Deploying with anaconda deploy interface

Ironic supports deploying an OS with the anaconda installer. This anaconda deploy interface works with pxe and ipxe boot interfaces.

Configuration

The anaconda deploy interface is not enabled by default. To enable this, add anaconda to the value of the enabled_deploy_interfaces configuration option in ironic.conf. For example:

[DEFAULT]
...
enabled_deploy_interfaces = direct,anaconda
...

This change takes effect after all the ironic conductors have been restarted.

When creating an ironic node, specify anaconda as the deploy interface. For example:

baremetal node create --driver ipmi \
    --deploy-interface anaconda \
    --boot-interface ipxe

You can also set the anaconda deploy interface via --deploy-interface on an existing node:

baremetal node set <node> --deploy-interface anaconda

Creating an OS Image

While anaconda allows installing individual RPMs, the default kickstart file expects an OS tarball to be used as the OS image.

This baremetal.yum file contains all the yum/dnf commands that need to be run in order to generate the OS tarball. These commands install packages and package groups that need to be in the image:

group install 'Minimal Install'
install cloud-init
ts run

An OS tarball can be created using following set of commands, along with the above baremetal.yum file:

export CHROOT=/home/<user>/os-image
mkdir -p $(CHROOT)
mkdir -p $(CHROOT)/{dev,proc,run,sys}
chown -hR root:root $(CHROOT)
mount --bind /var/cache/yum $(CHROOT)/var/cache/yum
mount --bind /dev $(CHROOT)/dev
mount -t proc proc $(CHROOT)/proc
mount -t tmpfs tmpfs $(CHROOT)/run
mount -t sysfs sysfs $(CHROOT)/sys
dnf -y --installroot=$(CHROOT) makecache
dnf -y --installroot=$(CHROOT) shell baremetal.yum
rpm --root $(CHROOT) --import $(CHROOT)/etc/pki/rpm-gpg/RPM-GPG-KEY-*
truncate -s 0 $(CHROOT)/etc/machine-id
umount $(CHROOT)/var/cache/yum
umount $(CHROOT)/dev
umount $(CHROOT)/proc
umount $(CHROOT)/run
umount $(CHROOT)/sys
tar cpzf os-image.tar.gz --xattrs --acls --selinux -C $(CHROOT) .

Configuring the OS Image in glance

Anaconda is a two-stage installer – stage 1 consists of the kernel and ramdisk and stage 2 lives in a squashfs file. All these components can be found in the CentOS/RHEL/Fedora ISO images.

The kernel and ramdisk can be found at /images/pxeboot/vmlinuz and /images/pxeboot/initrd.img respectively in the ISO. The stage 2 squashfs image can be normally found at /LiveOS/squashfs.img or /images/install.img.

The OS tarball must be configured with the following properties in glance, in order to be used with the anaconda deploy driver:

  • kernel_id

  • ramdisk_id

  • stage2_id

This is an example of adding the anaconda-related images and the OS tarball to glance:

openstack image create --file ./vmlinuz --container-format aki \
    --disk-format aki --shared anaconda-kernel-<version>
openstack image create --file ./initrd.img --container-format ari \
    --disk-format ari --shared anaconda-ramdisk-<version>
openstack image create --file ./squashfs.img --container-format ari \
    --disk-format ari --shared anaconda-stage-<verison>
openstack image create --file ./os-image.tar.gz --container-format \
    compressed --disk-format raw --shared \
    --property kernel_id=<glance_uuid_vmlinuz> \
    --property ramdisk_id=<glance_uuid_ramdisk> \
    --property stage2_id=<glance_uuid_stage2> <disto-name-version>

Creating a bare metal server

Apart from uploading a custom kickstart template to glance and associating it with the OS image via the ks_template property in glance, operators can also set the kickstart template in the ironic node’s instance_info field. The kickstart template set in instance_info takes precedence over the one specified via the OS image in glance. If no kickstart template is specified (via the node’s instance_info or ks_template glance image property), the default kickstart template will be used to deploy the OS.

The default kickstart template is specified via the configuration option [anaconda]default_ks_template. It is set to this ks.cfg.template but can be modified to be some other template.

This is an example of how to set the kickstart template for a specific ironic node:

openstack baremetal node set <node> \
    --instance_info ks_template=glance://uuid

Limitations

This deploy interface has only been tested with Red Hat based operating systems that use anaconda. Other systems are not supported.