Tag Archives: Certificate

Kubernetes

Kubernetes Metric Server – cannot validate certificate because it doesn’t contain any IP SANs

Kubernetes, , , , , ,

The Issue

Whilst trying to install the Metric’s server:

kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

so I could use kubectl top node for it’s metrics on Node resource useage, I found the pods were not loading, and upon inspection found the following:

> kubectl logs -n kube-system metrics-server-6f6cdbf67d-v6sbf 

I0717 12:19:32.132722 1 server.go:187] "Failed probe" probe="metric-storage-ready" err="no metrics to serve"
E0717 12:19:39.159422 1 scraper.go:140] "Failed to scrape node" err="Get \"https://192.168.49.2:10250/metrics/resource\": x509: cannot validate certificate for 192.168.49.2 because it doesn't contain any IP SANs" node="minikube"

The Cause

The issue here was due to the installation of Cert-Manager and setting up some TLS configurations within the CNI and Self-Signed certificates, the metric’s server wasn’t able to validate the authority of the Kubernetes API

The Fix

As this is communication within the cluster, I could simply fix this by telling Metric Server container to trust the insecure certificates from the API using the below
kubectl patch command:

kubectl patch deployment metrics-server -n kube-system --type='json' -p='[{"op": "add", "path": "/spec/template/spec/containers/0/args/-", "value": "--kubelet-insecure-tls"}]'

 

Regards

Dean Lewis

Tanzu Blog Logo Header

Tanzu Kubernetes Grid – Manual Certificate Renewal

VMware, Kubernetes, , , ,
The Issue
Note: VMware has released a full in-depth KB Article that I'd advise you review along with this blog post. If you have any queries or concerns with the processes detailed, always open a support ticket!
- How to rotate certificates in a Tanzu Kubernetes Grid cluster (86251)

One day my Kubernetes cluster just stopped responding. I could no longer connect to the Kubernetes API.

I rebooted all the nodes (as it was a demo environment) to no luck, and still nothing. So I had to go off digging.

The Cause

I SSH’d into one of my control-plane nodes, and started to tail the kubelet logs. Continue reading Tanzu Kubernetes Grid – Manual Certificate Renewal →

vRA 8.0 header

vRealize Automation 8.0 – Wildcard SSL certificate support and deployment issues – LCMVRAVACONFIG590003

VMware, , , , , , , ,

Ok, so I’m just going to call it out straight away, when using wildcard SSL certificates with vRealize Automation 8.0, read the release notes.

I did not, and caused myself quite a few headaches with the deployment, which you can read about further in this post.

Cannot set wildcard certs for certain domain names, specifically those not using a Public Suffix.

vRealize Automation 8.0 supports setting a wildcard certificate only for DNS names that match the content of the Public Suffix List ([https://publicsuffix.org/]) 

For example, a valid wildcard certificate: you can use a wildcard certificate with DNS name like "*.myorg.com". This is supported because "com" is part of the Public Suffix List. 

An invalid wildcard certificate example: you cannot use a wildcard certificate with DNS name like "*.myorg.local".This is not supported because "local" is not part of Public Suffix List. 

Workaround: Only use domain names in the Public Suffix List.

The issues caused by using an unsupported wildcard SSL

When deploying vRA 8.0 via vRSLCM, either as part of the easy installer or as part of an existing vRSLCM setup, you will asked to provide an SSL certificate.

This does not validate your certificate is supported for use with the vRA 8.0 deployment. vRSLCM will do some checking on the SSL selected, but is only to ensure the SSL certificate is not about to expire, you will see a Green tick and “healthy” status as below.

vRA deployment SSL issue LCMVRAVACONFIG590003 wild card cert

Once you hit deploy, you will find your vRA appliance finally stood up, however the initialization tasks will stall.

Error Code: LCMVRAVACONFIG590003
Cluster Initialization failed on VRA.

vRA Initialize Cluster failed on vRA VA - ***Hostname***. Please login to the vRA and check /var/log/deploy.log file for more information on failure.

Continue reading vRealize Automation 8.0 – Wildcard SSL certificate support and deployment issues – LCMVRAVACONFIG590003 →