cobbler.conf - Man Page


cobbler.conf — Cobbler Configuration File Documentation

There are two main settings files which are located per default at /etc/cobbler/:


Since we are cleaning a lot of tech-debt this may change over time. We are trying to find the balance which format is the best for us to handle in the code and the best for admins to handle in the config files.


If you are using allow_dynamic_settings, then the comments in the YAML file will vanish after the first change due to the fact that PyYAML doesn't support comments (Source)

There are additional configuration file locations which need to follow the YAML Syntax. These are loaded from the include directory in the settings.yaml file. Any key specified in one of these files overwrites values from the main file.


When using allow_dynamic_settings the values are only persisted in the file settings.yaml. This may lead to a non expected behaviour after cobblerd restarts. This is a known issue.

Updates to the Yaml-Settings-File

Starting with 3.2.1:



If True, Cobbler will allow insertions of system records that duplicate the --dns-name information of other system records. In general, this is undesirable and should be left False.

default: False


If True, Cobbler will allow insertions of system records that duplicate the IP address information of other system records. In general, this is undesirable and should be left False.

default: False


If True, Cobbler will allow insertions of system records that duplicate the mac address information of other system records. In general, this is undesirable.

default: False


If True, Cobbler will allow settings to be changed dynamically without a restart of the cobblerd daemon. You can only change this variable by manually editing the settings file, and you MUST restart cobblerd after changing it.

default: False


Always write DHCP entries, regardless if netboot is enabled.

default: False


By default, installs are not set to send installation logs to the Cobbler server. With anamon_enabled, automatic installation templates may use the pre_anamon snippet to allow remote live monitoring of their installations from the Cobbler server. Installation logs will be stored under /var/log/cobbler/anamon/.


This does allow an XML-RPC call to send logs to this directory, without authentication, so enable only if you are ok with this limitation.

default: False


How long the authentication token is valid for, in seconds.

default: 3600


If using authn_pam in the modules.conf, this can be configured to change the PAM service authentication will be tested against.

default: "login"


This is a directory of files that Cobbler uses to make templating easier. See the Wiki for more information. Changing this directory should not be required.

default: /var/lib/cobbler/snippets


This is a directory of files that Cobbler uses to make templating easier. See the Wiki for more information. Changing this directory should not be required.

default: /var/lib/cobbler/templates


Set to path of bind chroot to create bind-chroot compatible bind configuration files. This should be automatically detected.

default: ""


Set to the ip address of the master bind DNS server for creating secondary bind configuration files.



Location of templates used for boot loader config generation.

default: "/etc/cobbler/boot_loader_conf"


The location where Cobbler searches for the bootloaders to copy into the web directory.

default: /var/lib/cobbler/loaders


The location where Cobbler searches for GRUB configuration files.

default: /var/lib/cobbler/grub_config


Email out a report when Cobbler finishes installing a system.

  • enabled: Set to true to turn this feature on
  • email: Which addresses to email
  • ignorelist: TODO
  • sender: Optional
  • smtp_server: Used to specify another server for an MTA.
  • subject: Use the default subject unless overridden.


build_reporting_enabled: false
build_reporting_sender: ""
build_reporting_email: [ 'root@localhost' ]
build_reporting_smtp_server: "localhost"
build_reporting_subject: ""
build_reporting_ignorelist: [ "" ]


Used for caching the intermediate files for ISO-Building. You may want to use a SSD, a tmpfs or something which does not persist across reboots and can be easily thrown away but is also fast.

default: /var/cache/cobbler/buildiso


If cache_enabled is True, a cache will keep converted records in memory to make checking them faster. This helps with use cases like writing out large numbers of records. There is a known issue with cache and remote XML-RPC API calls. If you will use Cobbler with config management or infrastructure-as-code tools such as Terraform, it is recommended to disable by setting to False.

default: True


Cheetah-language autoinstall templates can import Python modules. while this is a useful feature, it is not safe to allow them to import anything they want. This whitelists which modules can be imported through Cheetah. Users can expand this as needed but should never allow modules such as subprocess or those that allow access to the filesystem as Cheetah templates are evaluated by cobblerd as code.

