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The VirtualBox plugin creates VirtualBox virtual machines and export them to an OVA or OVF format.

  • Official

Updated last month

VirtualBox OVF/OVA

Type: virtualbox-ovf Artifact BuilderId: mitchellh.virtualbox

This VirtualBox Packer builder is able to create VirtualBox virtual machines and export them in the OVF format, starting from an existing OVF/OVA (exported virtual machine image).

When exporting from VirtualBox make sure to choose OVF Version 2, since Version 1 is not compatible and will generate errors like this:

==> virtualbox-ovf: Progress state: VBOX_E_FILE_ERROR
==> virtualbox-ovf: VBoxManage: error: Appliance read failed
==> virtualbox-ovf: VBoxManage: error: Error reading "source.ova": element "Section" has no "type" attribute, line 21
==> virtualbox-ovf: VBoxManage: error: Details: code VBOX_E_FILE_ERROR (0x80bb0004), component Appliance, interface IAppliance
==> virtualbox-ovf: VBoxManage: error: Context: "int handleImportAppliance(HandlerArg*)" at line 304 of file VBoxManageAppliance.cpp

The builder builds a virtual machine by importing an existing OVF or OVA file. It then boots this image, runs provisioners on this new VM, and exports that VM to create the image. The imported machine is deleted prior to finishing the build.

Basic Example

Here is a basic example. This example is functional if you have an OVF matching the settings here.

JSON

{
  "type": "virtualbox-ovf",
  "source_path": "source.ovf",
  "ssh_username": "packer",
  "ssh_password": "packer",
  "shutdown_command": "echo 'packer' | sudo -S shutdown -P now"
}

HCL2

source "virtualbox-ovf" "basic-example" {
  source_path = "source.ovf"
  ssh_username = "packer"
  ssh_password = "packer"
  shutdown_command = "echo 'packer' | sudo -S shutdown -P now"
}

build {
  sources = ["sources.virtualbox-ovf.basic-example"]
}

It is important to add a shutdown_command. By default Packer halts the virtual machine and the file system may not be sync'd. Thus, changes made in a provisioner might not be saved.

Configuration Reference

There are many configuration options available for the builder. In addition to the items listed here, you will want to look at the general configuration references for ISO, HTTP, Floppy, Export, Boot, Shutdown, Run, Communicator configuration references, which are necessary for this build to succeed and can be found further down the page.

Required:

  • checksum (string) - The checksum for the source_path file. The type of the checksum is specified within the checksum field as a prefix, ex: "md5:{$checksum}". The type of the checksum can also be omitted and Packer will try to infer it based on string length. Valid values are "none", "{$checksum}", "md5:{$checksum}", "sha1:{$checksum}", "sha256:{$checksum}", "sha512:{$checksum}" or "file:{$path}". Here is a list of valid checksum values:

    • md5:090992ba9fd140077b0661cb75f7ce13
    • 090992ba9fd140077b0661cb75f7ce13
    • sha1:ebfb681885ddf1234c18094a45bbeafd91467911
    • ebfb681885ddf1234c18094a45bbeafd91467911
    • sha256:ed363350696a726b7932db864dda019bd2017365c9e299627830f06954643f93
    • ed363350696a726b7932db864dda019bd2017365c9e299627830f06954643f93
    • file:http://releases.ubuntu.com/20.04/SHA256SUMS
    • file:file://./local/path/file.sum
    • file:./local/path/file.sum
    • none Although the checksum will not be verified when it is set to "none", this is not recommended since these files can be very large and corruption does happen from time to time.

  • source_path (string) - The filepath or URL to an OVF or OVA file that acts as the source of this build.

Optional:

  • import_flags ([]string) - Additional flags to pass to VBoxManage import. This can be used to add additional command-line flags such as --eula-accept to accept a EULA in the OVF.

  • import_opts (string) - Additional options to pass to the VBoxManage import. This can be useful for passing keepallmacs or keepnatmacs options for existing ovf images.

