Headless Ubuntu
From charlesreid1
Contents
Overview
This page covers how to download, modify, and install a Ubuntu installation on a headless server using a Mac OS X to prepare the disk image.
To install Ubuntu on the headless server, I modified a Ubuntu install image to be a "No Questions Asked" installation - that is, install a minimal version of the operating system, and an SSH daemon. Once that's done, we can log in to the headless server and configure everything from there.
Mounting the Disk Image
I downloaded a disk image from http://xubuntu.org, since xubuntu is my favorite distro. The disk image went onto my Mac OS X. This was a .iso file.
However, Ubuntu distributes iso files that make Macs choke, so we have to modify the iso file slightly to be able to mount it and modify it on a Mac.
Creating a device from the iso file
We will use Disk Utility to try and mount the iso file. While the mount will fail, it will create a device that we can use to extract the contents of the Ubuntu iso file.
First, locate the iso file you downloaded. Right click on the file and pick Open With > Disk Utility.
Now locate the iso file on the left hand side of the window. Right click the iso file and select "Open Disk Image".
This will attempt to mount the drive, and will throw an error. However, you will see that there is an unmounted disk called "disk1s1" (or some variant of that). What we're going to do is turn that unmounted disk into a new iso file, and that new iso file will then be mountable on a Mac.
The /dev/disk1s1 is now a device, even though it is not mounted. Now we can interact with the device.
Turn the disk device into an extracted iso file
Now we run a command to turn the disk1s1 device into a new iso file using the dd command. Assuming you have downloaded your iso file to ~/Downloads, you would execute the following command:
dd if=/dev/disk1s1 of=/Users/charles/Downloads/xubuntu-extracted.iso bs=1m
We are specifying an input file (if) that is the device we mounted, which contains the contents of the Ubuntu installation. We are also specifying an output file (of) that is the "extracted" iso image. This extracted iso image will be mountable by Mac.
You should see some output like this:
$ dd if=/dev/disk1s1 of=./xubuntu-extracted.iso bs=1m 969+1 records in 969+1 records out 1017085952 bytes transferred in 75.963258 secs (13389183 bytes/sec)
Mount the extracted iso file
Now you can mount the extracted iso file, by double clicking it. You should be able to see all of the folders contained in the Ubuntu installer iso:
Modifying the Disk Image
Copying the iso contents
Because iso files are designed to be read-only file systems, and we want to modify the iso, we will need to copy all the data off the iso file, then modify the contents, then create a new iso file.
We can start by making a new folder on the hard drive and copying the contents of the disk (that came from the iso we mounted) into the folder.
Modifying the iso contents
We now modify the iso contents to make the installation CD install xubuntu by default (following instructions from here):
The file isolinux/txt.cfg contains the menu items that show up on boot. The file looks like this:
default live label live menu label ^Try Xubuntu without installing kernel /casper/vmlinuz append file=/cdrom/preseed/xubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- label live-install menu label ^Install Xubuntu kernel /casper/vmlinuz append file=/cdrom/preseed/xubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash --- label check menu label ^Check disc for defects kernel /casper/vmlinuz append boot=casper integrity-check initrd=/casper/initrd.lz quiet splash --- label memtest menu label Test ^memory kernel /install/mt86plus label hd menu label ^Boot from first hard disk localboot 0x80
These are modified to create a new menu item and make it the default:
default quiet label quiet menu label ^Install Xubuntu kernel /casper/vmlinuz append file=/cdrom/preseed/xubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash --- label live menu label ^Try Xubuntu without installing kernel /casper/vmlinuz append file=/cdrom/preseed/xubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --- label live-install menu label ^Install Xubuntu kernel /casper/vmlinuz append file=/cdrom/preseed/xubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash --- label check menu label ^Check disc for defects kernel /casper/vmlinuz append boot=casper integrity-check initrd=/casper/initrd.lz quiet splash --- label memtest menu label Test ^memory kernel /install/mt86plus label hd menu label ^Boot from first hard disk localboot 0x80
Creating a preseed file
Now create a preseed file, which allows you to automatically answer questions during the installation process, by copying the existing preseed file and modifying it. From the root of the Ubuntu disk image contents:
$ vim preseed/quiet.seed
Now modify quiet.seed based on the contents of the example preseed file on the ubuntu website:
https://help.ubuntu.com/12.04/installation-guide/example-preseed.txt
to get the final preseed file:
