Julien Chen

I tried using k8s offered by Docker Desktop to do some experiment. But I found the hpa kept showing target unknown to me…

According these 2 posts: Docker Kubernetes (Mac) — Autoscaler unable to find metrics”, “Get metrics from pod with docker for mac. It turned out it’s the metrics-server’s problem.

You can find the latest matrics-server release here, and add “--kubelet-insecure-tls” to the args of the Deployment configuration.

- args:
- --cert-dir=/tmp
- --secure-port=4443
- --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
- --kubelet-use-node-status-port
- --kubelet-insecure-tls
image: k8s.gcr.io/metrics-server/metrics-server:v0.4.4

And then apply it.

kubectl apply -f components.yaml

Now, your hpa can get metrics.



Recently I am trying to ship some springboot projects to kubernetes. So I chose Helm to manage my k8s setting. But when I tried to use Helm to install my chart. I kept getting connection refused error. I stuck on this problem for a long time…

connection refused warning

Turns out embedded Tomcat of Springboot only listen localhost(

After add the below setting to application.properties, the problem was solved.


P.S. Besides the above setting, please check if your API return HTTP status code or not. Liveness/Readiness probes can get health is according 400>HTTP status code ≥200. Not if you API have response or not.