  • target_path (string) - The path where the OVA should be saved after download. By default, it will go in the packer cache, with a hash of the original filename as its name.

  • vm_name (string) - This is the name of the OVF file for the new virtual machine, without the file extension. By default this is packer-BUILDNAME, where "BUILDNAME" is the name of the build.

  • keep_registered (bool) - Set this to true if you would like to keep the VM registered with virtualbox. Defaults to false.

  • skip_export (bool) - Defaults to false. When enabled, Packer will not export the VM. Useful if the build output is not the resultant image, but created inside the VM.

  • virtualbox_version_file (*string) - The path within the virtual machine to upload a file that contains the VirtualBox version that was used to create the machine. This information can be useful for provisioning. By default this is .vbox_version, which will generally be upload it into the home directory. Set to an empty string to skip uploading this file, which can be useful when using the none communicator.

  • guest_additions_mode (string) - The method by which guest additions are made available to the guest for installation. Valid options are upload, attach, or disable. If the mode is attach the guest additions ISO will be attached as a CD device to the virtual machine. If the mode is upload the guest additions ISO will be uploaded to the path specified by guest_additions_path. The default value is upload. If disable is used, guest additions won't be downloaded, either.

  • guest_additions_interface (string) - The interface type to use to mount guest additions when guest_additions_mode is set to attach. Will default to the value set in iso_interface, if iso_interface is set. Will default to "ide", if iso_interface is not set. Options are "ide" and "sata".

  • guest_additions_path (string) - The path on the guest virtual machine where the VirtualBox guest additions ISO will be uploaded. By default this is VBoxGuestAdditions.iso which should upload into the login directory of the user. This is a configuration template where the Version variable is replaced with the VirtualBox version.

  • guest_additions_sha256 (string) - The SHA256 checksum of the guest additions ISO that will be uploaded to the guest VM. By default the checksums will be downloaded from the VirtualBox website, so this only needs to be set if you want to be explicit about the checksum.

  • guest_additions_url (string) - The URL of the guest additions ISO to upload. This can also be a file URL if the ISO is at a local path. By default, the VirtualBox builder will attempt to find the guest additions ISO on the local file system. If it is not available locally, the builder will download the proper guest additions ISO from the internet.

VBoxManage configuration

  • vboxmanage ([][]string) - Custom VBoxManage commands to execute in order to further customize the virtual machine being created. The example shown below sets the memory and number of CPUs within the virtual machine:

    In JSON:

    "vboxmanage": [
   ["modifyvm", "{{.Name}}", "--memory", "1024"],
   ["modifyvm", "{{.Name}}", "--cpus", "2"]
]

    In HCL2:

    vboxmanage = [
   ["modifyvm", "{{.Name}}", "--memory", "1024"],
   ["modifyvm", "{{.Name}}", "--cpus", "2"],
]

    The value of vboxmanage is an array of commands to execute. These commands are executed in the order defined. So in the above example, the memory will be set followed by the CPUs. Each command itself is an array of strings, where each string is an argument to VBoxManage. Each argument is treated as a configuration template. The only available variable is Name which is replaced with the unique name of the VM, which is required for many VBoxManage calls.

  • vboxmanage_post ([][]string) - Identical to vboxmanage, except that it is run after the virtual machine is shutdown, and before the virtual machine is exported.

Http directory configuration

Packer will create an http server serving http_directory when it is set, a random free port will be selected and the architecture of the directory referenced will be available in your builder.

Example usage from a builder:

wget http://{{ .HTTPIP }}:{{ .HTTPPort }}/foo/bar/preseed.cfg

Optional:

  • http_directory (string) - Path to a directory to serve using an HTTP server. The files in this directory will be available over HTTP that will be requestable from the virtual machine. This is useful for hosting kickstart files and so on. By default this is an empty string, which means no HTTP server will be started. The address and port of the HTTP server will be available as variables in boot_command. This is covered in more detail below.