#### Contents of the preconfiguration file (for squeeze)
### Localization
# Preseeding only locale sets language, country and locale.
d-i debian-installer/locale string en_US
# The values can also be preseeded individually for greater flexibility.
d-i debian-installer/language string en
#d-i debian-installer/country string NL
#d-i debian-installer/locale string en_GB.UTF-8
# Optionally specify additional locales to be generated.
#d-i localechooser/supported-locales en_US.UTF-8, nl_NL.UTF-8
# Keyboard selection.
# Disable automatic (interactive) keymap detection.
d-i console-setup/ask_detect boolean false
#d-i keyboard-configuration/modelcode string pc105
d-i keyboard-configuration/layoutcode string us
# To select a variant of the selected layout (if you leave this out, the
# basic form of the layout will be used):
#d-i keyboard-configuration/variantcode string dvorak
### Network configuration
# Disable network configuration entirely. This is useful for cdrom
# installations on non-networked devices where the network questions,
# warning and long timeouts are a nuisance.
#d-i netcfg/enable boolean false
# netcfg will choose an interface that has link if possible. This makes it
# skip displaying a list if there is more than one interface.
d-i netcfg/choose_interface select auto
# To pick a particular interface instead:
#d-i netcfg/choose_interface select eth1
# If you have a slow dhcp server and the installer times out waiting for
# it, this might be useful.
d-i netcfg/dhcp_timeout string 60
# If you prefer to configure the network manually, uncomment this line and
# the static network configuration below.
#d-i netcfg/disable_autoconfig boolean true
# If you want the preconfiguration file to work on systems both with and
# without a dhcp server, uncomment these lines and the static network
# configuration below.
#d-i netcfg/dhcp_failed note
#d-i netcfg/dhcp_options select Configure network manually
# Static network configuration.
#d-i netcfg/get_nameservers string 192.168.1.1
#d-i netcfg/get_ipaddress string 192.168.1.42
#d-i netcfg/get_netmask string 255.255.255.0
#d-i netcfg/get_gateway string 192.168.1.1
#d-i netcfg/confirm_static boolean true
# Any hostname and domain names assigned from dhcp take precedence over
# values set here. However, setting the values still prevents the questions
# from being shown, even if values come from dhcp.
d-i netcfg/get_hostname string unassigned-hostname
d-i netcfg/get_domain string unassigned-domain
# Disable that annoying WEP key dialog.
d-i netcfg/wireless_wep string
# The wacky dhcp hostname that some ISPs use as a password of sorts.
#d-i netcfg/dhcp_hostname string radish
# If non-free firmware is needed for the network or other hardware, you can
# configure the installer to always try to load it, without prompting. Or
# change to false to disable asking.
#d-i hw-detect/load_firmware boolean true
### Network console
# Use the following settings if you wish to make use of the network-console
# component for remote installation over SSH. This only makes sense if you
# intend to perform the remainder of the installation manually.
#d-i anna/choose_modules string network-console
#d-i network-console/password password r00tme
#d-i network-console/password-again password r00tme
### Mirror settings
# If you select ftp, the mirror/country string does not need to be set.
#d-i mirror/protocol string ftp
d-i mirror/country string manual
d-i mirror/http/hostname string archive.ubuntu.com
d-i mirror/http/directory string /ubuntu
d-i mirror/http/proxy string
# Alternatively: by default, the installer uses CC.archive.ubuntu.com where
# CC is the ISO-3166-2 code for the selected country. You can preseed this
# so that it does so without asking.
#d-i mirror/http/mirror select CC.archive.ubuntu.com
