PUBLIC MARKS with tags ssh & script

’Scripts Shell sous Linux’ chez ENI 10 novembre 2008 dans Livres Ce livre sur les scripts shell présente la mise en œuvre de projets dans un environnement industriel. Les 5 projets détaillés couvrent la plupart des besoins en scripts rencontrés en entreprise. Ils ont été conçus et présentés de telle sorte que leur adaptation à des besoins spécifiques sera aisée pour le lecteur. Les thèmes couverts traitent de la gestion des comptes utilisateurs, des sauvegardes de fichiers, des sauvegardes systèmes, de la gestion des disques, des communications entre serveurs, des mécanismes de surveillance et des scripts de démarrage. Ces projets abordent des approches différentes de la programmation en shell, tels que les gros projets qui utilisent plusieurs scripts avec des fichiers de configuration et de journalisation, ou le script unique complet et autonome. Des concepts de base sont détaillés comme les menus interactifs, la crontab, des fichiers systèmes, la sécurité SSH et les clés. Les scripts shell traités dans le livre sont en téléchargement sur cette page. A noter que le livre numérique est offert par l’éditeur pour l’achat du livre imprimé jusqu’au 31 décembre 2008. "Scripts Shell sous Linux : Mise en œuvre de 5 projets", de Théo SCHOMAKER et Jean-Marc BARANGER", ENI Editions. 37 euros. ISBN : 978-2-7460-4617-7

Many people use SSH to log in to remote machines, copy files around, and perform general system administration. If you want to increase your productivity with SSH, you can try a tool that lets you run commands on more than one remote machine at the same time. Parallel ssh, Cluster SSH, and ClusterIt let you specify commands in a single terminal window and send them to a collection of remote machines where they can be executed. Why you would need a utility like this when, using openSSH, you can create a file containing your commands and use a bash for loop to run it on a list of remote hosts, one at a time? One advantage of a parallel SSH utility is that commands can be run on several hosts at the same time. For a short-running task this might not matter much, but if a task needs an hour to complete and you need to run it on 20 hosts, parallel execution beats serial by a mile. Also, if you want to interactively edit the same file on multiple machines, it might be quicker to use a parallel SSH utility and edit the file on all nodes with vi rather than concoct a script to do the same edit. Many of these parallel SSH tools include support for copying to many hosts at once (a parallel version of scp) or using rsync on a collection of hosts at once. Because the parallel SSH implementations know about all the hosts in a group, some of them also offer the ability to execute a command "on one host" and will work out which host to pick using load balancing. Finally, some parallel SSH projects let you use barriers so that you can execute a collection of commands and explicitly have each node in the group wait until all the nodes have completed a stage before moving on to the next stage of processing.

Many times, you want to execute a command not only on one server, but also on several servers. For example, find out * Version of kernel * Version of Apache web server * Update static html or images files on all web servers via rsync * Find out user information, server information, memory usage etc * Security/patch checking tentakel I have already covered how to execute commands on multiple Linux or UNIX servers via shell script. The disadvantage of script is commands do not run in parallel on all servers. However, several tools exist to automate this procedure in parallel. With the help of tool called tentakel, you run distributed command execution. It is a program for executing the same command on many hosts in parallel using ssh (it supports other methods too). Main advantage is you can create several sets of servers according requirements. For example webserver group, mail server group, home servers group etc. The command is executed in parallel on all servers in this group (time saving). By default, every result is printed to stdout (screen). The output format can be defined for each group.

Un script de 2001 tout cool qui te permet de controller iTunes via le Terminal. Par conséquent tu peux être pépère sur ton lit, tu changes de track via SSH, normal quoi.