  • http_content (map[string]string) - Key/Values to serve using an HTTP server. http_content works like and conflicts with http_directory. The keys represent the paths and the values contents, the keys must start with a slash, ex: /path/to/file. http_content is useful for hosting kickstart files and so on. By default this is empty, which means no HTTP server will be started. The address and port of the HTTP server will be available as variables in boot_command. This is covered in more detail below. Example:

      http_content = {
    "/a/b"     = file("http/b")
    "/foo/bar" = templatefile("${path.root}/preseed.cfg", { packages = ["nginx"] })
  }

  • http_port_min (int) - These are the minimum and maximum port to use for the HTTP server started to serve the http_directory. Because Packer often runs in parallel, Packer will choose a randomly available port in this range to run the HTTP server. If you want to force the HTTP server to be on one port, make this minimum and maximum port the same. By default the values are 8000 and 9000, respectively.

  • http_port_max (int) - HTTP Port Max

  • http_bind_address (string) - This is the bind address for the HTTP server. Defaults to 0.0.0.0 so that it will work with any network interface.

Floppy configuration

A floppy can be made available for your build. This is most useful for unattended Windows installs, which look for an Autounattend.xml file on removable media. By default, no floppy will be attached. All files listed in this setting get placed into the root directory of the floppy and the floppy is attached as the first floppy device. The summary size of the listed files must not exceed 1.44 MB. The supported ways to move large files into the OS are using http_directory or the file provisioner.

Optional:

  • floppy_files ([]string) - A list of files to place onto a floppy disk that is attached when the VM is booted. Currently, no support exists for creating sub-directories on the floppy. Wildcard characters (\*, ?, and []) are allowed. Directory names are also allowed, which will add all the files found in the directory to the floppy.

  • floppy_dirs ([]string) - A list of directories to place onto the floppy disk recursively. This is similar to the floppy_files option except that the directory structure is preserved. This is useful for when your floppy disk includes drivers or if you just want to organize it's contents as a hierarchy. Wildcard characters (\*, ?, and []) are allowed. The maximum summary size of all files in the listed directories are the same as in floppy_files.

  • floppy_content (map[string]string) - Key/Values to add to the floppy disk. The keys represent the paths, and the values contents. It can be used alongside floppy_files or floppy_dirs, which is useful to add large files without loading them into memory. If any paths are specified by both, the contents in floppy_content will take precedence.

    Usage example (HCL):

    floppy_files = ["vendor-data"]
floppy_content = {
  "meta-data" = jsonencode(local.instance_data)
  "user-data" = templatefile("user-data", { packages = ["nginx"] })
}
floppy_label = "cidata"

  • floppy_label (string) - Floppy Label

CD configuration

An iso (CD) containing custom files can be made available for your build.

By default, no extra CD will be attached. All files listed in this setting get placed into the root directory of the CD and the CD is attached as the second CD device.

This config exists to work around modern operating systems that have no way to mount floppy disks, which was our previous go-to for adding files at boot time.

Optional:

  • cd_files ([]string) - A list of files to place onto a CD that is attached when the VM is booted. This can include either files or directories; any directories will be copied onto the CD recursively, preserving directory structure hierarchy. Symlinks will have the link's target copied into the directory tree on the CD where the symlink was. File globbing is allowed.

    Usage example (JSON):

    "cd_files": ["./somedirectory/meta-data", "./somedirectory/user-data"],
"cd_label": "cidata",

    Usage example (HCL):

    cd_files = ["./somedirectory/meta-data", "./somedirectory/user-data"]
cd_label = "cidata"

    The above will create a CD with two files, user-data and meta-data in the CD root. This specific example is how you would create a CD that can be used for an Ubuntu 20.04 autoinstall.

    Since globbing is also supported,

    cd_files = ["./somedirectory/*"]
cd_label = "cidata"

    Would also be an acceptable way to define the above cd. The difference between providing the directory with or without the glob is whether the directory itself or its contents will be at the CD root.