# Suite to install.
#d-i mirror/suite string squeeze
# Suite to use for loading installer components (optional).
#d-i mirror/udeb/suite string squeeze
# Components to use for loading installer components (optional).
#d-i mirror/udeb/components multiselect main, restricted
### Clock and time zone setup
# Controls whether or not the hardware clock is set to UTC.
d-i clock-setup/utc boolean true
# You may set this to any valid setting for $TZ; see the contents of
# /usr/share/zoneinfo/ for valid values.
d-i time/zone string US/Eastern
# Controls whether to use NTP to set the clock during the install
d-i clock-setup/ntp boolean true
# NTP server to use. The default is almost always fine here.
#d-i clock-setup/ntp-server string ntp.example.com
### Partitioning
## Partitioning example
# If the system has free space you can choose to only partition that space.
# This is only honoured if partman-auto/method (below) is not set.
# Alternatives: custom, some_device, some_device_crypto, some_device_lvm.
#d-i partman-auto/init_automatically_partition select biggest_free
# Alternatively, you may specify a disk to partition. If the system has only
# one disk the installer will default to using that, but otherwise the device
# name must be given in traditional, non-devfs format (so e.g. /dev/hda or
# /dev/sda, and not e.g. /dev/discs/disc0/disc).
# For example, to use the first SCSI/SATA hard disk:
#d-i partman-auto/disk string /dev/sda
# In addition, you'll need to specify the method to use.
# The presently available methods are:
# - regular: use the usual partition types for your architecture
# - lvm: use LVM to partition the disk
# - crypto: use LVM within an encrypted partition
d-i partman-auto/method string lvm
# If one of the disks that are going to be automatically partitioned
# contains an old LVM configuration, the user will normally receive a
# warning. This can be preseeded away...
d-i partman-lvm/device_remove_lvm boolean true
# The same applies to pre-existing software RAID array:
d-i partman-md/device_remove_md boolean true
# And the same goes for the confirmation to write the lvm partitions.
d-i partman-lvm/confirm boolean true
# For LVM partitioning, you can select how much of the volume group to use
# for logical volumes.
#d-i partman-auto-lvm/guided_size string max
#d-i partman-auto-lvm/guided_size string 10GB
#d-i partman-auto-lvm/guided_size string 50%
# You can choose one of the three predefined partitioning recipes:
# - atomic: all files in one partition
# - home: separate /home partition
# - multi: separate /home, /usr, /var, and /tmp partitions
d-i partman-auto/choose_recipe select atomic
# Or provide a recipe of your own...
# If you have a way to get a recipe file into the d-i environment, you can
# just point at it.
#d-i partman-auto/expert_recipe_file string /hd-media/recipe
# If not, you can put an entire recipe into the preconfiguration file in one
# (logical) line. This example creates a small /boot partition, suitable
# swap, and uses the rest of the space for the root partition:
#d-i partman-auto/expert_recipe string \
# boot-root :: \
# 40 50 100 ext3 \
# $primary{ } $bootable{ } \
# method{ format } format{ } \
# use_filesystem{ } filesystem{ ext3 } \
# mountpoint{ /boot } \
# . \
# 500 10000 1000000000 ext3 \
# method{ format } format{ } \
# use_filesystem{ } filesystem{ ext3 } \
# mountpoint{ / } \
# . \
# 64 512 300% linux-swap \
# method{ swap } format{ } \
# .
# If you just want to change the default filesystem from ext3 to something
# else, you can do that without providing a full recipe.
#d-i partman/default_filesystem string ext4
