Contents

vSphere with Tanzu - Troubleshooting HAProxy deployment

Introduction

You may have already heard and read about our latest changes regarding our Kubernetes offering(s) vSphere with Tanzu also former known as vSphere with Kubernetes. Personally, I was totally excited and full of anticipation to make my first hands-on experience with this new deployment option –> vSphere Networking as an alternative to NSX-T and how HAProxy is doing it’s job within this construct. I don’t know how you are dealing with installations of the “NEW” but I always read the documentation first… … not … ๐Ÿ™Š … but I should!

Honestly! Doesn’t matter of which kind of implementation we are talking, is it a Homelab (test environment), a Proof of Concept implementation or in production, our final goal is a working solution and this is why we should be prepared best. Through this article, I will even more stress this point because I did a mistake which did cost me time in troubleshooting the failure I’ve received. On the other hand and “as always”, it enlightened me and enriched my wealth of experience.

Thank You
I want to give James Lepthien a big thanks for all of his help and guidance. He’s my first go-to person when it comes to all networking related topics.

Preperations

This article will not describe the vSphere with Tanzu installation itself. For this kind of details, I would like to point you to VMware’s official documentation or to this vSphere with Tanzu Quick Start Guide V1a (for evaluation purposes) which VMware is maintaining on the Cloud Platform Tech Zone.

Also! For being prepared better as well as for documentation purposes, we are providing a checklist-file which can be downloaded through the Workload Management section in the vSphere Client and then shared or forwarded to the networking engineer of your confidence (Figure I).

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Figure I: Network Stack Checklist

Resources

The Frontend Network

Step 6 in the Quick Start Guide describes the deployment of the HAProxy Virtual Appliance on vSphere. OVA deployment step 7 gives us the ability to deploy HAProxy with an additional network interface to seperate the Kubernetes nodes of our clusters from the network used by clients or services to access these clusters (Figure II).

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Figure II: Option to choose Frontend Network
Frontend Network Description
Description Deploy the Appliance with 3 nics: a Management network (Supervisor -> HAProxy dataplane), a single Workload network and a dedicated Frontend network. Load-balanced IPs are assigned on the Frontend network.

The configuration of the additional Frontend network is not covered through the aforementioned Quick Start Guide (for simplicity reasons) but if you are going to deploy vSphere with Tanzu into production, it definitely should be used.

I tried to simplify the traffic flow coming from the client and/ or service through the Kubernetes clusters roughly via the following chart:

It must be a valid Subnetwork

OVA deployment step 2.7 requests the static IP address for the Frontend interface and this IP must be outside of the Load Balancer IP Range which you have to define in the next step 3.1. Furthermore, this IP range should not overlap with the assigned IP address of the Frontend network interface as well as with any other VMs in this range!

I’ve misinterpreted the description for Loadbalancer IP ranges in step 3.1 (see Figure III) which I should have “painfully” realised after the complete deployment.

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Figure III: Wrong configuration

At this point, I’d like to make a little excursion in networking 101 to make sure you also see my mistake which I’ve made through this misinterpretation. I entered 10.10.18.18/28 as an IP range which isn’t a valid Subnetwork. A valid subnetwork configuration for my evaluation deployment should have looked like:

Description Address
Network ID 10.10.18.16
Broadcast 10.10.18.31
Netmask 255.255.255.240
Host IP starts with 10.10.18.17
Host IP ends with 10.10.18.30

10.10.18.16/28 is valid and because I decided to use a /28 network, the available IPs for the virtual server range, which you have to provide in Step 5 in the Workload Management configuration (Figure IV) later on, starts with .17 and ends with .30.

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Figure IV: Load Balancer Configuration Workload Management Wizard

The following table gives you a quick overview of available Host IPs for a specific subnetwork.

Subnet Mask /29 /28 /27 /26 /25 /24
Host IPs 6 14 30 62 162 254

* I excluded Network-ID and Broadcast-ID


Don’t be confused

The following has nothing to do with the actual problem but the hint could avoid an uncertainty. Figure V shows the configuration summary of Step 5 and Ingress CIDR/ IP Ranges: 10.10.18.19/11 (in my example) could be confusing because of the CIDR notation.

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Figure V: Load Balancer Configuration Workload Management Wizard

What it shows, is the first IP - .19 - and the maximum number of remaining IPs - /11 - for your defined IP Ranges for Virtual Servers.


Connect: No route to host.

At first sight, the installation seems to be successful and the Cluster Config Status in the vSphere client doesn’t indicate the opposite (Figure VI).

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Figure VI: Workload Management Status

But appearances are deceptive! I created a vSphere Namespace to deploy a Tanzu Kubernetes Cluster (Guest Cluster) and clicked on the OPEN button/ link to the CLI tools (Figure VII) to check the reachability of my Supervisor Cluster and got an ERR_ADDRESS_UNREACHABLE back.