    Use of this option assumes that you have a command line tool installed that can handle the iso creation. Packer will use one of the following tools:

    • xorriso
    • mkisofs
    • hdiutil (normally found in macOS)
    • oscdimg (normally found in Windows as part of the Windows ADK)

  • cd_content (map[string]string) - Key/Values to add to the CD. The keys represent the paths, and the values contents. It can be used alongside cd_files, which is useful to add large files without loading them into memory. If any paths are specified by both, the contents in cd_content will take precedence.

    Usage example (HCL):

    cd_files = ["vendor-data"]
cd_content = {
  "meta-data" = jsonencode(local.instance_data)
  "user-data" = templatefile("user-data", { packages = ["nginx"] })
}
cd_label = "cidata"

  • cd_label (string) - CD Label

Export configuration

Optional:

  • format (string) - Either ovf or ova, this specifies the output format of the exported virtual machine. This defaults to ovf.

  • export_opts ([]string) - Additional options to pass to the VBoxManage export. This can be useful for passing product information to include in the resulting appliance file. Packer JSON configuration file example:

    In JSON:

    {
  "type": "virtualbox-iso",
  "export_opts":
  [
    "--manifest",
    "--vsys", "0",
    "--description", "{{user `vm_description`}}",
    "--version", "{{user `vm_version`}}"
  ],
  "format": "ova",
}

    In HCL2:

        source "virtualbox-iso" "basic-example" {
        export_opts = [
              "--manifest",
              "--vsys", "0",
              "--description", "${var.vm_description}",
              "--version", "${var.vm_version}"
        ]
        format = "ova"
 }

    A VirtualBox VM description may contain arbitrary strings; the GUI interprets HTML formatting. However, the JSON format does not allow arbitrary newlines within a value. Add a multi-line description by preparing the string in the shell before the packer call like this (shell > continuation character snipped for easier copy & paste):

    vm_description='some
multiline
description'

vm_version='0.2.0'

packer build \
    -var "vm_description=${vm_description}" \
    -var "vm_version=${vm_version}"         \
    "packer_conf.json"

Output configuration

Optional:

  • output_directory (string) - This is the path to the directory where the resulting virtual machine will be created. This may be relative or absolute. If relative, the path is relative to the working directory when packer is executed. This directory must not exist or be empty prior to running the builder. By default this is output-BUILDNAME where "BUILDNAME" is the name of the build.

  • output_filename (string) - This is the base name of the file (excluding the file extension) where the resulting virtual machine will be created. By default this is the vm_name.

Run configuration

Optional:

  • headless (bool) - Packer defaults to building VirtualBox virtual machines by launching a GUI that shows the console of the machine being built. When this value is set to true, the machine will start without a console.

  • vrdp_bind_address (string) - The IP address that should be binded to for VRDP. By default packer will use 127.0.0.1 for this. If you wish to bind to all interfaces use 0.0.0.0.

  • vrdp_port_min (int) - The minimum and maximum port to use for VRDP access to the virtual machine. Packer uses a randomly chosen port in this range that appears available. By default this is 5900 to 6000. The minimum and maximum ports are inclusive.

  • vrdp_port_max (int) - VRDP Port Max

Shutdown configuration

Optional:

  • shutdown_command (string) - The command to use to gracefully shut down the machine once all the provisioning is done. By default this is an empty string, which tells Packer to just forcefully shut down the machine unless a shutdown command takes place inside script so this may safely be omitted. If one or more scripts require a reboot it is suggested to leave this blank since reboots may fail and specify the final shutdown command in your last script.

  • shutdown_timeout (duration string | ex: "1h5m2s") - The amount of time to wait after executing the shutdown_command for the virtual machine to actually shut down. If it doesn't shut down in this time, it is an error. By default, the timeout is 5m or five minutes.

  • post_shutdown_delay (duration string | ex: "1h5m2s") - The amount of time to wait after shutting down the virtual machine. If you get the error Error removing floppy controller, you might need to set this to 5m or so. By default, the delay is 0s or disabled.

