VMware

This datasource is for use with systems running on a VMware platform such as vSphere and currently supports the following data transports:

The configuration method is dependent upon the transport.

Guest OS customization

The following configuration can be set for this datasource in cloud-init configuration (in /etc/cloud/cloud.cfg or /etc/cloud/cloud.cfg.d/).

System configuration

  • disable_vmware_customization: true (disable) or false (enable) the VMware traditional Linux guest customization. Traditional Linux guest customization is customizing a Linux virtual machine with a traditional Linux customization specification. Setting this configuration to false is required to make sure this datasource is found in ds-identify when using Guest OS customization transport. VMware Tools only checks this configuration in /etc/cloud/cloud.cfg.

    Default: true

Datasource configuration

  • allow_raw_data: true (enable) or false (disable) the VMware customization using cloud-init metadata and user data directly. Since vSphere 7.0 Update 3 version, users can create a Linux customization specification with minimal cloud-init metadata and user data, and apply this specification to a virtual machine. This datasource will parse the metadata and user data and configure the virtual machine with them. See Guest customization using cloud-init for more information.

    Default: true

  • vmware_cust_file_max_wait: The maximum amount of clock time (in seconds) that should be spent waiting for VMware customization files.

    Default: 15

Configuration examples

  1. Enable VMware customization and set the maximum waiting time for the VMware customization file to 10 seconds:

    Set disable_vmware_customization in the /etc/cloud/cloud.cfg

    disable_vmware_customization: false
    

    Create a /etc/cloud/cloud.cfg.d/99-vmware-guest-customization.cfg with the following content

    datasource:
      VMware:
        vmware_cust_file_max_wait: 10
    
  2. Enable VMware customization but only try to apply a traditional Linux Guest Customization configuration, and set the maximum waiting time for the VMware customization file to 10 seconds:

    Set disable_vmware_customization in the /etc/cloud/cloud.cfg

    disable_vmware_customization: false
    

    Create a /etc/cloud/cloud.cfg.d/99-vmware-guest-customization.cfg with the following content

    datasource:
      VMware:
        allow_raw_data: false
        vmware_cust_file_max_wait: 10
    

VMware Tools configuration

VMware Tools is required for this datasource’s configuration settings, as well as vCloud and vSphere admin configuration. Users can change the VMware Tools configuration options with the following command:

vmware-toolbox-cmd config set <section> <key> <value>

The following VMware Tools configuration option affects this datasource’s behaviour when applying customization configuration with custom scripts:

  • [deploypkg] enable-custom-scripts: If this option is absent in VMware Tools configuration, the custom script is disabled by default for security reasons. Some VMware products could change this default behaviour (for example: enabled by default) via customization of the specification settings.

    VMware admins can refer to customization configuration and set the customization specification settings.

For more information, see VMware vSphere Product Documentation and specific VMware Tools configuration options.

GuestInfo keys

One method of providing meta, user, and vendor data is by setting the following key/value pairs on a VM’s extraConfig property:

Property

Description

guestinfo.metadata

A YAML or JSON document containing the cloud-init metadata.

guestinfo.metadata.encoding

The encoding type for guestinfo.metadata.

guestinfo.userdata

A YAML document containing the cloud-init user data.

guestinfo.userdata.encoding

The encoding type for guestinfo.userdata.

guestinfo.vendordata

A YAML document containing the cloud-init vendor data.

guestinfo.vendordata.encoding

The encoding type for guestinfo.vendordata.

All guestinfo.*.encoding values may be set to base64 or gzip+base64.

Features

This section reviews several features available in this datasource.

Graceful rpctool fallback

The datasource initially attempts to use the program vmware-rpctool if it is available. However, if the program returns a non-zero exit code, then the datasource falls back to using the program vmtoolsd with the --cmd argument.

On some older versions of ESXi and open-vm-tools, the vmware-rpctool program is much more performant than vmtoolsd. While this gap was closed, it is not reasonable to expect the guest where cloud-init is running to know whether the underlying hypervisor has the patch.

