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PXE Boot Install

Starting from version 0.2.0, Harvester can be installed in a mass manner. This document provides an example to do the automatic installation with PXE boot.

We recommend using iPXE to perform the network boot. It has more features than the traditional PXE Boot program and is likely available in modern NIC cards. If NIC cards don't come with iPXE firmware, iPXE firmware images can be loaded from the TFTP server first.

To see sample iPXE scripts, please visit Harvester iPXE Examples.

Preparing HTTP Servers

An HTTP server is required to serve boot files. Please ensure these servers are set up correctly before continuing.

Let's assume an NGINX HTTP server's IP is 10.100.0.10, and it serves /usr/share/nginx/html/ folder at the path http://10.100.0.10/.

Preparing Boot Files

  • Download the required files from Harvester Releases Page. Choose an appropriate version.

  • The ISO: harvester-amd64.iso

  • The kernel: harvester-vmlinuz-amd64
  • The initrd: harvester-initrd-amd64

  • Serve the files.

Copy or move the downloaded files to an appropriate location so they can be downloaded via the HTTP server. e.g.,

sudo mkdir -p /usr/share/nginx/html/harvester/
sudo cp /path/to/harvester-amd64.iso /usr/share/nginx/html/harvester/
sudo cp /path/to/harvester-vmlinuz-amd64 /usr/share/nginx/html/harvester/
sudo cp /path/to/harvester-initrd-amd64 /usr/share/nginx/html/harvester/

Preparing iPXE boot scripts

When performing automatic installation, there are two modes:

  • CREATE: we are installing a node to construct an initial Harvester cluster.
  • JOIN: we are installing a node to join an existing Harvester cluster.

Prerequisite

Nodes need to have at least 8G of RAM because the full ISO file is loaded into tmpfs during the installation.

CREATE mode

Warning

Security Risks: The configuration file below contains credentials which should be kept secretly. Please do not make the configuration file publicly accessible at the moment.

Create a Harvester configuration file config-create.yaml for CREATE mode. Modify the values as needed:

# cat /usr/share/nginx/html/harvester/config-create.yaml
token: token
os:
  hostname: node1
  ssh_authorized_keys:
  - ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQDbeUa9A7Kee+hcCleIXYxuaPksn2m4PZTd4T7wPcse8KbsQfttGRax6vxQXoPO6ehddqOb2nV7tkW2mEhR50OE7W7ngDHbzK2OneAyONYF44bmMsapNAGvnsBKe9rNrev1iVBwOjtmyVLhnLrJIX+2+3T3yauxdu+pmBsnD5OIKUrBrN1sdwW0rA2rHDiSnzXHNQM3m02aY6mlagdQ/Ovh96h05QFCHYxBc6oE/mIeFRaNifa4GU/oELn3a6HfbETeBQz+XOEN+IrLpnZO9riGyzsZroB/Y3Ju+cJxH06U0B7xwJCRmWZjuvfFQUP7RIJD1gRGZzmf3h8+F+oidkO2i5rbT57NaYSqkdVvR6RidVLWEzURZIGbtHjSPCi4kqD05ua8r/7CC0PvxQb1O5ILEdyJr2ZmzhF6VjjgmyrmSmt/yRq8MQtGQxyKXZhJqlPYho4d5SrHi5iGT2PvgDQaWch0I3ndEicaaPDZJHWBxVsCVAe44Wtj9g3LzXkyu3k= [email protected]
  password: rancher
install:
  mode: create
  mgmt_interface: eth0
  device: /dev/sda
  iso_url: http://10.100.0.10/harvester-amd64.iso

For machines that needs to be installed as CREATE mode, the following is an iPXE script that boots the kernel with the above config:

#!ipxe
kernel vmlinuz k3os.mode=install console=ttyS0 console=tty1 harvester.install.automatic=true harvester.install.config_url=http://10.100.0.10/harvester/config-create.yaml
initrd initrd
boot

Let's assume the iPXE script is stored in /usr/share/nginx/html/harvester/ipxe-create

JOIN mode

Warning

Security Risks: The configuration file below contains credentials which should be kept secretly. Please do not make the configuration file publicly accessible at the moment.

Create a Harvester configuration file config-join.yaml for JOIN mode. Modify the values as needed:

# cat /usr/share/nginx/html/harvester/config-join.yaml
server_url: https://10.100.0.130:6443
token: token
os:
  hostname: node2
  ssh_authorized_keys:
  - ssh-rsa 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 [email protected]
  dns_nameservers:
  - 1.1.1.1
  - 8.8.8.8
  password: rancher
install:
  mode: join
  mgmt_interface: eth0
  device: /dev/sda
  iso_url: http://10.100.0.10/harvester/harvester-amd64.iso

Note that the mode is join and the server_url needs to be provided.

For machines that needs to be installed in JOIN mode, the following is an iPXE script that boots the kernel with the above config:

#!ipxe
kernel vmlinuz k3os.mode=install console=ttyS0 console=tty1 harvester.install.automatic=true harvester.install.config_url=http://10.100.0.10/harvester/config-join.yaml
initrd initrd
boot

Let's assume the iPXE script is stored in /usr/share/nginx/html/harvester/ipxe-join.

