Datasource for VMware (#953)

This patch finally introduces the Cloud-Init Datasource for VMware
GuestInfo as a part of cloud-init proper. This datasource has existed
since 2018, and rapidly became the de facto datasource for developers
working with Packer, Terraform, for projects like kube-image-builder,
and the de jure datasource for Photon OS.

The major change to the datasource from its previous incarnation is
the name. Now named DatasourceVMware, this new version of the
datasource will allow multiple transport types in addition to
GuestInfo keys.

This datasource includes several unique features developed to address
real-world situations:

  * Support for reading any key (metadata, userdata, vendordata) both
    from the guestinfo table when running on a VM in vSphere as well as
    from an environment variable when running inside of a container,
    useful for rapid dev/test.

  * Allows booting with DHCP while still providing full participation
    in Cloud-Init instance data and Jinja queries. The netifaces library
    provides the ability to inspect the network after it is online,
    and the runtime network configuration is then merged into the
    existing metadata and persisted to disk.

  * Advertises the local_ipv4 and local_ipv6 addresses via guestinfo
    as well. This is useful as Guest Tools is not always able to
    identify what would be considered the local address.

The primary author and current steward of this datasource spoke at
Cloud-Init Con 2020 where there was interest in contributing this datasource
to the Cloud-Init codebase.

The datasource currently lives in its own GitHub repository at
https://github.com/vmware/cloud-init-vmware-guestinfo. Once the datasource
is merged into Cloud-Init, the old repository will be deprecated.

3 files changed, 361 insertions, 0 deletions

diff --git a/doc/rtd/topics/availability.rst b/doc/rtd/topics/availability.rst
index e0644534..71827177 100644
--- a/doc/rtd/topics/availability.rst
+++ b/doc/rtd/topics/availability.rst
@@ -67,5 +67,6 @@ Additionally, cloud-init is supported on these private clouds:
 - LXD
 - KVM
 - Metal-as-a-Service (MAAS)
+- VMware
 
 .. vi: textwidth=79
diff --git a/doc/rtd/topics/datasources.rst b/doc/rtd/topics/datasources.rst
index 497b1467..f5aee1c2 100644
--- a/doc/rtd/topics/datasources.rst
+++ b/doc/rtd/topics/datasources.rst
@@ -50,6 +50,7 @@ The following is a list of documents for each supported datasource:
    datasources/upcloud.rst
    datasources/zstack.rst
    datasources/vultr.rst
+   datasources/vmware.rst
 
 Creation
 ========
diff --git a/doc/rtd/topics/datasources/vmware.rst b/doc/rtd/topics/datasources/vmware.rst
new file mode 100644
index 00000000..996eb61f
--- /dev/null
+++ b/doc/rtd/topics/datasources/vmware.rst
@@ -0,0 +1,359 @@
+.. _datasource_vmware:
+
+VMware
+======
+
+This datasource is for use with systems running on a VMware platform such as
+vSphere and currently supports the following data transports:
+
+
+* `GuestInfo <https://github.com/vmware/govmomi/blob/master/govc/USAGE.md#vmchange>`_ keys
+
+Configuration
+-------------
+
+The configuration method is dependent upon the transport:
+
+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 <https://vdc-repo.vmware.com/vmwb-repository/dcr-public/723e7f8b-4f21-448b-a830-5f22fd931b01/5a8257bd-7f41-4423-9a73-03307535bd42/doc/vim.vm.ConfigInfo.html>`_ :
+
+.. list-table::
+   :header-rows: 1
+
+   * - 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, regardless
+of how the meta, user, and vendor data was discovered.
+
+Instance data and lazy networks
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+One of the hallmarks of cloud-init is `its use of instance-data and JINJA
+queries <../instancedata.html#using-instance-data>`_
+-- 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:
+
+.. code-block:: bash
+
+   PYTHONPATH="$(pwd)" python3 cloudinit/sources/DataSourceVMware.py
+
+The above command will result in output similar to the below JSON:
+
+.. code-block:: 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
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Sometimes the cloud-init userdata 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:
+
+.. code-block:: yaml
+
+   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:
+
+.. code-block:: shell
+
+   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 an
+``/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:
+
+.. code-block:: yaml
+
+   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
+-----------
+
+The following series of steps is a demonstration on how to configure a VM with
+this datasource:
+
+
+#. Create the metadata file for the VM. Save the following YAML to a file named
+   ``metadata.yaml``\ :
+
+   .. code-block:: yaml
+
+       instance-id: cloud-vm
+       local-hostname: cloud-vm
+       network:
+         version: 2
+         ethernets:
+           nics:
+             match:
+               name: ens*
+             dhcp4: yes
+
+#. Create the userdata file ``userdata.yaml``\ :
+
+   .. code-block:: yaml
+
+       #cloud-config
+
+       users:
+       - default
+       - name: akutz
+           primary_group: akutz
+           sudo: ALL=(ALL) NOPASSWD:ALL
+           groups: sudo, wheel
+           ssh_import_id: None
+           lock_passwd: true
+           ssh_authorized_keys:
+           - ssh-rsa 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 sakutz@gmail.com
+
+#. Please note this step requires that the VM be powered off. All of the
+   commands below use the VMware CLI tool, `govc <https://github.com/vmware/govmomi/blob/master/govc>`_.
+
+   Go ahead and assign the path to the VM to the environment variable ``VM``\ :
+
+   .. code-block:: shell
+
+      export VM="/inventory/path/to/the/vm"
+
+#. Power off the VM:
+
+   .. raw:: html
+
+      <hr />
+
+      &#x26a0;&#xfe0f; <strong>First Boot Mode</strong>
+
+   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:
+
+   .. code-block:: bash
+
+      cloud-init clean
+
+   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 <../boot.html#first-boot-determination>`_.
+
+   .. raw:: html
+
+      <hr />
+
+   .. code-block:: shell
+
+      govc vm.power -off "${VM}"
+
+#.
+   Export the environment variables that contain the cloud-init metadata and
+   userdata:
+
+   .. code-block:: shell
+
+      export METADATA=$(gzip -c9 <metadata.yaml | { base64 -w0 2>/dev/null || base64; }) \
+           USERDATA=$(gzip -c9 <userdata.yaml | { base64 -w0 2>/dev/null || base64; })
+
+#.
+   Assign the metadata and userdata to the VM:
+
+   .. code-block:: shell
+
+       govc vm.change -vm "${VM}" \
+       -e guestinfo.metadata="${METADATA}" \
+       -e guestinfo.metadata.encoding="gzip+base64" \
+       -e guestinfo.userdata="${USERDATA}" \
+       -e guestinfo.userdata.encoding="gzip+base64"
+
+   Please note the above commands include specifying the encoding for the
+   properties. This is important as it informs the datasource how to decode
+   the data for cloud-init. Valid values for ``metadata.encoding`` and
+   ``userdata.encoding`` include:
+
+
+   * ``base64``
+   * ``gzip+base64``
+
+#.
+   Power on the VM:
+
+   .. code-block:: shell
+
+       govc vm.power -vm "${VM}" -on
+
+If all went according to plan, the CentOS box is:
+
+* Locked down, allowing SSH access only for the user in the userdata
+* Configured for a dynamic IP address via DHCP
+* Has a hostname of ``cloud-vm``
+
+Examples
+--------
+
+This section reviews 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 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 Versions
+`1 <../network-config-format-v1.html>`_ or
+`2 <../network-config-format-v2.html>`_\ , 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``.