  • disable_shutdown (bool) - Packer normally halts the virtual machine after all provisioners have run when no shutdown_command is defined. If this is set to true, Packer will not halt the virtual machine but will assume that you will send the stop signal yourself through the preseed.cfg or your final provisioner. Packer will wait for a default of 5 minutes until the virtual machine is shutdown. The timeout can be changed using shutdown_timeout option.

  • acpi_shutdown (bool) - If it's set to true, it will shutdown the VM via power button. It could be a good option when keeping the machine state is necessary after shutting it down.

Communicator configuration

Optional common fields:

  • communicator (string) - Packer currently supports three kinds of communicators:

    • none - No communicator will be used. If this is set, most provisioners also can't be used.

    • ssh - An SSH connection will be established to the machine. This is usually the default.

    • winrm - A WinRM connection will be established.

    In addition to the above, some builders have custom communicators they can use. For example, the Docker builder has a "docker" communicator that uses docker exec and docker cp to execute scripts and copy files.

  • pause_before_connecting (duration string | ex: "1h5m2s") - We recommend that you enable SSH or WinRM as the very last step in your guest's bootstrap script, but sometimes you may have a race condition where you need Packer to wait before attempting to connect to your guest.

    If you end up in this situation, you can use the template option pause_before_connecting. By default, there is no pause. For example if you set pause_before_connecting to 10m Packer will check whether it can connect, as normal. But once a connection attempt is successful, it will disconnect and then wait 10 minutes before connecting to the guest and beginning provisioning.

  • host_port_min (int) - The minimum port to use for the Communicator port on the host machine which is forwarded to the SSH or WinRM port on the guest machine. By default this is 2222.

  • host_port_max (int) - The maximum port to use for the Communicator port on the host machine which is forwarded to the SSH or WinRM port on the guest machine. Because Packer often runs in parallel, Packer will choose a randomly available port in this range to use as the host port. By default this is 4444.

  • skip_nat_mapping (bool) - Defaults to false. When enabled, Packer does not setup forwarded port mapping for communicator (SSH or WinRM) requests and uses ssh_port or winrm_port on the host to communicate to the virtual machine.

Optional SSH fields:

  • ssh_host (string) - The address to SSH to. This usually is automatically configured by the builder.

  • ssh_port (int) - The port to connect to SSH. This defaults to 22.

  • ssh_username (string) - The username to connect to SSH with. Required if using SSH.

  • ssh_password (string) - A plaintext password to use to authenticate with SSH.

  • ssh_ciphers ([]string) - This overrides the value of ciphers supported by default by Golang. The default value is [ "aes128-gcm@openssh.com", "chacha20-poly1305@openssh.com", "aes128-ctr", "aes192-ctr", "aes256-ctr", ]

    Valid options for ciphers include: "aes128-ctr", "aes192-ctr", "aes256-ctr", "aes128-gcm@openssh.com", "chacha20-poly1305@openssh.com", "arcfour256", "arcfour128", "arcfour", "aes128-cbc", "3des-cbc",

  • ssh_clear_authorized_keys (bool) - If true, Packer will attempt to remove its temporary key from ~/.ssh/authorized_keys and /root/.ssh/authorized_keys. This is a mostly cosmetic option, since Packer will delete the temporary private key from the host system regardless of whether this is set to true (unless the user has set the -debug flag). Defaults to "false"; currently only works on guests with sed installed.

  • ssh_key_exchange_algorithms ([]string) - If set, Packer will override the value of key exchange (kex) algorithms supported by default by Golang. Acceptable values include: "curve25519-sha256@libssh.org", "ecdh-sha2-nistp256", "ecdh-sha2-nistp384", "ecdh-sha2-nistp521", "diffie-hellman-group14-sha1", and "diffie-hellman-group1-sha1".

  • ssh_certificate_file (string) - Path to user certificate used to authenticate with SSH. The ~ can be used in path and will be expanded to the home directory of current user.