  • random
  • re
  • time
  • netaddr


If set to True, all commands to the API (not directly to the XML-RPC server) will go over HTTPS instead of plain text. Be sure to change the http_port setting to the correct value for the web server.

default: False


If set to True, all commands will be forced to use the localhost address instead of using the above value which can force commands like cobbler sync to open a connection to a remote address if one is in the configuration and would traceback.

default: False


Used for replicating the Cobbler instance.

default: ""


Convert hostnames to IP addresses (where possible) so DNS isn't a requirement for various tasks to work correctly.

default: False


Default createrepo_flags to use for new repositories.

default: "-c cache -s sha"


If no autoinstall template is specified to profile add, use this template.

default: /var/lib/cobbler/templates/default.ks


Configure all installed systems to use these name servers by default unless defined differently in the profile. For DHCP configurations you probably do not want to supply this.


default_name_servers: []
default_name_servers_search: []


if using the authz_ownership module, objects created without specifying an owner are assigned to this owner and/or group.

  • admin


Cobbler has various sample automatic installation templates stored in /var/lib/cobbler/templates/. This controls what install (root) password is set up for those systems that reference this variable. The factory default is "cobbler" and Cobbler check will warn if this is not changed. The simplest way to change the password is to run openssl passwd -1 and put the output between the "".

default: "$1$mF86/UHC$WvcIcX2t6crBz2onWxyac."


The default template type to use in the absence of any other detected template. If you do not specify the template with #template=<template_type> on the first line of your templates/snippets, Cobbler will assume try to use the following template engine to parse the templates.


Over time we will try to deprecate and remove Cheetah3 as a template engine. It is hard to package and there are fewer guides then with Jinja2. Making the templating independent of the engine is a task which complicates the code. Thus, please try to use Jinja2. We will try to support a seamless transition on a best-effort basis.

Current valid values are: cheetah, jinja2

default: "cheetah"


For libvirt based installs in Koan, if no virt-bridge is specified, which bridge do we try? For EL 4/5 hosts this should be xenbr0, for all versions of Fedora, try virbr0. This can be overridden on a per-profile basis or at the Koan command line though this saves typing to just set it here to the most common option.

default: xenbr0


The on-disk format for the virtualization disk.

default: raw


Use this as the default disk size for virt guests (GB).

default: 5


Use this as the default memory size for virt guests (MB).

default: 512


If Koan is invoked without --virt-type and no virt-type is set on the profile/system, what virtualization type should be assumed?

Current valid values are:

  • xenpv
  • xenfv
  • qemu
  • vmware

NOTE: this does not change what virt_type is chosen by import.

default: xenpv


Enable gPXE booting? Enabling this option will cause Cobbler to copy the undionly.kpxe file to the TFTP root directory, and if a profile/system is configured to boot via gPXE it will chain load off pxelinux.0.


We now gPXE is not active anymore and try to transition the code, settings and guide we have to iPXE.

default: False


Controls whether Cobbler will add each new profile entry to the default PXE boot menu. This can be over-ridden on a per-profile basis when adding/editing profiles with --enable-menu=False/True. Users should ordinarily leave this setting enabled unless they are concerned with accidental reinstall from users who select an entry at the PXE boot menu. Adding a password to the boot menus templates may also be a good solution to prevent unwanted reinstallations.

default: True


Change this port if Apache is not running plain text on port 80. Most people can leave this alone.

default: 80


Include other configuration snippets with this regular expression. This is a list of folders.

default: [ "/etc/cobbler/settings.d/*.settings" ]


Folder to search for the ISO templates. These will build the boot-menu of the built ISO.

default: /etc/cobbler/iso


This is a directory of files that Cobbler uses to include files into Jinja2 templates. Per default this settings is commented out.

default: /var/lib/cobbler/jinja2


Kernel options that should be present in every Cobbler installation. Kernel options can also be applied at the distro/profile/system level.

default: {}


Configuration options if using the authn_ldap module. See the Wiki for details. This can be ignored if you are not using LDAP for WebUI/XML-RPC authentication.