Additionally, vSphere VMs may have the following present in their VMX file:

guest_rpc.rpci.auth.cmd.info-set = "TRUE"
guest_rpc.rpci.auth.cmd.info-get = "TRUE"

The above configuration causes the vmware-rpctool command to return a non-zero exit code with the error message Permission denied. If this should occur, the datasource falls back to using vmtoolsd.

Instance data and lazy networks

One of the hallmarks of cloud-init is its use of instance-data and JINJA queries – the ability to write queries in user and vendor data that reference runtime information present in /run/cloud-init/instance-data.json. This works well when the metadata provides all of the information up front, such as the network configuration. For systems that rely on DHCP, however, this information may not be available when the metadata is persisted to disk.

This datasource ensures that even if the instance is using DHCP to configure networking, the same details about the configured network are available in /run/cloud-init/instance-data.json as if static networking was used. This information collected at runtime is easy to demonstrate by executing the datasource on the command line. From the root of this repository, run the following command:

PYTHONPATH="$(pwd)" python3 cloudinit/sources/DataSourceVMware.py

The above command will result in output similar to the below JSON:

{
    "hostname": "akutz.localhost",
    "local-hostname": "akutz.localhost",
    "local-ipv4": "192.168.0.188",
    "local_hostname": "akutz.localhost",
    "network": {
        "config": {
            "dhcp": true
        },
        "interfaces": {
            "by-ipv4": {
                "172.0.0.2": {
                    "netmask": "255.255.255.255",
                    "peer": "172.0.0.2"
                },
                "192.168.0.188": {
                    "broadcast": "192.168.0.255",
                    "mac": "64:4b:f0:18:9a:21",
                    "netmask": "255.255.255.0"
                }
            },
            "by-ipv6": {
                "fd8e:d25e:c5b6:1:1f5:b2fd:8973:22f2": {
                    "flags": 208,
                    "mac": "64:4b:f0:18:9a:21",
                    "netmask": "ffff:ffff:ffff:ffff::/64"
                }
            },
            "by-mac": {
                "64:4b:f0:18:9a:21": {
                    "ipv4": [
                        {
                            "addr": "192.168.0.188",
                            "broadcast": "192.168.0.255",
                            "netmask": "255.255.255.0"
                        }
                    ],
                    "ipv6": [
                        {
                            "addr": "fd8e:d25e:c5b6:1:1f5:b2fd:8973:22f2",
                            "flags": 208,
                            "netmask": "ffff:ffff:ffff:ffff::/64"
                        }
                    ]
                },
                "ac:de:48:00:11:22": {
                    "ipv6": []
                }
            }
        }
    },
    "wait-on-network": {
        "ipv4": true,
        "ipv6": "false"
    }
}

Redacting sensitive information (GuestInfo keys transport only)

Sometimes the cloud-init user data might contain sensitive information, and it may be desirable to have the guestinfo.userdata key (or other guestinfo keys) redacted as soon as its data is read by the datasource. This is possible by adding the following to the metadata:

redact: # formerly named cleanup-guestinfo, which will also work
- userdata
- vendordata

When the above snippet is added to the metadata, the datasource will iterate over the elements in the redact array and clear each of the keys. For example, when the guestinfo transport is used, the above snippet will cause the following commands to be executed:

vmware-rpctool "info-set guestinfo.userdata ---"
vmware-rpctool "info-set guestinfo.userdata.encoding  "
vmware-rpctool "info-set guestinfo.vendordata ---"
vmware-rpctool "info-set guestinfo.vendordata.encoding  "

Please note that keys are set to the valid YAML string --- as it is not possible remove an existing key from the guestinfo key-space. A key’s analogous encoding property will be set to a single white-space character, causing the datasource to treat the actual key value as plain-text, thereby loading it as an empty YAML doc (hence the aforementioned ---).

Reading the local IP addresses

This datasource automatically discovers the local IPv4 and IPv6 addresses for a guest operating system based on the default routes. However, when inspecting a VM externally, it’s not possible to know what the default IP address is for the guest OS. That’s why this datasource sets the discovered, local IPv4 and IPv6 addresses back in the guestinfo namespace as the following keys:

  • guestinfo.local-ipv4

  • guestinfo.local-ipv6

It is possible that a host may not have any default, local IP addresses. It’s also possible the reported, local addresses are link-local addresses. But these two keys may be used to discover what this datasource determined were the local IPv4 and IPv6 addresses for a host.