  • ssh_pty (bool) - If true, a PTY will be requested for the SSH connection. This defaults to false.

  • ssh_timeout (duration string | ex: "1h5m2s") - The time to wait for SSH to become available. Packer uses this to determine when the machine has booted so this is usually quite long. Example value: 10m. This defaults to 5m, unless ssh_handshake_attempts is set.

  • ssh_disable_agent_forwarding (bool) - If true, SSH agent forwarding will be disabled. Defaults to false.

  • ssh_handshake_attempts (int) - The number of handshakes to attempt with SSH once it can connect. This defaults to 10, unless a ssh_timeout is set.

  • ssh_bastion_host (string) - A bastion host to use for the actual SSH connection.

  • ssh_bastion_port (int) - The port of the bastion host. Defaults to 22.

  • ssh_bastion_agent_auth (bool) - If true, the local SSH agent will be used to authenticate with the bastion host. Defaults to false.

  • ssh_bastion_username (string) - The username to connect to the bastion host.

  • ssh_bastion_password (string) - The password to use to authenticate with the bastion host.

  • ssh_bastion_interactive (bool) - If true, the keyboard-interactive used to authenticate with bastion host.

  • ssh_bastion_private_key_file (string) - Path to a PEM encoded private key file to use to authenticate with the bastion host. The ~ can be used in path and will be expanded to the home directory of current user.

  • ssh_bastion_certificate_file (string) - Path to user certificate used to authenticate with bastion host. The ~ can be used in path and will be expanded to the home directory of current user.

  • ssh_file_transfer_method (string) - scp or sftp - How to transfer files, Secure copy (default) or SSH File Transfer Protocol.

    NOTE: Guests using Windows with Win32-OpenSSH v9.1.0.0p1-Beta, scp (the default protocol for copying data) returns a a non-zero error code since the MOTW cannot be set, which cause any file transfer to fail. As a workaround you can override the transfer protocol with SFTP instead ssh_file_transfer_protocol = "sftp".

  • ssh_proxy_host (string) - A SOCKS proxy host to use for SSH connection

  • ssh_proxy_port (int) - A port of the SOCKS proxy. Defaults to 1080.

  • ssh_proxy_username (string) - The optional username to authenticate with the proxy server.

  • ssh_proxy_password (string) - The optional password to use to authenticate with the proxy server.

  • ssh_keep_alive_interval (duration string | ex: "1h5m2s") - How often to send "keep alive" messages to the server. Set to a negative value (-1s) to disable. Example value: 10s. Defaults to 5s.

  • ssh_read_write_timeout (duration string | ex: "1h5m2s") - The amount of time to wait for a remote command to end. This might be useful if, for example, packer hangs on a connection after a reboot. Example: 5m. Disabled by default.

  • ssh_remote_tunnels ([]string) -

  • ssh_local_tunnels ([]string) -

  • temporary_key_pair_type (string) - dsa | ecdsa | ed25519 | rsa ( the default )

    Specifies the type of key to create. The possible values are 'dsa', 'ecdsa', 'ed25519', or 'rsa'.

    NOTE: DSA is deprecated and no longer recognized as secure, please consider other alternatives like RSA or ED25519.

  • temporary_key_pair_bits (int) - Specifies the number of bits in the key to create. For RSA keys, the minimum size is 1024 bits and the default is 4096 bits. Generally, 3072 bits is considered sufficient. DSA keys must be exactly 1024 bits as specified by FIPS 186-2. For ECDSA keys, bits determines the key length by selecting from one of three elliptic curve sizes: 256, 384 or 521 bits. Attempting to use bit lengths other than these three values for ECDSA keys will fail. Ed25519 keys have a fixed length and bits will be ignored.

    NOTE: DSA is deprecated and no longer recognized as secure as specified by FIPS 186-5, please consider other alternatives like RSA or ED25519.

