Updian

RobHost GmbH [[email protected]], 2007-2013

License: GPLv2+

PLEASE NOTE THAT THIS SOFTWARE COMES WITH ABSOLUTELY NO WARRANTY!

What is it good for?

Updian is a minimalistic update-engine for DEBIAN GNU/Linux based machines (and other flavours like Ubuntu based on APT) and, since v0.4, for machines with YUM such as CentOS. You can use it to maintain all your machines remotely over a simple web interface written in Python. There are 2 cronjobs, one checks for updates, another does them. You can choose from the webinterface which servers to update (it shows up the packages) and read logs after the updates are done.

Updian does not need any databases, all data is stored in (mostly empty) flatfiles. It can manage a high number of servers, we've tested/used it with 100+ servers without any problems...

Actually, Updian only does apt-get upgrade, not dist-upgrade. So it's a good idea to run apticron or anything in parallel on the remote machines to keep informed about upcoming dist-upgrades. Apticron is also good for checking the correctness of Updian - it mails you the updates every day including changelog. These you can now install with Updian. If Updian is working correctly, apticron should mail you the same update-infos (except dist-upgrades) as Updian shows up in the webfrontend.

For every server Updian creates an logfile, so you're always informed about updates made. The logfiles are available through the webfrontend.

Requirements

• Any Linux distribution on the machine which runs Updian (local-side)

• Debian GNU/Linux or other apt-running systems (Ubuntu, Knoppix ...) or yum-running systems (CentOS, RHEL, Fedora Core ...) on the remote-side

• Python 2.6 or newer (local-side)

• Fabric and pip for automated installation (local-side)

• a crond if you want to automate updian's checking and updating (local-side)

• Access as root to all involved machines (gaining root via sudo is also supported)

• Exchanged SSH-publickeys between the local machine running Updian and the remote servers

  • that means you can login from the machine running Updian to the remote server via ssh <remote-server> without entering a password

  • Howto: On the machine running Updian:

    ssh-keygen -t rsa
    cat ~/.ssh/id_rsa.pub | ssh remote-user@remote-server cat - ">>" ~/.ssh/authorized_keys
    # or 'ssh-copy-id remote-server'
    

• Optional: Web server with WSGI support or a separate WSGI application server (local-side, see below)

Installation

Using Updian's fabfile (recommended)

• Change directory to where Updian shall be installed (Updian's home directory)
• Download the latest fabfile
• Run fab and follow the onscreen instructions.
• Add cronjobs for fully automated updates (see Example crontab entries).

From snapshot archive (manually)

• Extract the files to a folder on your server (the machine where Updian should run).
• Run updiancmd init_cfg to create an example configuration file.
• Edit the file config.ini according to the instructions inside the file.
• Install Updian's dependencies listed in requirements.txt (e.g. via pip: pip install -r requirements.txt). Note: It is recommended to use a virtual environment for production usage (see virtualenv documentation).
• Optional: Use updiancmd setpw to create one or more users for basic authentication. If you skip this everyone on the network you serve Updian on will be able to access it without restriction as long as you don't add any protection upstream.
• Run updiancmd runserver <local ip address> (omitting the ip address argument leads to serving Updian on the loopback interface).
• Open http://yourhost:5000/ in your web browser.
• Click on "Servers" and add your servers.
• For testing purposes run updiancmd collect on your shell.
  • You should see some output and (if there are updates) the updates should be visible via the web interface.
• Run updiancmd update if you want Updian to update your chosen servers.
• Add cronjobs for fully automated updates (see Example crontab entries).
• If you plan on serving Updian's web interface on an untrusted network configure your web server or a WSGI container to serve it using the file updian.wsgi. For further information see Flask Deployment Options.

Example crontab entries

0 8 * * * /var/www/updian/updiancmd collect > /dev/null 2>&1 # (collect updates daily at 8 am)
0 9 * * * /var/www/updian/updiancmd update > /dev/null 2>&1 # (run updates daily at 9 am)

Example configuration using Apache HTTPd 2.x with mod_wsgi

To use mod_wsgi on the Apache2 web server you can use something along the following lines in your virtual host configuration (Assuming you installed Updian in /var/www/updian and want to serve it on http://host/updian):

<IfModule mod_wsgi.c>
    WSGIScriptAlias /updian /var/www/updian/updian.wsgi
    WSGIPassAuthorization On

    WSGIDaemonProcess updian-webif python-path=/var/www/updian home=/var/www/updian
    WSGIProcessGroup updian-webif

    # Add the following only if you installed via fabric
    # (i.e. you have a symlink called static in /var/www/updian).
    # It will serve static files directly via httpd.
    Alias /updian/static /var/www/updian/static

    <Directory /var/www/updian/static>
        Order allow,deny
        Allow from all
    </Directory>
</IfModule>

If you have installed Updian's dependencies into a virtual environment you should add its site-packages directory to the python-path of the daemon process:

WSGIDaemonProcess updian-webif python-path=/yourvenv/lib/python2.6/site-packages:/var/www/updian home=/var/www/updian

You can also use WSGIPythonHome to set an alternative Python interpreter for mod_wsgi to use globally (see: WSGIPythonHome documentation).

Updating from old server.txt format (used in UPDIAN v0.4 and older)

• Run updiancmd convert_sl
• For v0.5 only: Update your config.php to point to the newly created file

Checkrestart for updated services on remote machines

Since v0.3 Updian can check if there are services running on remote machines that need to be restartet. That is often needed if libs used by many programs (libssl i.e.) have been updated on the remote machine. After that it is i.e. required to restart apache or postfix.

Updian uses the script checkrestart from the package debian-goodies for that. Just apply apt-get install debian-goodies on the desired remote machines.

It does, in short, anything like this to find out which procs using deprecated libs: lsof -n | egrep -i "(DEL|inode)"

Updian writes the output from checkrestart to <server>_checkrestart.log (see "Logs" in webfrontend).

UPDIAN restricted shell - updian-rsh

Updian's default mode of operation gives the Updian server unlimited root access to all servers. updian-rsh is a shell script that can be used with ssh's forced command feature to limit the commands updian can execute over ssh. Then, even if the Updian server is compromised, the intruder can only do one thing with your other servers: Update them.

To use it, copy updian-rsh to the machines you want to update, for example to /usr/local/bin. Prefix the line in /root/.ssh/authorized_keys with

command="/usr/local/bin/updian-rsh"

so that it looks like this:

command="/usr/local/bin/updian-rsh" ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA8Yf[...]

Now when you try to connect to that server with ssh root@remote_server you should get the message

Updian Restriced Shell: Interactive shell not allowed

and the connection is closed.