ldap_server: ""
ldap_base_dn: "DC=example,DC=com"
ldap_port: 389
ldap_tls: true
ldap_anonymous_bind: true
ldap_search_bind_dn: ''
ldap_search_passwd: ''
ldap_search_prefix: 'uid='
ldap_tls_cacertfile: ''
ldap_tls_keyfile: ''
ldap_tls_certfile: ''


When using the Bind9 DNS server, you can enable or disable if the BMCs should receive own DNS entries.

default: False


Set to True to enable Cobbler's DHCP management features. The choice of DHCP management engine is in /etc/cobbler/modules.conf.

default: True


Set to True to enable Cobbler's DNS management features. The choice of DNS management engine is in /etc/cobbler/modules.conf.

default: False


If using BIND (named) for DNS management in /etc/cobbler/modules.conf and manage_dns is enabled (above), this lists which zones are managed. See dns-management for more information.


manage_forward_zones: []
manage_reverse_zones: []


Whether or not to manage the genders file. For more information on that visit:

default: False


Set to True to enable Cobbler's RSYNC management features.

default: False


Set to True to enable Cobbler's TFTP management features. The choice of TFTP management engine is in /etc/cobbler/modules.conf.

default: True


Cobbler has a feature that allows for integration with config management systems such as Puppet. The following parameters work in conjunction with --mgmt-classes and are described in further detail at configuration-management.

mgmt_classes: []
    from_cobbler: true


If using Cobbler with manage_dhcp, put the IP address of the Cobbler server here so that PXE booting guests can find it. If you do not set this correctly, this will be manifested in TFTP open timeouts.



This enables or disables the replacement (or removal) of records in the DNS zone for systems created (or removed) by Cobbler.


There are additional settings needed when enabling this. Due to the limited number of resources, this won't be done until 3.3.0. Thus please expect to run into troubles when enabling this setting.

default: False


The logfile to document what records are added or removed in the DNS zone for systems.


The functionality this settings is related to is currently not tested due to tech-debt. Please use it with caution. This note will be removed once we were able to look deeper into this functionality of Cobbler.

  • Required: No
  • Default: /var/log/cobbler/nsupdate.log



The functionality this settings is related to is currently not tested due to tech-debt. Please use it with caution. This note will be removed once we were able to look deeper into this functionality of Cobbler.

  • Required: No
  • Default: hmac-sha512



The functionality this settings is related to is currently not tested due to tech-debt. Please use it with caution. This note will be removed once we were able to look deeper into this functionality of Cobbler.

  • Required: No
  • Default: []


Settings for power management features. These settings are optional. See power-management to learn more.

Choices (refer to the fence-agents project for a complete list):

  • apc_snmp
  • bladecenter
  • bullpap
  • drac
  • ether_wake
  • ilo
  • integrity
  • ipmilan
  • ipmilanplus
  • lpar
  • rsa
  • virsh
  • wti

default: ipmilanplus


External proxy which is used by the following commands: get-loaders, reposync, signature update




Internal proxy which is used by systems to reach Cobbler for kickstarts.

e.g.: proxy_url_int:

default: ""


If enabled, this setting ensures that puppet is installed during machine provision, a client certificate is generated and a certificate signing request is made with the puppet master server.

default: False


Choose whether to enable puppet parameterized classes or not. Puppet versions prior to 2.6.5 do not support parameters.

default: True


Choose a --server argument when running puppetd/puppet agent during autoinstall.

default: 'puppet'


Let Cobbler know that you're using a newer version of puppet. Choose version 3 to use: 'puppet agent'; version 2 uses status quo: 'puppetd'.

default: 2


Location of the puppet executable, used for revoking certificates.

default: "/usr/bin/puppet"


If this setting is set to True, Cobbler systems that pxe boot will request at the end of their installation to toggle the --netboot-enabled record in the Cobbler system record. This eliminates the potential for a PXE boot loop if the system is set to PXE first in it's BIOS order. Enable this if PXE is first in your BIOS boot order, otherwise leave this disabled. See the manpage for --netboot-enabled.

default: True


If this setting is set to True, triggers will be executed when systems will request to toggle the --netboot-enabled record at the end of their installation.