# The full recipe format is documented in the file partman-auto-recipe.txt
# included in the 'debian-installer' package or available from D-I source
# repository. This also documents how to specify settings such as file
# system labels, volume group names and which physical devices to include
# in a volume group.
# This makes partman automatically partition without confirmation, provided
# that you told it what to do using one of the methods above.
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true
## Partitioning using RAID
# The method should be set to "raid".
#d-i partman-auto/method string raid
# Specify the disks to be partitioned. They will all get the same layout,
# so this will only work if the disks are the same size.
#d-i partman-auto/disk string /dev/sda /dev/sdb
# Next you need to specify the physical partitions that will be used.
#d-i partman-auto/expert_recipe string \
# multiraid :: \
# 1000 5000 4000 raid \
# $primary{ } method{ raid } \
# . \
# 64 512 300% raid \
# method{ raid } \
# . \
# 500 10000 1000000000 raid \
# method{ raid } \
# .
# Last you need to specify how the previously defined partitions will be
# used in the RAID setup. Remember to use the correct partition numbers
# for logical partitions. RAID levels 0, 1, 5, 6 and 10 are supported;
# devices are separated using "#".
# Parameters are:
# <raidtype> <devcount> <sparecount> <fstype> <mountpoint> \
# <devices> <sparedevices>
#d-i partman-auto-raid/recipe string \
# 1 2 0 ext3 / \
# /dev/sda1#/dev/sdb1 \
# . \
# 1 2 0 swap - \
# /dev/sda5#/dev/sdb5 \
# . \
# 0 2 0 ext3 /home \
# /dev/sda6#/dev/sdb6 \
# .
# For additional information see the file partman-auto-raid-recipe.txt
# included in the 'debian-installer' package or available from D-I source
# repository.
# This makes partman automatically partition without confirmation.
d-i partman-md/confirm boolean true
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true
## Controlling how partitions are mounted
# The default is to mount by UUID, but you can also choose "traditional" to
# use traditional device names, or "label" to try filesystem labels before
# falling back to UUIDs.
#d-i partman/mount_style select uuid
### Base system installation
# Configure APT to not install recommended packages by default. Use of this
# option can result in an incomplete system and should only be used by very
# experienced users.
#d-i base-installer/install-recommends boolean false
# The kernel image (meta) package to be installed; "none" can be used if no
# kernel is to be installed.
#d-i base-installer/kernel/image string linux-generic
### Account setup
# Skip creation of a root account (normal user account will be able to
# use sudo). The default is false; preseed this to true if you want to set
# a root password.
#d-i passwd/root-login boolean false
# Alternatively, to skip creation of a normal user account.
#d-i passwd/make-user boolean false
# Root password, either in clear text
#d-i passwd/root-password password r00tme
#d-i passwd/root-password-again password r00tme
# or encrypted using an MD5 hash.
#d-i passwd/root-password-crypted password [MD5 hash]
# To create a normal user account.
#d-i passwd/user-fullname string Ubuntu User
#d-i passwd/username string ubuntu
d-i passwd/user-fullname string user
d-i passwd/username string user
# Normal user's password, either in clear text
#d-i passwd/user-password password insecure
#d-i passwd/user-password-again password insecure
d-i passwd/user-password password changeme
d-i passwd/user-password-again password changeme
# or encrypted using an MD5 hash.
#d-i passwd/user-password-crypted password [MD5 hash]
