Distributed tools

For last months I needed to maintain a number of heterogeneous servers for mi work, I need to do some usually actions, like update a config file, restart a service, create local users etc.

For this purposes there are a lot of applications, like dsh (or full csm), pysh, shmux and many others (only need to perform a search in google using phrase “distributed shell”). Unfortunately for me, I want a easy-to-parse solution, because I’ve a big (really big) number of servers, and I want a single cut-based/awk parsing, and also I need to do some actions as other users (like root, for example) via sudo. Althought many of the existants solutions offers me a subset of this features, I cannot found a complete solution. So I decided to create one

You can find the code, and some packages in the dtools development site. I was use this solution in production environment from months with excelent results, and you can feel free to use.

Of course, its free (of freedom) software, distributed under MIT license.

Enjoy and remember: feedback are welcome

netstrings implementation

This week I publish a tiny library to manage netstrings, as described in Bernstein’s paper. This library is wirten in C and provide a very basic implementation for small applications. I use this library in some projects for months, and now a publish the code over MIT License in launchpad.

You can visit the page of the project in launchpad, or get the code via bzr:

bzr get lp:netstr

bash ini parser

In some situations i like to use INI files as configuration files, as python do. But bash do not provide a parser for these files, obviously you can use a awk code or a couple of sed calls, but if you are bash-priest and do not want to use nothing more, then you can try the following obscure code:

cfg.parser () {
    IFS=$'\n' && ini=( $(<$1) )              # convert to line-array
    ini=( ${ini[*]//;*/} )                   # remove comments
    ini=( ${ini[*]/#[/\}$'\n'cfg.section.} ) # set section prefix
    ini=( ${ini[*]/%]/ \(} )                 # convert text2function (1)
    ini=( ${ini[*]/=/=\( } )                 # convert item to array
    ini=( ${ini[*]/%/ \)} )                  # close array parenthesis
    ini=( ${ini[*]/%\( \)/\(\) \{} )         # convert text2function (2)
    ini=( ${ini[*]/%\} \)/\}} )              # remove extra parenthesis
    ini[0]=''                                # remove first element
    ini[${#ini[*]} + 1]='}'                  # add the last brace
    eval "$(echo "${ini[*]}")"               # eval the result
}

And then you can parse your ini files as following:

# parse the config file called 'myfile.ini', with the following
# contents::
#   [sec2]
#   var2='something'
cfg.parser 'myfile.ini'

# enable section called 'sec2' (in the file [sec2]) for reading
cfg.section.sec2

# read the content of the variable called 'var2' (in the file
# var2=XXX). If your var2 is an array, then you can use
# ${var[index]}
echo "$var2"

Unfortunately, the cfg.parser() function do no support embedded spaces
in section names… yet

bashdoc: just another documentation tool

bashdoc is a small utility to make documentation automatically from bash scripts, using awk to frontend parser (and you can add your own frontends in awk language), and reStructuredText as backend parser. bashdoc parse the object script (using awk) and create an intermediate documentation in RST, which is parsed in next step using RST backend.

The fronted allows you to parse more complicated scripts (or other than bash scripts) and the backend allows you to make the output in different formats.

You can download the source code from launchpad project page or using bzr version control system:

$ bzr get lp:bashdoc

comida is a bash script designed to create a FTP (or HTTP, or rsync or…) mirror and maintain the archive synchronized with the source. I design this tool when I was working at the Free Software Office (OSL) in the University of A Corunna, and decided to create a new mirror in Spain which host a lot of free software projects. But, we wanted a single tool to manage all mirrors in the archive, with full integration in our web page (yes, we wanted on-the-fly status page).

You can download the source code from launchpad project page or using bzr version control system:

$ bzr get lp:comida

ssh-keysend: a tool to distribute ssh keys

ssh-keysend is a tiny script written in bash which read a number of ssh public keys from a file (according to search pattern) and send these keys to remote hosts (taken from another file, also filtered by specified pattern). The remote host add these keys into authorized_keys file for specified user. Here are an example of use:

$ ssh-keysend bill@gates 10.1.10.*

This example send the key for user bill@gates and send the key to any known_host which match with the pattern 10.1.10.* (yes, it’s a regexp). The key is taken from *.pub files in ~/.ssh/ directory.

You can get the code from launchpad ssh-keysend project page, or get the repository code with bzr:

$ bzr get lp:ssh-keysend