BootConfig

The boot configuration is very important: boot_command specifies the keys to type when the virtual machine is first booted in order to start the OS installer. This command is typed after boot_wait, which gives the virtual machine some time to actually load.

The boot_command is an array of strings. The strings are all typed in sequence. It is an array only to improve readability within the template.

There are a set of special keys available. If these are in your boot command, they will be replaced by the proper key:

• <bs> - Backspace

• <del> - Delete

• <enter> <return> - Simulates an actual "enter" or "return" keypress.

• <esc> - Simulates pressing the escape key.

• <tab> - Simulates pressing the tab key.

• <f1> - <f12> - Simulates pressing a function key.

• <up> <down> <left> <right> - Simulates pressing an arrow key.

• <spacebar> - Simulates pressing the spacebar.

• <insert> - Simulates pressing the insert key.

• <home> <end> - Simulates pressing the home and end keys.

• <pageUp> <pageDown> - Simulates pressing the page up and page down keys.

• <menu> - Simulates pressing the Menu key.

• <leftAlt> <rightAlt> - Simulates pressing the alt key.

• <leftCtrl> <rightCtrl> - Simulates pressing the ctrl key.

• <leftShift> <rightShift> - Simulates pressing the shift key.

• <leftSuper> <rightSuper> - Simulates pressing the ⌘ or Windows key.

• <wait> <wait5> <wait10> - Adds a 1, 5 or 10 second pause before sending any additional keys. This is useful if you have to generally wait for the UI to update before typing more.

• <waitXX> - Add an arbitrary pause before sending any additional keys. The format of XX is a sequence of positive decimal numbers, each with optional fraction and a unit suffix, such as 300ms, 1.5h or 2h45m. Valid time units are ns, us (or µs), ms, s, m, h. For example <wait10m> or <wait1m20s>.

• <XXXOn> <XXXOff> - Any printable keyboard character, and of these "special" expressions, with the exception of the <wait> types, can also be toggled on or off. For example, to simulate ctrl+c, use <leftCtrlOn>c<leftCtrlOff>. Be sure to release them, otherwise they will be held down until the machine reboots. To hold the c key down, you would use <cOn>. Likewise, <cOff> to release.

• {{ .HTTPIP }} {{ .HTTPPort }} - The IP and port, respectively of an HTTP server that is started serving the directory specified by the http_directory configuration parameter. If http_directory isn't specified, these will be blank!

• {{ .Name }} - The name of the VM.

Example boot command. This is actually a working boot command used to start an CentOS 6.4 installer:

In JSON:

"boot_command": [
    "<tab><wait>",
    " ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/centos6-ks.cfg<enter>"
 ]

In HCL2:

boot_command = [
    "<tab><wait>",
    " ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/centos6-ks.cfg<enter>"
 ]

The example shown below is a working boot command used to start an Ubuntu 12.04 installer:

In JSON:

"boot_command": [
  "<esc><esc><enter><wait>",
  "/install/vmlinuz noapic ",
  "preseed/url=http://{{ .HTTPIP }}:{{ .HTTPPort }}/preseed.cfg ",
  "debian-installer=en_US auto locale=en_US kbd-chooser/method=us ",
  "hostname={{ .Name }} ",
  "fb=false debconf/frontend=noninteractive ",
  "keyboard-configuration/modelcode=SKIP keyboard-configuration/layout=USA ",
  "keyboard-configuration/variant=USA console-setup/ask_detect=false ",
  "initrd=/install/initrd.gz -- <enter>"
]

In HCL2:

boot_command = [
  "<esc><esc><enter><wait>",
  "/install/vmlinuz noapic ",
  "preseed/url=http://{{ .HTTPIP }}:{{ .HTTPPort }}/preseed.cfg ",
  "debian-installer=en_US auto locale=en_US kbd-chooser/method=us ",
  "hostname={{ .Name }} ",
  "fb=false debconf/frontend=noninteractive ",
  "keyboard-configuration/modelcode=SKIP keyboard-configuration/layout=USA ",
  "keyboard-configuration/variant=USA console-setup/ask_detect=false ",
  "initrd=/install/initrd.gz -- <enter>"
]

For more examples of various boot commands, see the sample projects from our community templates page.