are appended to tags specified in each host section.
  • For example, if default.tags = ["common"] and host-3.tags = ["arch", "web"], host-3 will have tags ["common", "arch", "web"].
  • Use the -t option to filter hosts by tags (e.g., -t common,web matches hosts with any of these tags).
• Note: TOML parsing requires tomli on Python 3.10 (included in Ananta's dependencies) or tomllib on Python 3.11 and above.

CSV Host File

Create a CSV file with the following structure:

#alias,ip,port,username,key_path,tags(optional - colon separated)
host-1,10.0.0.1,2222,user,/home/user/.ssh/id_ed25519
host-2,10.0.0.2,22,user,#,web
host-3,10.0.0.3,22,user,#,arch:web
host-4,10.0.0.4,22,user,#,ubuntu:db

• Lines starting with # are ignored.
• Fields:
  • alias: Unique name for the host
  • ip: IP address or resolvable hostname
  • port: SSH port number
  • username: SSH username
  • key_path: Path to SSH private key, or # to use the default key (via -k or common keys in ~/.ssh/)
  • tags: Optional tags, separated by colons (e.g., web:db)
• Tags: Used for filtering hosts with the -t option (e.g., -t web,db).

Running Commands

Run commands on remote hosts with:

ananta <options> [hosts file] [command]

Examples:

# Run 'uptime' on all hosts in a CSV hosts file
$ ananta hosts.csv uptime

# Run 'sensors' with separate output on all hosts in a CSV hosts file
$ ananta -s host.csv sensors

# Run 'fastfetch' with cursor control enabled and separate output on all hosts in a TOML hosts file
$ ananta -cs hosts.toml fastfetch

# Filter hosts by tags 'web' or 'db' (CSV hosts file)
$ ananta -t web,db hosts.csv uptime

# Filter hosts by tags 'common' or 'web' (TOML hosts file, includes default tags)
$ ananta -t common,web hosts.toml uptime

# Update Arch Linux hosts (TOML hosts file)
$ ananta -t arch hosts.toml sudo pacman -Syu --noconfirm

Text User Interface (TUI) Mode

Ananta provides an interactive Text User Interface (TUI) powered by the urwid library, allowing real-time command input and output viewing across multiple remote hosts. The TUI mode is ideal for interactive sessions where you want to monitor command outputs as they stream in.

Launching TUI Mode:

Launch the TUI with the --tui flag:

ananta --tui [hosts file] [initial command]

Examples:

# Launch TUI with a TOML hosts file and no initial command
$ ananta --tui hosts.toml

# Launch TUI with a CSV hosts file and run 'uptime' initially
$ ananta --tui hosts.csv uptime

# Launch TUI with tag filtering and an initial command
$ ananta --tui -t web,db hosts.toml "df -h"

Using the TUI:

• Input Prompt: At the >>> prompt, type commands to execute on all connected hosts.
• Output Display: Outputs from each host are displayed with color-coded host names for clarity.
• Navigation: Use the arrow keys or mouse to scroll through the output.
• Exit: Type exit or press Ctrl+C or Ctrl+D to quit the TUI.
• Options: Supports -t (host tags), -k (default key), -s (separate output), and -e (allow empty lines) as in non-TUI mode. Note that -n (no-color), -w (terminal width), and -c (cursor control) are ignored in TUI mode, as the TUI handles these internally.

Notes:

• Requires the urwid library, automatically installed with pip install ananta.
• The TUI mode streams output in real-time for interleaved display or waits for complete output with -s (separate output).
• Cursor control codes are stripped to ensure proper rendering in the TUI.

Options

Single-letter options are case-insensitive.

• -n, --no-color: Disable colorized output
• -s, --separate-output: Display output from each host separately
• -t, --host-tags: Filter hosts by tag(s), comma-separated (e.g., web,db)
• -w, --terminal-width: Manually set terminal width
• -e, --allow-empty-line: Permit printing of empty lines
• -c, --allow-cursor-control: Enable cursor control codes (e.g., for fastfetch or neofetch)
• -v, --version: Display the Ananta version
• -k, --default-key: Specify the default SSH private key
• --tui: Launch the Text User Interface (TUI) mode

Demo

Contributing

We welcome contributions to Ananta! Whether you're fixing bugs, adding features, or improving docs, check out our CONTRIBUTING.md for details on how to get started.

License