Ubuntu: Installing MAAS

SSL Support

If you want secure access to your MAAS web UI/API, you need to do a few things. First, turn on SSL support in Apache:

$ sudo a2enmod ssl

Ensure that the Apache config file from etc/maas/maas-http.conf is included in /etc/apache2/conf.d/, then edit /etc/maas/maas_local_settings.py and change DEFAULT_MAAS_URL so that it uses https instead of http.

Now, restart Apache:

$ sudo service apache2 restart

At this point you will be able to access the MAAS web server using https but the default SSL certificate is insecure. Please generate your own and then edit /etc/apache2/conf.d/maas-http.conf to set the location of the certificate.

Choosing a series to install

You may have some specific reason to choose a particular version of Ubuntu to install on your nodes, perhaps based around package availability, hardware support or some other reason.

It is possible to choose a specific series from those available in a number of ways.

From the user interface

The web-based user interface makes it easy to select which Ubuntu series you wish to install on an individual node. When either adding a node manually, or on the node page when the node has been automatically discovered but before it is accepted, there is a drop down menu to select the version of Ubuntu you wish to install.

The menu will always list all the currently available series according to which boot images are available.

$ maas <profile> node update <system_id> distro_series="<value>"

Altering the Preseed file

When MAAS commissions a node it installs a version of Ubuntu. The installation is performed using a ‘preseed’ file, which is effectively a list of answers to the questions you would get were you to run the installer manually. The preseed file used by MAAS is carefully made so that the target node can be brought up and do all the jobs expected of it. However, in exceptional circumstances, you may wish to alter the pressed file to work around some issue. There are actually two preseed files, stored here:

/etc/maas/preseeds/generic
/etc/maas/preseeds/preseed-master

The generic file actually references the preseed-master file, and is used to set conditional parameters based on the type of series and architecture to install as well as to define the minimum set of install packages and to tidy up the PXE boot process if that has been used for the node. Unless you have a specific need to change where install packages come from, you should not need to edit this file.

For the more usual sorts of things you may wish to change, you should edit the preseed-master file. For example, depending on your network you may wish to change the clock settings:

# Local clock (set to UTC and use ntp)
d-i     clock-setup/utc boolean true
d-i     clock-setup/ntp boolean true
d-i     clock-setup/ntp-server  string ntp.ubuntu.com

Having consistent clocks is very important to the working of your MAAS system overall. If your nodes however cannot freely access the Internet, the supplied NTP server is not going to be very useful, and you may find it better to run an ntp service on the MAAS controller and change the ntp.ubuntu.com in the last line for a more appropriate server.

One thing you may wish to alter in the preseed file is the disk partitioning. This is a simple recipe that creates a swap partition and uses the rest of the disk for one large root filesystem:

partman-auto/text/atomic_scheme ::

500 10000 1000000 ext3
        $primary{ }
        $bootable{ }
        method{ format }
        format{ }
        use_filesystem{ }
        filesystem{ ext3 }
        mountpoint{ / } .

64 512 300% linux-swap
        method{ swap }
        format{ } .

Here the root partition must be at least 500 mb, and has effectively no maximum size. The swap partition ranges from 64 MB to 3 times the system’s ram. Adding $bootable{ } to make the partition bootable, and $primary{ } marks it as the primary partition. The other specifiers used are:

method{ format }

Used to make the partition be formatted. For swap partitions, change it to “swap”. To create a new partition but do not format it, change “format” to “keep” (such a partition can be used to reserve for future use some disk space).

format{ }

Also needed to make the partition be formatted.

use_filesystem{ }

Specifies that the partition has a filesystem on it.

filesystem{ ext3 }

Specifies the filesystem to put on the partition.

mountpoint{ / }

Where to mount the partition.

For more information on preseed options, you should refer to the official Ubuntu documentation