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Figure VII: Link to CLI Tools

Of course that made me suspicious and I tried to login via kubectl vsphere login:

kubectl vsphere login --insecure-skip-tls-verify --vsphere-username administrator@jarvis.lab --server=10.10.18.19

and got the following error:

ERROR
ERRO[0005] Error occurred during HTTP request: Get https://10.10.18.19/wcp/loginbanner: dial tcp 10.10.18.19:443: connect: no route to host There was an error when trying to connect to the server.\n Please check the server URL and try again.FATA[0005] Error while connecting to host 10.10.18.19: Get https://10.10.18.19/wcp/loginbanner: dial tcp 10.10.18.19:443: connect: no route to host.

HAProxy Frontend VIP bind service

Having a look at my above drawing it shows us that our incoming request tries to reach the Frontend VIP 10.10.18.19 trough HAProxy. Because HAProxy is providing those VIP’s, it’s logical to start troubleshooting the HAProxy appliance first. SSH is enabled by default.

I started with a simple status check of all services by executing systemctl status. The output was surprisingly degraded.

Let`s narrow it down!

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root@haproxy [ / ]# systemctl list-units --state=failed

  UNIT                 LOAD   ACTIVE SUB    DESCRIPTION
โ— anyip-routes.service loaded failed failed anyip-routes.service

โ— haproxy.service      loaded failed failed HAProxy Load Balancer

โ— route-tables.service loaded failed failed route-tables.service

Three services have failed to start. I’m starting from the top with verifying the anyip-routes.service.

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root@haproxy [ / ]# systemctl status anyip-routes.service

โ— anyip-routes.service
   Loaded: loaded (/etc/systemd/system/anyip-routes.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Fri 2020-11-20 15:30:07 UTC; 3min 5s ago
  Process: 783 ExecStopPost=/var/lib/vmware/anyiproutectl.sh down (code=exited, status=0/SUCCESS)
  Process: 777 ExecStartPre=/var/lib/vmware/anyiproutectl.sh up (code=exited, status=2)
  Process: 776 ExecStartPre=/bin/mkdir -p /var/log/vmware (code=exited, status=0/SUCCESS)

Nov 20 15:30:07 haproxy.jarvis.lab systemd[1]: Starting anyip-routes.service...
Nov 20 15:30:07 haproxy.jarvis.lab anyiproutectl.sh[777]: adding route for 10.10.18.18/28
Nov 20 15:30:07 haproxy.jarvis.lab anyiproutectl.sh[777]: RTNETLINK answers: Invalid argument
Nov 20 15:30:07 haproxy.jarvis.lab systemd[1]: anyip-routes.service: Control process exited, code=exited status=2
Nov 20 15:30:07 haproxy.jarvis.lab systemd[1]: anyip-routes.service: Failed with result 'exit-code'.
Nov 20 15:30:07 haproxy.jarvis.lab systemd[1]: Failed to start anyip-routes.service.

The mentioned script in this line Process: 783 ExecStopPost=/var/lib/vmware/anyiproutectl.sh down (code=exited, status=0/SUCCESS) seems to do something and by reviewing it, I found the following hint to the configuration file location for the broken service.

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[...]

# The path to the config file used by this program.
CONFIG_FILE="${CONFIG_FILE:-/etc/vmware/anyip-routes.cfg}"

[...]
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root@haproxy [ /etc/vmware ]# cat anyip-routes.cfg

#
# Configuration file that contains a line-delimited list of CIDR values
# that define the network ranges used to bind the load balancer's frontends
# to virtual IP addresses.
#
# * Lines beginning with a comment character, #, are ignored
# * This file is used by the anyip-routes service
#
10.10.18.18/28

Verifying the file and thus my made configuration finally brought me enlightenment. I changed it consequently from 10.10.18.18/28 to a valid Subnetwork range, which is the already mentioned 10.10.18.16/28 and rebooted the HAProxy appliance (reboot). Just restarting the service with systemctl restart anyip-routes.service does not apply all necessary changes.

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Figure VIII: Adjusted anyip-routes.cfg file | reboot appliance | ping Supervisor VIP

Finally, the validation of the restored functionality:

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kubectl vsphere login --insecure-skip-tls-verify --vsphere-username administrator@jarvis.lab --server=10.10.18.19

Password:
Logged in successfully.

You have access to the following contexts:
   10.10.18.19
   tkg-app

If the context you wish to use is not in this list, you may need to try
logging in again later, or contact your cluster administrator.

To change context, use `kubectl config use-context <workload name>
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Figure IX: Validating Supervisor VIP reachability
Done โœ…