kompetenzbolzen / ltask

ltask

lightweight remote task management

Usage

ltask [OPTIONS] TASK TARGET
Options:
	-H HOST		Add HOST to target hosts. can be used
			to target single hosts without defining
			a custom target
	-p		Force parallel execution
	-h		print this help text

Output

All output from targets is printed to STDOUT, prefixed by the hostname. This also includes text sent to STDERR, which is prefixed by [ERR]. Text is displayed "as it comes", not grouped by host. Status and error messages are printed to STDERR. In Linear execution mode, ltask displays a progress meter.

How it works

ltask executes scripts (tasks) on remote hosts and hostgroups (targets) via SSH, either linearly if user input is required, or in parallel. Tasks and targets are written in bash, thus are very flexible. No special Software is required, neither on the host nor on the target.

Tasks

A task contains two parts: the setup and the execution. Setup is executed by ltask on the master machine to set configuration variables like username and which SSH identity to use, Execution is run on targets.

The task has to decide which part to run based on the envvar HOSTMODE=yes, which is only set in the host environment. If HOSTMODE is empty/not set it defaults to execution mode. The setup must set the TASK_ISSET variable to any non-empty value on success.

Reference for environment variables

# To be set by task
SSH_USER		username to connect as
SSH_IDENTITY	path to ssh-key used for authentification of specified user
FILES		Array of Files to copy over before script invocation
INCLUDES		Array of libraries to include
PARALLEL		Enable parallel execution (yes/[no])
#
# Available in setup
ASSET_DIR		path to folder where eg keys are stored
TOOL_DIR		path to helper script folder

Tasks are stored in tasks/

Example

Targets

Targets define hostgroups for tasks to target. They aren't executed but sourced by ltask, thus must be written in bash. Hosts are stored in the HOSTS array with format hostname[:port]. The port should only be specified if != 22 to avoid double mentions. HOSTS is checked for duplicate, host:22 and host would produce the same result but are not caught by duplicate search.

Targets are stored in targets/

Example

Libraries

Libraries are scripts which are executed on the remote host before the main task. Their purpose is to define generic interfaces for different types of hosts.

Libraries are stored in libs/

Example

License

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.