  • ssh_keypair_name (string) - If specified, this is the key that will be used for SSH with the machine. The key must match a key pair name loaded up into the remote. By default, this is blank, and Packer will generate a temporary keypair unless ssh_password is used. ssh_private_key_file or ssh_agent_auth must be specified when ssh_keypair_name is utilized.
  • ssh_private_key_file (string) - Path to a PEM encoded private key file to use to authenticate with SSH. The ~ can be used in path and will be expanded to the home directory of current user.
  • ssh_agent_auth (bool) - If true, the local SSH agent will be used to authenticate connections to the source instance. No temporary keypair will be created, and the values of ssh_password and ssh_private_key_file will be ignored. The environment variable SSH_AUTH_SOCK must be set for this option to work properly.

Optional WinRM fields:

  • winrm_username (string) - The username to use to connect to WinRM.

  • winrm_password (string) - The password to use to connect to WinRM.

  • winrm_host (string) - The address for WinRM to connect to.

    NOTE: If using an Amazon EBS builder, you can specify the interface WinRM connects to via ssh_interface

  • winrm_no_proxy (bool) - Setting this to true adds the remote host:port to the NO_PROXY environment variable. This has the effect of bypassing any configured proxies when connecting to the remote host. Default to false.

  • winrm_port (int) - The WinRM port to connect to. This defaults to 5985 for plain unencrypted connection and 5986 for SSL when winrm_use_ssl is set to true.

  • winrm_timeout (duration string | ex: "1h5m2s") - The amount of time to wait for WinRM to become available. This defaults to 30m since setting up a Windows machine generally takes a long time.

  • winrm_use_ssl (bool) - If true, use HTTPS for WinRM.

  • winrm_insecure (bool) - If true, do not check server certificate chain and host name.

  • winrm_use_ntlm (bool) - If true, NTLMv2 authentication (with session security) will be used for WinRM, rather than default (basic authentication), removing the requirement for basic authentication to be enabled within the target guest. Further reading for remote connection authentication can be found here.

Boot Configuration

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.

Please note that for the Virtuabox builder, the IP address of the HTTP server Packer launches for you to access files like the preseed file in the example above ({{ .HTTPIP }}) is hardcoded to 10.0.2.2. If you change the network of your VM you must guarantee that you can still access this HTTP server.

The boot command is sent to the VM through the VBoxManage utility in as few invocations as possible. We send each character in groups of 25, with a default delay of 100ms between groups. The delay alleviates issues with latency and CPU contention. If you notice missing keys, you can tune this delay by specifying "boot_keygroup_interval" in your Packer template, for example:

JSON

{
  "builders": [
    {
      "type": "virtualbox-ovf",
      "boot_keygroup_interval": "500ms"
      ...
    }
  ]
}

HCL2

source "virtualbox-ovf" "basic-example" {
  boot_keygroup_interval = "500ms"
  # ...
}

Optional:

  • boot_keygroup_interval (duration string | ex: "1h5m2s") - Time to wait after sending a group of key pressses. The value of this should be a duration. Examples are 5s and 1m30s which will cause Packer to wait five seconds and one minute 30 seconds, respectively. If this isn't specified, a sensible default value is picked depending on the builder type.

  • boot_wait (duration string | ex: "1h5m2s") - The time to wait after booting the initial virtual machine before typing the boot_command. The value of this should be a duration. Examples are 5s and 1m30s which will cause Packer to wait five seconds and one minute 30 seconds, respectively. If this isn't specified, the default is 10s or 10 seconds. To set boot_wait to 0s, use a negative number, such as "-1s"

  • boot_command ([]string) - This is an array of commands to type when the virtual machine is first booted. The goal of these commands should be to type just enough to initialize the operating system installer. Special keys can be typed as well, and are covered in the section below on the boot command. If this is not specified, it is assumed the installer will start itself.

SSH key pair automation

The VirtualBox builders can inject the current SSH key pair's public key into the template using the SSHPublicKey template engine. This is the SSH public key as a line in OpenSSH authorized_keys format.

When a private key is provided using ssh_private_key_file, the key's corresponding public key can be accessed using the above engine.

