ebb0af9e8f
Order of Volumes and VolumeMounts in the pod objects created by
kubeadm is undefined as they're represended as maps in the
controlPlaneHostPathMounts struct.
This influences 'kubeadm upgrade' logic in a way that even when
manifest of the component is not changed kubeadm tries to upgrade
it because most of the time current and new pods are not equal
due to the different order of Volumes and VolumeMounts.
For example 'kubeadm apply diff' almost always shows difference
in Volumes and VolumeMounts because of this:
volumeMounts:
+ - mountPath: /etc/kubernetes/pki
+ name: k8s-certs
+ readOnly: true
- mountPath: /etc/ssl/certs
name: ca-certs
+ readOnly: true
+ - mountPath: /etc/pki
+ name: etc-pki
+ readOnly: true
+ - mountPath: /usr/share/ca-certificates
+ name: usr-share-ca-certificates
readOnly: true
- mountPath: /etc/ca-certificates
name: etc-ca-certificates
readOnly: true
- - mountPath: /etc/pki
- name: etc-pki
- readOnly: true
- - mountPath: /etc/kubernetes/pki
- name: k8s-certs
- readOnly: true
- - mountPath: /usr/share/ca-certificates
- name: usr-share-ca-certificates
- readOnly: true
Sorting Volumes and VolumeMounts should fix this issue and help
to avoid unnecessary upgrades.
Kubernetes
Kubernetes is an open source system for managing containerized applications across multiple hosts; providing basic mechanisms for deployment, maintenance, and scaling of applications.
Kubernetes builds upon a decade and a half of experience at Google running production workloads at scale using a system called Borg, combined with best-of-breed ideas and practices from the community.
Kubernetes is hosted by the Cloud Native Computing Foundation (CNCF). If you are a company that wants to help shape the evolution of technologies that are container-packaged, dynamically-scheduled and microservices-oriented, consider joining the CNCF. For details about who's involved and how Kubernetes plays a role, read the CNCF announcement.
To start using Kubernetes
See our documentation on kubernetes.io.
Try our interactive tutorial.
Take a free course on Scalable Microservices with Kubernetes.
To start developing Kubernetes
The community repository hosts all information about building Kubernetes from source, how to contribute code and documentation, who to contact about what, etc.
If you want to build Kubernetes right away there are two options:
You have a working Go environment.
$ go get -d k8s.io/kubernetes
$ cd $GOPATH/src/k8s.io/kubernetes
$ make
You have a working Docker environment.
$ git clone https://github.com/kubernetes/kubernetes
$ cd kubernetes
$ make quick-release
For the full story, head over to the developer's documentation.
Support
If you need support, start with the troubleshooting guide, and work your way through the process that we've outlined.
That said, if you have questions, reach out to us one way or another.