Using VM Templates and NSX-T for Repeatable Virtual Network Deployments

So far, we've provided the infrastructure for continuous delivery / continuous integration, but it's been for those other guys.

Is that odd?

Let's try using the principles provided for more infrastructure-oriented reasons. Let's build a network lab using NSX-T.

First, we need some form of a mutable router. Normally, that'd be whatever flavor's "in production," but the specific implementation doesn't really matter.

First, we need to outline what basic functionality would need to be in place for this basic image to work:

  • Management Plane isolation: Build a separate "routing table," or VRF for the first applied interface.
  • Automatic connectivity. We should have some way to automatically get network connectivity separate from the "data plane," and perform configuration loading, command invocations, and software lifecycle management.
  • Enable inbound management protocols.

I have built a light configuration to do that here.

Once operational, we will want a good process to keep software up-to-date. Once established with this basic configuration, it'll be possible to SSH into this device and run the update process. Here's how:

 1vyos@vyos:~$ add system image vrf mgmt  
 2Trying to fetch ISO file from  
 3  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current  
 4                                 Dload  Upload   Total   Spent    Left  Speed  
 5100  309M  100  309M    0     0  1424k      0  0:03:42  0:03:42 --:--:-- 1551k  
 6ISO download succeeded.  
 7Checking for digital signature file...  
 8  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current  
 9                                 Dload  Upload   Total   Spent    Left  Speed  
10  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0  
11curl: (22) The requested URL returned error: 404 Not Found  
12Unable to fetch digital signature file.  
13Do you want to continue without signature check? (yes/no) [yes] yes  
14Checking MD5 checksums of files on the ISO image...OK.  
16What would you like to name this image? [1.3-rolling-202010020117]:  
17OK.  This image will be named: 1.3-rolling-202010020117  
18Installing "1.3-rolling-202010020117" image.  
19Copying new release files...  
20Would you like to save the current configuration  
21directory and config file? (Yes/No) [Yes]: Yes  
22Copying current configuration...  
23Would you like to save the SSH host keys from your  
24current configuration? (Yes/No) [Yes]:  
25Copying SSH keys...  
26Running post-install script...  
27Setting up grub configuration...  
29vyos@vyos:~$ show system image  
30The system currently has the following image(s) installed:  
32   1: 1.3-rolling-202010020117 (default boot)  
33   2: 1.3-rolling-202009200118  
34vyos@vyos:~$ reboot  
35Are you sure you want to reboot this system? [y/N] y  
39vyos@vyos:~$ show system image  
40The system currently has the following image(s) installed:  
42   1: 1.3-rolling-202010020117 (default boot) (running image)  
43   2: 1.3-rolling-202009200118  
45vyos@vyos:~$ delete system image  
46Possible completions:  
47  Enter       Execute the current command  
48  1.3-rolling-202009200118  
49                Name of image image to delete  
50  1.3-rolling-202010020117  
52vyos@vyos:~$ delete system image 1.3-rolling-202009200118  
53Are you sure you want to delete the  
54"1.3-rolling-202009200118" image? (Yes/No) [No]: Yes  
55Deleting the "1.3-rolling-202009200118" image...  

Ta-da! new version! We cleaned up the old image for disk space compaction as well.

Our virtual router is built - let's shut it down, and then convert it to a template:


Ready to go!