TROUBLESHOOTING

  • Sometimes the installer might be not able to fetch the Harvester configuration file because the network stack is not ready yet. To work around this, please add a boot_cmd parameter to the iPXE script, e.g.,
#!ipxe
kernel vmlinuz k3os.mode=install console=ttyS0 console=tty1 harvester.install.automatic=true harvester.install.config_url=http://10.100.0.10/harvester/config-join.yaml boot_cmd="echo include_ping_test=yes >> /etc/conf.d/net-online"
initrd initrd
boot

DHCP server configuration

Here is an example to configure the ISC DHCP server to offer iPXE scripts:

option architecture-type code 93 = unsigned integer 16;

subnet 10.100.0.0 netmask 255.255.255.0 {
    option routers 10.100.0.10;
        option domain-name-servers 192.168.2.1;
    range 10.100.0.100 10.100.0.253;
}

group {
  # create group
  if exists user-class and option user-class = "iPXE" {
    # iPXE Boot
    if option architecture-type = 00:07 {
      filename "http://10.100.0.10/harvester/ipxe-create-efi";
    } else {
      filename "http://10.100.0.10/harvester/ipxe-create";
    }
  } else {
    # PXE Boot
    if option architecture-type = 00:07 {
      # UEFI
      filename "ipxe.efi";
    } else {
      # Non-UEFI
      filename "undionly.kpxe";
    }
  }

  host node1 { hardware ethernet 52:54:00:6b:13:e2; }
}


group {
  # join group
  if exists user-class and option user-class = "iPXE" {
    # iPXE Boot
    if option architecture-type = 00:07 {
      filename "http://10.100.0.10/harvester/ipxe-join-efi";
    } else {
      filename "http://10.100.0.10/harvester/ipxe-join";
    }
  } else {
    # PXE Boot
    if option architecture-type = 00:07 {
      # UEFI
      filename "ipxe.efi";
    } else {
      # Non-UEFI
      filename "undionly.kpxe";
    }
  }

  host node2 { hardware ethernet 52:54:00:69:d5:92; }
}

The config file declares a subnet and two groups. The first group is for hosts to boot with CREATE mode and the other one is for JOIN mode. By default, the iPXE path is chosen, but if it sees a PXE client, it also offers the iPXE image according to client architecture. Please prepare those images and a tftp server first.

Harvester configuration

For more information about Harvester configuration, please refer to the Harvester configuration.

Users can also provide configuration via kernel parameters. For example, to specify the CREATE install mode, the user can pass the harvester.install.mode=create kernel parameter when booting. Values passed through kernel parameters have higher priority than values specified in the config file.

UEFI HTTP Boot support

UEFI firmware supports loading a boot image from HTTP server. This section demonstrates how to use UEFI HTTP boot to load the iPXE program and perform the automatic installation.

Serve the iPXE program

Download the iPXE uefi program from http://boot.ipxe.org/ipxe.efi and make ipxe.efi can be downloaded from the HTTP server. e.g.:

cd /usr/share/nginx/html/harvester/
wget http://boot.ipxe.org/ipxe.efi

The file now can be downloaded from http://10.100.0.10/harvester/ipxe.efi

DHCP server configuration

If the user plans to use the UEFI HTTP boot feature by getting a dynamic IP first, the DHCP server needs to provides the iPXE program URL when it sees such a request. Here is an updated ISC DHCP server group example:

group {
  # create group
  if exists user-class and option user-class = "iPXE" {
    # iPXE Boot
    if option architecture-type = 00:07 {
      filename "http://10.100.0.10/harvester/ipxe-create-efi";
    } else {
      filename "http://10.100.0.10/harvester/ipxe-create";
    }
  } elsif substring (option vendor-class-identifier, 0, 10) = "HTTPClient" {
    # UEFI HTTP Boot
    option vendor-class-identifier "HTTPClient";
    filename "http://10.100.0.10/harvester/ipxe.efi";
  } else {
    # PXE Boot
    if option architecture-type = 00:07 {
      # UEFI
      filename "ipxe.efi";
    } else {
      # Non-UEFI
      filename "undionly.kpxe";
    }
  }

  host node1 { hardware ethernet 52:54:00:6b:13:e2; }
}

The elsif substring statement is new, and it offers http://10.100.0.10/harvester/ipxe.efi when it sees a UEFI HTTP boot DHCP request. After the client fetches the iPXE program and runs it, the iPXE program will send a DHCP request again and load the iPXE script from URL http://10.100.0.10/harvester/ipxe-create-efi.

The iPXE script for UEFI boot

It's mandatory to specify the initrd image for UEFI boot in the kernel parameters. Here is an updated version of iPXE script for CREATE mode.

#!ipxe
kernel vmlinuz initrd=initrd k3os.mode=install console=ttyS0 console=tty1 harvester.install.automatic=true harvester.install.config_url=http://10.100.0.10/harvester/config-create.yaml
initrd initrd
boot

The parameter initrd=initrd is required for initrd to be chrooted.