Waiting on the network

Sometimes cloud-init may bring up the network, but it will not finish coming online before the datasource’s setup function is called, resulting in a /var/run/cloud-init/instance-data.json file that does not have the correct network information. It is possible to instruct the datasource to wait until an IPv4 or IPv6 address is available before writing the instance data with the following metadata properties:

wait-on-network:
  ipv4: true
  ipv6: true

If either of the above values are true, then the datasource will sleep for a second, check the network status, and repeat until one or both addresses from the specified families are available.

Walkthrough of GuestInfo keys transport

The following series of steps is a demonstration of how to configure a VM with this datasource using the GuestInfo keys transport:

  1. Create the metadata file for the VM. Save the following YAML to a file named metadata.yaml:

    instance-id: cloud-vm
    local-hostname: cloud-vm
    network:
      version: 2
      ethernets:
        nics:
          match:
            name: ens*
          dhcp4: yes
    
  2. Create the userdata file userdata.yaml:

    #cloud-config
    
    users:
    - default
    - name: akutz
      primary_group: akutz
      sudo: ALL=(ALL) NOPASSWD:ALL
      groups: sudo, wheel
      lock_passwd: true
      ssh_authorized_keys:
      - ssh-rsa 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 [email protected]
    
  3. Please note this step requires that the VM be powered off. All of the commands below use the VMware CLI tool, govc.

    Go ahead and assign the path to the VM to the environment variable VM:

    export VM="/inventory/path/to/the/vm"
    
  4. Power off the VM:


    ⚠️ First Boot Mode

    To ensure the next power-on operation results in a first-boot scenario for cloud-init, it may be necessary to run the following command just before powering off the VM:

    cloud-init clean --logs --machine-id
    

    Otherwise cloud-init may not run in first-boot mode. For more information on how the boot mode is determined, please see the first boot documentation.


    govc vm.power -off "${VM}"
    
  5. Export the environment variables that contain the cloud-init metadata and user data:

    export METADATA=$(gzip -c9 <metadata.yaml | { base64 -w0 2>/dev/null || base64; }) \
         USERDATA=$(gzip -c9 <userdata.yaml | { base64 -w0 2>/dev/null || base64; })
    
  6. Assign the metadata and user data to the VM:

    govc vm.change -vm "${VM}" \
    -e guestinfo.metadata="${METADATA}" \
    -e guestinfo.metadata.encoding="gzip+base64" \
    -e guestinfo.userdata="${USERDATA}" \
    -e guestinfo.userdata.encoding="gzip+base64"
    

    Note

    Please note the above commands include specifying the encoding for the properties. This is important as it informs the datasource how to decode the data for cloud-init. Valid values for metadata.encoding and userdata.encoding include:

    • base64

    • gzip+base64

  7. Power on the VM:

    govc vm.power -on "${VM}"
    

If all went according to plan, the CentOS box is:

  • Locked down, allowing SSH access only for the user in the user data.

  • Configured for a dynamic IP address via DHCP.

  • Has a hostname of cloud-vm.

Examples of common configurations

Setting the hostname

The hostname is set by way of the metadata key local-hostname.

Setting the instance ID

The instance ID may be set by way of the metadata key instance-id. However, if this value is absent then the instance ID is read from the file /sys/class/dmi/id/product_uuid.

Providing public SSH keys

The public SSH keys may be set by way of the metadata key public-keys-data. Each newline-terminated string will be interpreted as a separate SSH public key, which will be placed in distro’s default user’s ~/.ssh/authorized_keys. If the value is empty or absent, then nothing will be written to ~/.ssh/authorized_keys.

Configuring the network

The network is configured by setting the metadata key network with a value consistent with Network Config Version 1 or Version 2, depending on the Linux distro’s version of cloud-init.

The metadata key network.encoding may be used to indicate the format of the metadata key network. Valid encodings are base64 and gzip+base64.