default: True


If using authn_spacewalk in modules.conf to let Cobbler authenticate against Satellite/Spacewalk's auth system, by default it will not allow per user access into Cobbler Web and Cobbler XML-RPC. In order to permit this, the following setting must be enabled HOWEVER doing so will permit all Spacewalk/Satellite users of certain types to edit all of Cobbler's configuration. these roles are: config_admin and org_admin. Users should turn this on only if they want this behavior and do not have a cross-multi-org separation concern. If you have a single org in your satellite, it's probably safe to turn this on and then you can use CobblerWeb alongside a Satellite install.

default: False


This setting is only used by the code that supports using Uyuni/SUSE Manager/Spacewalk/Satellite authentication within Cobbler Web and Cobbler XML-RPC.

default: ""


Specify the default Red Hat authorization key to use to register system. If left blank, no registration will be attempted. Similarly you can set the --redhat-management-key to blank on any system to keep it from trying to register.

default: ""


If set to True, allows /usr/bin/cobbler-register (part of the Koan package) to be used to remotely add new Cobbler system records to Cobbler. This effectively allows for registration of new hardware from system records.

default: False


When a puppet managed machine is reinstalled it is necessary to remove the puppet certificate from the puppet master server before a new certificate is signed (see above). Enabling the following feature will ensure that the certificate for the machine to be installed is removed from the puppet master server if the puppet master server is running on the same machine as Cobbler. This requires puppet_auto_setup above to be enabled

default: False


Replication rsync options for repos set to override default value of -avzH.

default: "-avzH"


replication rsync options for distros, autoinstalls, snippets set to override default value of -avzH.

default: "-avzH"


Flags to use for yum's reposync. If your version of yum reposync does not support -l, you may need to remove that option.

default: "-l -n -d"


Flags to use for rysync's reposync. If archive mode (-a,--archive) is used then createrepo is not ran after the rsync as it pulls down the repodata as well. This allows older OS's to mirror modular repos using rsync.

default: "-rltDv --copy-unsafe-links"


When DHCP and DNS management are enabled, cobbler sync can automatically restart those services to apply changes. The exception for this is if using ISC for DHCP, then OMAPI eliminates the need for a restart. omapi, however, is experimental and not recommended for most configurations. If DHCP and DNS are going to be managed, but hosted on a box that is not on this server, disable restarts here and write some other script to ensure that the config files get copied/rsynced to the destination box. This can be done by modifying the restart services trigger. Note that if manage_dhcp and manage_dns are disabled, the respective parameter will have no effect. Most users should not need to change this.


restart_dns: true
restart_dhcp: true


Install triggers are scripts in /var/lib/cobbler/triggers/install that are triggered in autoinstall pre and post sections. Any executable script in those directories is run. They can be used to send email or perform other actions. They are currently run as root so if you do not need this functionality you can disable it, though this will also disable cobbler status which uses a logging trigger to audit install progress.

default: true


enables a trigger which version controls all changes to /var/lib/cobbler when add, edit, or sync events are performed. This can be used to revert to previous database versions, generate RSS feeds, or for other auditing or backup purposes. Git and Mercurial are currently supported, but Git is the recommend SCM for use with this feature.


scm_track_enabled: false
scm_track_mode: "git"
scm_track_author: "cobbler <cobbler@localhost>"
scm_push_script: "/bin/true"


Sort and indent JSON output to make it more human-readable.

default: False


This is the address of the Cobbler server -- as it is used by systems during the install process, it must be the address or hostname of the system as those systems can see the server. if you have a server that appears differently to different subnets (dual homed, etc), you need to read the --server-override section of the manpage for how that works.



When puppet starts on a system after installation it needs to have its certificate signed by the puppet master server. Enabling the following feature will ensure that the puppet server signs the certificate after installation if the puppet master server is running on the same machine as Cobbler. This requires puppet_auto_setup above to be enabled.

default: false


The cobbler import workflow is powered by this file. Its location can be set with this config option.

default: /var/lib/cobbler/distro_signatures.json


Updates to the signatures may happen more often then we have releases. To enable you to import new version we provide the most up to date signatures we offer on this like. You may host this file for yourself and adjust it for your needs.



