mirror of https://github.com/k3s-io/k3s
49626c975b
Automatic merge from submit-queue Statefulsets for cinder: allow multi-AZ deployments, spread pods across zones **What this PR does / why we need it**: Currently if we do not specify availability zone in cinder storageclass, the cinder is provisioned to zone called nova. However, like mentioned in issue, we have situation that we want spread statefulset across 3 different zones. Currently this is not possible with statefulsets and cinder storageclass. In this new solution, if we leave it empty the algorithm will choose the zone for the cinder drive similar style like in aws and gce storageclass solutions. **Which issue this PR fixes** fixes #44735 **Special notes for your reviewer**: example: ``` kind: StorageClass apiVersion: storage.k8s.io/v1beta1 metadata: name: all provisioner: kubernetes.io/cinder --- apiVersion: v1 kind: Service metadata: annotations: service.alpha.kubernetes.io/tolerate-unready-endpoints: "true" name: galera labels: app: mysql spec: ports: - port: 3306 name: mysql clusterIP: None selector: app: mysql --- apiVersion: apps/v1beta1 kind: StatefulSet metadata: name: mysql spec: serviceName: "galera" replicas: 3 template: metadata: labels: app: mysql annotations: pod.alpha.kubernetes.io/initialized: "true" spec: containers: - name: mysql image: adfinissygroup/k8s-mariadb-galera-centos:v002 imagePullPolicy: Always ports: - containerPort: 3306 name: mysql - containerPort: 4444 name: sst - containerPort: 4567 name: replication - containerPort: 4568 name: ist volumeMounts: - name: storage mountPath: /data readinessProbe: exec: command: - /usr/share/container-scripts/mysql/readiness-probe.sh initialDelaySeconds: 15 timeoutSeconds: 5 env: - name: POD_NAMESPACE valueFrom: fieldRef: apiVersion: v1 fieldPath: metadata.namespace volumeClaimTemplates: - metadata: name: storage annotations: volume.beta.kubernetes.io/storage-class: all spec: accessModes: [ "ReadWriteOnce" ] resources: requests: storage: 12Gi ``` If this example is deployed it will automatically create one replica per AZ. This helps us a lot making HA databases. Current storageclass for cinder is not perfect in case of statefulsets. Lets assume that cinder storageclass is defined to be in zone called nova, but because labels are not added to pv - pods can be started in any zone. The problem is that at least in our openstack it is not possible to use cinder drive located in zone x from zone y. However, should we have possibility to choose between cross-zone cinder mounts or not? Imo it is not good way of doing things that they mount volume from another zone where the pod is located(means more network traffic between zones)? What you think? Current new solution does not allow that anymore (should we have possibility to allow it? it means removing the labels from pv). There might be some things that needs to be fixed still in this release and I need help for that. Some parts of the code is not perfect. Issues what i am thinking about (I need some help for these): 1) Can everybody see in openstack what AZ their servers are? Can there be like access policy that do not show that? If AZ is not found from server specs, I have no idea how the code behaves. 2) In GetAllZones() function, is it really needed to make new serviceclient using openstack.NewComputeV2 or could I somehow use existing one 3) This fetches all servers from some openstack tenant(project). However, in some cases kubernetes is maybe deployed only to specific zone. If kube servers are located for instance in zone 1, and then there are another servers in same tenant in zone 2. There might be usecase that cinder drive is provisioned to zone-2 but it cannot start pod, because kubernetes does not have any nodes in zone-2. Could we have better way to fetch kubernetes nodes zones? Currently that information is not added to kubernetes node labels automatically in openstack (which should I think). I have added those labels manually to nodes. If that zone information is not added to nodes, the new solution does not start stateful pods at all, because it cannot target pods. cc @rootfs @anguslees @jsafrane ```release-note Default behaviour in cinder storageclass is changed. If availability is not specified, the zone is chosen by algorithm. It makes possible to spread stateful pods across many zones. ``` |
||
|---|---|---|
| .github | ||
| Godeps | ||
| api | ||
| build | ||
| cluster | ||
| cmd | ||
| docs | ||
| examples | ||
| federation | ||
| hack | ||
| hooks | ||
| logo | ||
| pkg | ||
| plugin | ||
| staging | ||
| test | ||
| third_party | ||
| translations | ||
| vendor | ||
| .bazelrc | ||
| .gazelcfg.json | ||
| .generated_files | ||
| .gitattributes | ||
| .gitignore | ||
| BUILD.bazel | ||
| CHANGELOG.md | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| Makefile | ||
| Makefile.generated_files | ||
| OWNERS | ||
| OWNERS_ALIASES | ||
| README.md | ||
| Vagrantfile | ||
| WORKSPACE | ||
| code-of-conduct.md | ||
| labels.yaml | ||
README.md
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
If you are less impatient, 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.