  • ssh_private_key_file (string) - Path to a PEM encoded private key file to use to authenticate with SSH. The ~ can be used in path and will be expanded to the home directory of current user.

If ssh_password and ssh_private_key_file are not specified, Packer will automatically generate en ephemeral key pair. The key pair's public key can be accessed using the template engine.

For example, the public key can be provided in the boot command as a URL encoded string by appending | urlquery to the variable:

In JSON:

"boot_command": [
  "<up><wait><tab> text ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/ks.cfg PACKER_USER={{ user `username` }} PACKER_AUTHORIZED_KEY={{ .SSHPublicKey | urlquery }}<enter>"
]

In HCL2:

boot_command = [
  "<up><wait><tab> text ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/ks.cfg PACKER_USER={{ user `username` }} PACKER_AUTHORIZED_KEY={{ .SSHPublicKey | urlquery }}<enter>"
]

A kickstart could then leverage those fields from the kernel command line by decoding the URL-encoded public key:

%post

# Newly created users need the file/folder framework for SSH key authentication.
umask 0077
mkdir /etc/skel/.ssh
touch /etc/skel/.ssh/authorized_keys

# Loop over the command line. Set interesting variables.
for x in $(cat /proc/cmdline)
do
  case $x in
    PACKER_USER=*)
      PACKER_USER="${x#*=}"
      ;;
    PACKER_AUTHORIZED_KEY=*)
      # URL decode $encoded into $PACKER_AUTHORIZED_KEY
      encoded=$(echo "${x#*=}" | tr '+' ' ')
      printf -v PACKER_AUTHORIZED_KEY '%b' "${encoded//%/\\x}"
      ;;
  esac
done

# Create/configure packer user, if any.
if [ -n "$PACKER_USER" ]
then
  useradd $PACKER_USER
  echo "%$PACKER_USER ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/$PACKER_USER
  [ -n "$PACKER_AUTHORIZED_KEY" ] && echo $PACKER_AUTHORIZED_KEY >> $(eval echo ~"$PACKER_USER")/.ssh/authorized_keys
fi

%end

Guest Additions

Packer will automatically download the proper guest additions for the version of VirtualBox that is running and upload those guest additions into the virtual machine so that provisioners can easily install them.

Packer downloads the guest additions from the official VirtualBox website, and verifies the file with the official checksums released by VirtualBox.

After the virtual machine is up and the operating system is installed, Packer uploads the guest additions into the virtual machine. The path where they are uploaded is controllable by guest_additions_path, and defaults to "VBoxGuestAdditions.iso". Without an absolute path, it is uploaded to the home directory of the SSH user.

VBoxManage Commands

In order to perform extra customization of the virtual machine, a template can define extra calls to VBoxManage to perform. VBoxManage is the command-line interface to VirtualBox where you can completely control VirtualBox. It can be used to do things such as set RAM, CPUs, etc.

  • vboxmanage ([][]string) - Custom VBoxManage commands to execute in order to further customize the virtual machine being created. The example shown below sets the memory and number of CPUs within the virtual machine:

    In JSON:

    "vboxmanage": [
   ["modifyvm", "{{.Name}}", "--memory", "1024"],
   ["modifyvm", "{{.Name}}", "--cpus", "2"]
]

    In HCL2:

    vboxmanage = [
   ["modifyvm", "{{.Name}}", "--memory", "1024"],
   ["modifyvm", "{{.Name}}", "--cpus", "2"],
]

    The value of vboxmanage is an array of commands to execute. These commands are executed in the order defined. So in the above example, the memory will be set followed by the CPUs. Each command itself is an array of strings, where each string is an argument to VBoxManage. Each argument is treated as a configuration template. The only available variable is Name which is replaced with the unique name of the VM, which is required for many VBoxManage calls.

  • vboxmanage_post ([][]string) - Identical to vboxmanage, except that it is run after the virtual machine is shutdown, and before the virtual machine is exported.