# Create the first user with the specified UID instead of the default.
#d-i passwd/user-uid string 1010
# The installer will warn about weak passwords. If you are sure you know
# what you're doing and want to override it, uncomment this.
#d-i user-setup/allow-password-weak boolean true
# The user account will be added to some standard initial groups. To
# override that, use this.
#d-i passwd/user-default-groups string audio cdrom video
# Set to true if you want to encrypt the first user's home directory.
d-i user-setup/encrypt-home boolean false
### Apt setup
# You can choose to install restricted and universe software, or to install
# software from the backports repository.
#d-i apt-setup/restricted boolean true
#d-i apt-setup/universe boolean true
#d-i apt-setup/backports boolean true
# Uncomment this if you don't want to use a network mirror.
#d-i apt-setup/use_mirror boolean false
# Select which update services to use; define the mirrors to be used.
# Values shown below are the normal defaults.
#d-i apt-setup/services-select multiselect security
#d-i apt-setup/security_host string security.ubuntu.com
#d-i apt-setup/security_path string /ubuntu
# Additional repositories, local[0-9] available
#d-i apt-setup/local0/repository string \
# http://local.server/ubuntu squeeze main
#d-i apt-setup/local0/comment string local server
# Enable deb-src lines
#d-i apt-setup/local0/source boolean true
# URL to the public key of the local repository; you must provide a key or
# apt will complain about the unauthenticated repository and so the
# sources.list line will be left commented out
#d-i apt-setup/local0/key string http://local.server/key
# Enable extras.ubuntu.com.
d-i apt-setup/extras boolean true
# By default the installer requires that repositories be authenticated
# using a known gpg key. This setting can be used to disable that
# authentication. Warning: Insecure, not recommended.
#d-i debian-installer/allow_unauthenticated boolean true
### Package selection
tasksel tasksel/first multiselect xubuntu-desktop
# Individual additional packages to install
#d-i pkgsel/include string openssh-server build-essential
# Whether to upgrade packages after debootstrap.
# Allowed values: none, safe-upgrade, full-upgrade
#d-i pkgsel/upgrade select none
# Language pack selection
#d-i pkgsel/language-packs multiselect de, en, zh
# Policy for applying updates. May be "none" (no automatic updates),
# "unattended-upgrades" (install security updates automatically), or
# "landscape" (manage system with Landscape).
#d-i pkgsel/update-policy select none
# No XFCE translation packages yet.
d-i pkgsel/language-pack-patterns string
# Some versions of the installer can report back on what software you have
# installed, and what software you use. The default is not to report back,
# but sending reports helps the project determine what software is most
# popular and include it on CDs.
#popularity-contest popularity-contest/participate boolean false
# By default, the system's locate database will be updated after the
# installer has finished installing most packages. This may take a while, so
# if you don't want it, you can set this to "false" to turn it off.
#d-i pkgsel/updatedb boolean true
### Boot loader installation
# Grub is the default boot loader (for x86). If you want lilo installed
# instead, uncomment this:
#d-i grub-installer/skip boolean true
# To also skip installing lilo, and install no bootloader, uncomment this
# too:
#d-i lilo-installer/skip boolean true
# With a few exceptions for unusual partitioning setups, GRUB 2 is now the
# default. If you need GRUB Legacy for some particular reason, then
# uncomment this:
#d-i grub-installer/grub2_instead_of_grub_legacy boolean false
# This is fairly safe to set, it makes grub install automatically to the MBR
# if no other operating system is detected on the machine.
d-i grub-installer/only_debian boolean true
# This one makes grub-installer install to the MBR if it also finds some other
# OS, which is less safe as it might not be able to boot that other OS.
d-i grub-installer/with_other_os boolean true
# Alternatively, if you want to install to a location other than the mbr,
# uncomment and edit these lines:
#d-i grub-installer/only_debian boolean false
#d-i grub-installer/with_other_os boolean false
#d-i grub-installer/bootdev string (hd0,0)
# To install grub to multiple disks:
#d-i grub-installer/bootdev string (hd0,0) (hd1,0) (hd2,0)
# Optional password for grub, either in clear text
#d-i grub-installer/password password r00tme
#d-i grub-installer/password-again password r00tme
# or encrypted using an MD5 hash, see grub-md5-crypt(8).
#d-i grub-installer/password-crypted password [MD5 hash]
