Kubernetes Integration "Something went wrong while installing Helm Tiller"

Infrastructure as Code & Cloud Native
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6

I’ve installed another single-node “cluster” to test GitLab integration with Kubernetes following the official guide with kubeadm [1].

According to the official documentation, the API URL is only https://hostname:port without trailing slash.

First, I listed the secrets as usual:

$ kubectl get secrets
NAME                           TYPE                                  DATA      AGE
default-token-tpvsd            kubernetes.io/service-account-token   3         2d
k8s-dashboard-sa-token-XXXXX   kubernetes.io/service-account-token   3         1d

Then I got the CA certificate directly from the JSON output via jq with a custom selector:

$ kubectl -o json get secret k8s-dashboard-sa-token-XXXXX | jq -r '.data."ca.crt"' | base64 -d - | tee ca.crt
-----BEGIN CERTIFICATE-----
MIICyDCCAbCgAwIBAgIBADANBgkqhkiG9w0BAQsFADAVMRMwEQYDVQQDEwprdWJl
	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
FT55iMtPtFqAOnoYBCiLH6oT6Z1ACxduxPZA/EeQmTUoRJG8joczI0V1cnY=
-----END CERTIFICATE-----

After this, I could verify the CA certificate as usual:

$ openssl x509 -in ca.crt -noout -subject -issuer
subject= /CN=kubernetes
issuer= /CN=kubernetes

$ openssl s_client -showcerts -connect 192.168.100.20:6443 < /dev/null &> apiserver.crt

$ openssl verify -verbose -CAfile ca.crt apiserver.crt
apiserver.crt: OK

Happy hacking!

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