Skip to content

Latest commit

 

History

History
97 lines (61 loc) · 3.43 KB

cka-tips.md

File metadata and controls

97 lines (61 loc) · 3.43 KB
Raw

CKA Tips

CKA Syllabus

Read the official CKA certification page especially for:

  • candidate handbook
  • curriculum

Vim & bash preferences

:autocmd FileType yaml setlocal ai ts=2 sw=2 et nu rnu

also useful in some situations:

:syntax on
:set syntax=whitespace

For Macbook Pro users with touch-bar, it can be useful to map the Caps lock key to ESC.

Browser preferences

Add Chrome search engine to speed up searches. Go to Settings | Manage search Engines to add a search engine. I use:

Imperative management

Use kubectl create or run to create and modify objects as opposed to declarative apply - it is much faster.

In some cases, reference existing objects via config files, or kubectl get -o yaml to create new ones. e.g. Daemonsets, new kube-scheduler, etc.

If a tempate from docs.kubernetes is required (e.g. persistent volume), try curling the yaml link in the web document: curl -LO https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/pods/storage/pv-volume.yaml

For application lifecycle management, use both kubectl set or edit.

Speed up deletions by using --grace-period=1

OpenSSL

To view certificate info:

openssl x509 -in $INFILE -text -noout

(Not tested) To sign new certificate, pass the CSR and CA pair:

openssl x509 req -in $CSR \
-CA $CACERT
-CAkey $CAkey
-CAcreateserial
-out $NEWCERT

Mummshad's Kubernetes the hard way

  • VMware Fusion can be used - the Vagrantfile in this repo has been extended to use it: vagrant up --provider=vmware_fusion.

  • For some reason, it was configured that the load balancer VM's hostname is loadbalancer. It is however, not pingable - the /etc/hosts file shows the host lb instead.

  • enp0s8 may not be available with some configurations, especially in VMware fusion: ip addr should show the correct interface of internal range 192.x instead - e.g. eth1.

  • kubelet will not start with swap error in /var/log/syslog or journalctl -u kubelet. Remember to turn off swap in worker nodes via:

sudo sed -i.bak '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
sudo swapoff -a

  • there may be changes to the api, especially during configuration for coredns - use apps/v1 for kind: Deployment instead of extensions/v1beta1 if attempting to deploy later versions of kubernetes, eg. 1.16.x

  • using kubectl get componentstatuses may result in empty results, esp. for 1.16.0.

  • e2e test issue workaround: kubernetes/test-infra#14712

  • if port-forward issues are seen after OSX Catalina upgrade or VMware Fusion upgrade, e.g.

Vagrant failed to apply the requested port forward. The following
error message was generated while attempting to apply the port
forward rule:

  Port forward conflict on host port 2730

try cleaning up the vagrant-vmware NAT settings.

Other Tips

Interesting study guides: David-VTUK stretchcloud CKAD