This variable contains the location of the tftpboot directory. If this directory is not present Cobbler does not start.

Default: /srv/tftpboot


Should new profiles for virtual machines default to auto booting with the physical host when the physical host reboots? This can be overridden on each profile or system object.

default: true


Cobbler's web directory.  Don't change this setting -- see the Wiki on "relocating your Cobbler install" if your /var partition is not large enough.

default: @@webroot@@/cobbler


Directories that will not get wiped and recreated on a cobbler sync.


  - misc
  - web
  - webui
  - localmirror
  - repo_mirror
  - distro_mirror
  - images
  - links
  - pub
  - repo_profile
  - repo_system
  - svc
  - rendered
  - .link_cache


Cobbler's public XML-RPC listens on this port. Change this only if absolutely needed, as you'll have to start supplying a new port option to Koan if it is not the default.

default: 25151


The default yum priority for all the distros. This is only used if yum-priorities plugin is used. 1 is the maximum value. Tweak with caution.

default: true


cobbler repo add commands set Cobbler up with repository information that can be used during autoinstall and is automatically set up in the Cobbler autoinstall templates. By default, these are only available at install time. To make these repositories usable on installed systems (since Cobbler makes a very convenient mirror) set this to True. Most users can safely set this to True. Users who have a dual homed Cobbler server, or are installing laptops that will not always have access to the Cobbler server may wish to leave this as False. In that case, the Cobbler mirrored yum repos are still accessible at and YUM configuration can still be done manually. This is just a shortcut.

default: True


Flags to use for yumdownloader. Not all versions may support --resolve.

default: "--resolve"


If you have own custom modules which are not shipped with Cobbler directly you may have additional sections here.


What users can log into the WebUI and Read-Write XML-RPC?


  • authn_denyall    -- no one (default)
  • authn_configfile -- use /etc/cobbler/users.digest (for basic setups)
  • authn_passthru   -- ask Apache to handle it (used for kerberos)
  • authn_ldap       -- authenticate against LDAP
  • authn_spacewalk  -- ask Spacewalk/Satellite (experimental)
  • authn_pam        -- use PAM facilities
  • authn_testing    -- username/password is always testing/testing (debug)
  • (user supplied)  -- you may write your own module

WARNING: this is a security setting, do not choose an option blindly.

For more information:

default: authn_configfile


Once a user has been cleared by the WebUI/XML-RPC, what can they do?


  • authz_allowall   -- full access for all authenticated users (default)
  • authz_ownership  -- use users.conf, but add object ownership semantics
  • (user supplied)  -- you may write your own module

WARNING: this is a security setting, do not choose an option blindly. If you want to further restrict Cobbler with ACLs for various groups, pick authz_ownership.  authz_allowall does not support ACLs. Configuration file does but does not support object ownership which is useful as an additional layer of control.

For more information:

default: authz_allowall


Chooses the DNS management engine if manage_dns is enabled in /etc/cobbler/settings.yaml, which is off by default.


  • manage_bind    -- default, uses BIND/named
  • manage_dnsmasq -- uses dnsmasq, also must select dnsmasq for DHCP below
  • manage_ndjbdns -- uses ndjbdns

NOTE: More configuration is still required in /etc/cobbler

For more information see dns-management.

default: manage_bind


Chooses the DHCP management engine if manage_dhcp is enabled in /etc/cobbler/settings.yaml, which is off by default.


  • manage_isc     -- default, uses ISC dhcpd
  • manage_dnsmasq -- uses dnsmasq, also must select dnsmasq for DNS above

NOTE: More configuration is still required in /etc/cobbler

For more information see dhcp-management.

default: manage_isc


Chooses the TFTP management engine if manage_tftpd is enabled in /etc/cobbler/settings.yaml, which is on by default.


  • manage_in_tftpd -- default, uses the system's TFTP server
  • manage_tftpd_py -- uses Cobbler's TFTP server

default: manage_in_tftpd


Enno Gotthold


Nov 22, 2021 3.2 Cobbler