vmware: Fall back to vmtoolsd if vmware-rpctool errs (#4444)

This patch updates the ds-identify script and the
VMware datasource to fall back to using the
vmtoolsd program if vmware-rpctool errors.

Fixes GH-4436

cloudinit/sources/DataSourceOVF.py

@@ -8,6 +8,11 @@
 #
 # This file is part of cloud-init. See LICENSE file for license information.
 
+"""Cloud-Init DataSource for OVF
+
+This module provides a cloud-init datasource for OVF data.
+"""
+
 import base64
 import logging
 import os
@@ -20,7 +25,6 @@
 
 
 class DataSourceOVF(sources.DataSource):
-
     dsname = "OVF"
 
     def __init__(self, sys_cfg, distro, paths):
@@ -142,7 +146,7 @@ def read_ovf_environment(contents, read_network=False):
     cfg_props = ["password"]
     md_props = ["seedfrom", "local-hostname", "public-keys", "instance-id"]
     network_props = ["network-config"]
-    for (prop, val) in props.items():
+    for prop, val in props.items():
         if prop == "hostname":
             prop = "local-hostname"
         if prop in md_props:
@@ -220,10 +224,9 @@ def maybe_cdrom_device(devname):
 # Transport functions are called with no arguments and return
 # either None (indicating not present) or string content of an ovf-env.xml
 def transport_iso9660(require_iso=True):
-
     # Go through mounts to see if it was already mounted
     mounts = util.mounts()
-    for (dev, info) in mounts.items():
+    for dev, info in mounts.items():
         fstype = info["fstype"]
         if fstype != "iso9660" and require_iso:
             continue
@@ -258,22 +261,85 @@ def transport_iso9660(require_iso=True):
     return None
 
 
+def exec_vmware_rpctool(rpctool, arg):
+    cmd = [rpctool, arg]
+    (stdout, stderr) = subp.subp(cmd)
+    return (cmd, stdout, stderr)
+
+
+def exec_vmtoolsd(rpctool, arg):
+    cmd = [rpctool, "--cmd", arg]
+    (stdout, stderr) = subp.subp(cmd)
+    return (cmd, stdout, stderr)
+
+
 def transport_vmware_guestinfo():
-    rpctool = "vmware-rpctool"
-    not_found = None
-    if not subp.which(rpctool):
-        return not_found
-    cmd = [rpctool, "info-get guestinfo.ovfEnv"]
+    rpctool, rpctool_fn = None, None
+    vmtoolsd = subp.which("vmtoolsd")
+    vmware_rpctool = subp.which("vmware-rpctool")
+
+    # Default to using vmware-rpctool if it is available.
+    if vmware_rpctool:
+        rpctool, rpctool_fn = vmware_rpctool, exec_vmware_rpctool
+        LOG.debug("discovered vmware-rpctool: %s", vmware_rpctool)
+
+    if vmtoolsd:
+        # Default to using vmtoolsd if it is available and vmware-rpctool is
+        # not.
+        if not vmware_rpctool:
+            rpctool, rpctool_fn = vmtoolsd, exec_vmtoolsd
+        LOG.debug("discovered vmtoolsd: %s", vmtoolsd)
+
+    # If neither vmware-rpctool nor vmtoolsd are available, then nothing can
+    # be done.
+    if not rpctool:
+        LOG.debug("no rpctool discovered")
+        return None
+
+    def query_guestinfo(rpctool, rpctool_fn):
+        LOG.info("query guestinfo.ovfEnv with %s", rpctool)
+        try:
+            cmd, stdout, _ = rpctool_fn(rpctool, "info-get guestinfo.ovfEnv")
+            if stdout:
+                return stdout
+            LOG.debug("cmd %s exited 0 with empty stdout", cmd)
+            return None
+        except subp.ProcessExecutionError as error:
+            if error.exit_code != 1:
+                LOG.warning("%s exited with code %d", rpctool, error.exit_code)
+            raise error
+
     try:
-        out, _err = subp.subp(cmd)
-        if out:
-            return out
-        LOG.debug("cmd %s exited 0 with empty stdout: %s", cmd, out)
-    except subp.ProcessExecutionError as e:
-        if e.exit_code != 1:
-            LOG.warning("%s exited with code %d", rpctool, e.exit_code)
-            LOG.debug(e)
-    return not_found
+        # The first attempt to query guestinfo could occur via either
+        # vmware-rpctool *or* vmtoolsd.
+        return query_guestinfo(rpctool, rpctool_fn)
+    except subp.ProcessExecutionError as error:
+        # The second attempt to query guestinfo can only occur with
+        # vmtoolsd.
+
+        # If the first attempt at getting the data was with vmtoolsd, then
+        # no second attempt is made.
+        if vmtoolsd and rpctool == vmtoolsd:
+            # The fallback failed, log the error.
+            util.logexc(
+                LOG, "vmtoolsd failed to get guestinfo.ovfEnv: %s", error
+            )
+            return None
+
+        if not vmtoolsd:
+            LOG.info("vmtoolsd fallback option not present")
+            return None
+
+        try:
+            LOG.info("fallback to vmtoolsd")
+            return query_guestinfo(vmtoolsd, exec_vmtoolsd)
+        except subp.ProcessExecutionError as error:
+            # The fallback failed, log the error.
+            util.logexc(
+                LOG, "vmtoolsd failed to get guestinfo.ovfEnv: %s", error
+            )
+
+    return None
 
 
 def find_child(node, filter_func):
@@ -287,7 +353,6 @@ def find_child(node, filter_func):
 
 
 def get_properties(contents):
-
     dom = minidom.parseString(contents)
     if dom.documentElement.localName != "Environment":
         raise XmlError("No Environment Node")