Getting Started with vCloud Director, VMware Remote Console Proxy and VMware Remote Console Plugin (Part 2)

In Part 1 of this post, I inroduced the components of the VMware console proxy,  remote console proxy, and how they work with vCloud Director. In Part 2,  I'll cover resiliency of the remote console proxy, what ports are  required, operations available to the user, and run through  troubleshooting and tools.

7. How Resilient is the Remote Console Proxy?

The  VMware Remote Console Proxy Plugin actually opens four different  connections to the Console Proxy for a single Remote Console session  (three for the vCenter server, one for the ESX/ESXi server). The Console  Proxy is stateless, and therefore the Load Balancer can route each of  those four connections to different Console Proxies and the system would  still work perfectly fine. If a connection is dropped for some reason  (e.g. the Console Proxy dies), then the VMware Remote Console Proxy  automatically tries to re-establish it and the Load Balancer can route  it through a different Console Proxy. The user should not notice  anything but a small delay.

8. What ports are required to be open for the Remote Console Proxy to function correctly?

The  vCD Console Proxy Plugin communicates with the vCD server only on port  443 via the Console Proxy. That is the only port that is required to be  open and accessible from the Internet.

9. What operations are available to a user of the Remote Console Proxy?

The following functionality is exposed by the VMware Remote Console Proxy and presented and consumed in VMware vCloud Director:

• If  the Virtual Machine (VM) is powered off and you connect the VMware  Remote Console Proxy to it, it will implicitly power it on.
• Power Off the Virtual Machine (VM).
• Reset the Virtual Machine (VM).
• Suspend the Virtual Machine (VM).
• If the Virtual Machine (VM) is suspended, it will implicitly resume it on initial connection, similar to power on.
• Remote MKS interactions, including grabbing / un-grabbing input, and explicitly sending Ctrl+Alt+Del to the guest.
• Full screen support.
• Remote device support for CD-ROMs and floppies, whether physical or backed by file images, which exists on the client machine.
• Technically, it will let you connect these devices as server-side as well.
• If  the Virtual Machine (VM) temporarily disconnects, such, as during  reverting to a snapshot or the MKS connection is lost, the VMware Remote  Console will try to re-connect.

The  VMware Remote Console Proxy behaviour is to automatically power on and  resume the Virtual Machine (VM), if it is powered off or suspended when  you open a console to it. However, vCD allows you to open a console of a  Virtual Machine (VM), only if the state of the Virtual Machine (VM) is  powered off. This behaviour is enforced by vCD and not the VMware Remote  Console Proxy.

10. Troubleshooting

Here are some of the most common things to check if for some reason you are not able to use the Remote Console Proxy:

• Does  `netstat -nape | grep 443` show a java process listening on the IP  Address that you specified as the (internal) console proxy IP Address  when running the configure script? This should also show port 443 open  on the HTTP service IP.
• Can you telnet to port 443, 902, and 903 on the vCenter server from the vCD server?
• Can you telnet to the public console proxy IP on port 443 from outside of your Load Balancer?
• Do  the VMware Remote Console Plugin logs, which exist on the client, tell  you anything?  On Windows clients, the VMware Remote Console Plugin logs  are typically found in C:\Documents and in Settings\LOGINUSER\Local  Settings\Temp\vmware-LOGINUSER. The file names follow the pattern of  vmware-LOGINUSER-VMWAREVMRCPID.log and  vmware-VMWAREVMRCPID-mks-LOGINUSER-VMWAREREMOTEMKSPID.log. On Unix  clients, the VMware Remote Console Plugin logs are typically found in  /tmp/vmware-LOGINUSER. Again, the file names follow the pattern  vmrc-VMWAREVMRCPID.log and VMWAREVMRCPID-mks VMWAREREMOTEMKSPID.log.
• Do  the Console Proxy logs tell you anything? The Console Proxy logs al its  activity in the same way as the rest of the vCD server. Its logs  therefore can be found in <vCD dir>/logs/vcloud-container-info.log  and vcloud-container-debug.log.

11. Tools

The  following python script can be used to get a Virtual Machine (VM)  console through the VMware Remote Console Proxy. The script expects curl  and vmware-vmrc to be in your path. This script has currently been  tested on Linux and Windows. The latest version of the script, version  1.0.2 is able to work on windows by using python and curl compiled for  windows. In addition to this on Windows we have tested both with and  without the cygwin shell. If you get the following when you try and run  Vmrc-mks.py as follows:

$ python Vmrc-mks.py

Traceback (most recent call last):

  File "Vmrc-mks.py", line 13, in <module>

    import argparse

ImportError: No module named argparse

This is because this script requires Python 2.6 or later and the argparse package, which is not always installed with the default distribution. This can be found at:

http://pypi.python.org/pypi/argparse/1.1

The script performs the following:

- login to vCD

- request screen ticket

- parse the mks://... URL and extract the host/vm moref/ticket

- decode the URL-encoded ticket

- pass proper arguments to vmrc

Script help:

usage: vmrc-mks.py [-h] [-v] -c CREDENTIALS [--curl CURL] [--vmrc VMRC]

acquire_ticket_uri

Script to process and acquire the VM screen ticket from the vCloud REST API.

Positional arguments:

acquire_ticket_uri    URI to acquire ticket action:

https://<vCD Cell Host>/api/v1.0/vApp/vm-265481682/screen/action/acquireTicket

Optional arguments:

  -h, --help            show this help message and exit

  -v, --verbose      verbose messages

  -c CREDENTIALS, --credentials CREDENTIALS

                                  credentials in format user@Org:password

  --curl CURL           point to curl executable, default is "curl"

  --vmrc VMRC           point to vmrc executable, default is "vmware-vmrc"

Example:

vmrc-mks.py -c vcloud@system:vcloud https://10.10.10.2/api/v1.0/vApp/vm-265481682/screen/action/acquireTicket

Conclusion:

Providing  the VMware Remote Console clients (VMRC) functionality in vCD allows  you to access multiple vCenter and ESX/ESXi servers from a single  location. This is useful, as it allows the cloud provider’s to "hide"  the structure of their vCenter servers and ESX/ESXi servers where the  Virtual Machine’s (VMs) are located. In addition to this, the VMware  Remote Console clients are stateless and therefore provide both  scalability and availability.