NAME
autoinstall —
unattended OpenBSD installation and
upgrade
DESCRIPTION
autoinstall allows unattended installation
or upgrade of OpenBSD by automatically responding to
installer questions with answers from a response file.
autoinstall uses DHCP to discover the location of
the response file and HTTP to fetch the file. If that fails, the installer
asks for the location which can either be a URL or a local path.
To start unattended installation or upgrade choose '(A)utoinstall' at the install prompt. If there is only one network interface, the installer fetches the response file via that interface. If there is more than one network interface, a selection is presented and the installer fetches the response file via the selected interface.
If the machine is netbooted, the
autoinstall feature is invoked if the user does not
intervene within a short time. It behaves as if the user selected
'(A)utoinstall', but always fetches the response file via the netboot
interface.
If either /auto_install.conf or
/auto_upgrade.conf is found on
bsd.rd's built-in RAM disk,
autoinstall behaves as if the machine is netbooted,
but uses the local response file. In case both files exist,
/auto_install.conf takes precedence.
autoinstall uses HTTP to fetch one of the
files install.conf,
MAC_address-install.conf or
hostname-install.conf for
install answers, or one of upgrade.conf,
MAC_address-upgrade.conf or
hostname-upgrade.conf for
upgrade answers. The URL used to fetch the file is constructed from
dhcpd.conf(5) statements extracted from the
dhclient(8) lease file. One of the statements
server-name, option
tftp-server-name, or next-server (in that
order of priority) specify the server. One of the
statements filename or option
bootfile-name (in that order of priority) specify the
filename. The statement option
host-name specifies the hostname which is also
used as the default hostname during installation.
If filename is
auto_install, then the URLs tried are, in order:
http://server/MAC_address-install.conf http://server/hostname-install.conf http://server/install.conf
where MAC_address is a string of six hex octets separated by colons representing the MAC address of the interface being used to fetch the files.
If filename is
auto_upgrade, the URLs tried are, in order:
http://server/MAC_address-upgrade.conf http://server/hostname-upgrade.conf http://server/upgrade.conf
On architectures where the filename
statement is used to provide the name of the file to netboot it is necessary
to create symbolic links called auto_install and
auto_upgrade that point to the expected boot program
and to change the value of the filename statement in
the dhcpd.conf(5) file to be auto_install
or auto_upgrade.
To use a subdirectory as response file location on the HTTP
server, the same directory structure containing the symbolic links has to
exist in the tftproot directory. The value of
filename has to be the full path to these symbolic
links, and the HTTP and TFTP servers must be on the same machine.
The response file is a line-oriented ASCII text file. The format of each line is:
question is an installer question (not
including the question mark) or a non-ambiguous part of it, consisting of
whitespace separated words. answer is the answer to
the question. Passwords may be in plaintext, encrypted with
encrypt(1), or set to
‘*************’ (13 '*'s) to disable
password logins, only permitting alternative access methods (for example,
ssh(1) keys).
If autoinstall does not find an answer in
the response file, the default answer as provided by the installer is
used.
The response file may contain answers to the following questions, which are only available during unattended installation to provide additional installer features:
- Public ssh key for root account = ssh key
- ssh key is stored in /root/.ssh/authorized_keys.
- Public ssh key for user puffy = ssh key
- ssh key is stored in ~puffy/.ssh/authorized_keys.
- URL to autopartitioning template for disklabel = url
- A template file for disklabel(8) autopartitioning is fetched from url allowing a custom partition layout for the root disk.
FILES
- /etc/dhcpd.conf
- dhcpd(8) configuration file
- install.conf
- response file for unattended installation
- upgrade.conf
- response file for unattended upgrade
EXAMPLES
A typical install.conf file will look something like this:
System hostname = server1 Password for root = $2b$14$Z4xRMg8vDpgYH...GVot3ySoj8yby Change the default console to com0 = yes Which speed should com0 use = 19200 Setup a user = puffy Password for user = ************* Public ssh key for user = ssh-ed25519 AAAAC3NzaC1...g3Aqre puffy@ai What timezone are you in = Europe/Stockholm Location of sets = http HTTP Server = cdn.openbsd.org
The same file could be used for upgrades by creating a symbolic link called upgrade.conf that points to install.conf. The upgrade process will only use the answers it needs.
And an example
dhcpd.conf(5) host declaration:
host foo {
hardware ethernet 00:50:60:49:8b:84;
fixed-address 192.168.2.180;
filename "auto_install";
option host-name "foo";
}
SEE ALSO
HISTORY
The autoinstall feature first appeared in
OpenBSD 5.5.
AUTHORS
Robert Peichaer <rpe@openbsd.org>