# Use the following option to add additional boot parameters for the
# installed system (if supported by the bootloader installer).
# Note: options passed to the installer will be added automatically.
#d-i debian-installer/add-kernel-opts string nousb
### Finishing up the installation
# During installations from serial console, the regular virtual consoles
# (VT1-VT6) are normally disabled in /etc/inittab. Uncomment the next
# line to prevent this.
#d-i finish-install/keep-consoles boolean true
# Avoid that last message about the install being complete.
d-i finish-install/reboot_in_progress note
# This will prevent the installer from ejecting the CD during the reboot,
# which is useful in some situations.
#d-i cdrom-detect/eject boolean false
# This is how to make the installer shutdown when finished, but not
# reboot into the installed system.
#d-i debian-installer/exit/halt boolean true
# This will power off the machine instead of just halting it.
#d-i debian-installer/exit/poweroff boolean true
### X configuration
# X can detect the right driver for some cards, but if you're preseeding,
# you override whatever it chooses. Still, vesa will work most places.
#xserver-xorg xserver-xorg/config/device/driver select vesa
# A caveat with mouse autodetection is that if it fails, X will retry it
# over and over. So if it's preseeded to be done, there is a possibility of
# an infinite loop if the mouse is not autodetected.
#xserver-xorg xserver-xorg/autodetect_mouse boolean true
# Monitor autodetection is recommended.
xserver-xorg xserver-xorg/autodetect_monitor boolean true
# Uncomment if you have an LCD display.
#xserver-xorg xserver-xorg/config/monitor/lcd boolean true
# X has three configuration paths for the monitor. Here's how to preseed
# the "medium" path, which is always available. The "simple" path may not
# be available, and the "advanced" path asks too many questions.
xserver-xorg xserver-xorg/config/monitor/selection-method \
select medium
xserver-xorg xserver-xorg/config/monitor/mode-list \
select 1024x768 @ 60 Hz
### Preseeding other packages
# Depending on what software you choose to install, or if things go wrong
# during the installation process, it's possible that other questions may
# be asked. You can preseed those too, of course. To get a list of every
# possible question that could be asked during an install, do an
# installation, and then run these commands:
# debconf-get-selections --installer > file
# debconf-get-selections >> file
#### Advanced options
### Running custom commands during the installation
# d-i preseeding is inherently not secure. Nothing in the installer checks
# for attempts at buffer overflows or other exploits of the values of a
# preconfiguration file like this one. Only use preconfiguration files from
# trusted locations! To drive that home, and because it's generally useful,
# here's a way to run any shell command you'd like inside the installer,
# automatically.
# This first command is run as early as possible, just after
# preseeding is read.
#d-i preseed/early_command string anna-install some-udeb
# This command is run immediately before the partitioner starts. It may be
# useful to apply dynamic partitioner preseeding that depends on the state
# of the disks (which may not be visible when preseed/early_command runs).
#d-i partman/early_command \
# string debconf-set partman-auto/disk "$(list-devices disk | head -n1)"
# This command is run just before the install finishes, but when there is
# still a usable /target directory. You can chroot to /target and use it
# directly, or use the apt-install and in-target commands to easily install
# packages and run commands in the target system.
#d-i preseed/late_command string apt-install zsh; in-target chsh -s /bin/zsh
|
Alrighty. Now we're ready to make an iso for installing our customized, No-Questions-Asked Xubuntu.
Creating the modified iso image
Our first step was to download the hybrid iso from Xubuntu.
Our second step was to extract the hybrid iso into a new iso that could be read by Mac.
Our third step was to modify the iso image.
Now we turn those modified files into an iso file using Disk Utility and hdiutil.
Create a burnable CD-R image from the folder containing the modified iso. Do this by opening Disk Utility and clicking File > New > Disk Image from Folder. Then select the folder with the iso contents.
This will create a .cdr image. This is the intermediate file.
To turn this intermediate .cdr image into an .iso file, use hdiutil. From the directory containing the .cdr file, execute the command:
$ hdiutil makehybrid -iso -joliet -o my-xubuntu.iso my-xubuntu.cdr
Putting the Disk Image on a USB
The last step is to take the modified .iso image, put it on a thumbdrive, and make a no-questions-asked thumbdrive xubuntu.
This is following this tutorial.
Convert iso to img
First, we convert the iso file to an img file:
$ hdiutil convert -format UDRW -o ./my-xubuntu.img ./my-xubuntu.iso $ mv my-xubuntu.img.dmg my-xubuntu.img
Mount your flashdrive device
Once you've inserted the flashdrive into the computer, you can run
$ diskutil list
and look for the device with the same size as your flash drive. This should be something like /dev/disk6.
Unmount this disk using the command:
$ diskutil unmountDisk /dev/disk6
This command unmounts the disk, but it does not unmount the device. What we'll do next is reformat the device using our modified Xubuntu iso file.
Format the flashdrive with the iso
We can format our disk with the dd utility:
$ sudo dd if=./my-xubuntu.img of=/dev/rdisk6 bs=1m
You can use either /dev/rdisk6 or /dev/disk6. This page says rdisk is faster.
That command will take a while, and the output will look something like this:
$ sudo dd if=./my-xubuntu.img of=/dev/rdisk4 bs=1m 969+1 records in 969+1 records out 1016520704 bytes transferred in 232.666302 secs (4369007 bytes/sec)
When it is done, eject your media with the command:
diskutil eject /dev/disk6
DO IT!!!
Now you're ready to install your no-questions-asked xubuntu install on your headless server with nothin' but a usb stick.