b296f82c69
There is a corner case when blocking Pod termination via a lifecycle
preStop hook, for example by using this StateFulSet:
```yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: web
spec:
selector:
matchLabels:
app: ubi
serviceName: "ubi"
replicas: 1
template:
metadata:
labels:
app: ubi
spec:
terminationGracePeriodSeconds: 1000
containers:
- name: ubi
image: ubuntu:22.04
command: ['sh', '-c', 'echo The app is running! && sleep 360000']
ports:
- containerPort: 80
name: web
lifecycle:
preStop:
exec:
command:
- /bin/sh
- -c
- 'echo aaa; trap : TERM INT; sleep infinity & wait'
```
After creation, downscaling, forced deletion and upscaling of the
replica like this:
```
> kubectl apply -f sts.yml
> kubectl scale sts web --replicas=0
> kubectl delete pod web-0 --grace-period=0 --force
> kubectl scale sts web --replicas=1
```
We will end up having two pods running by the container runtime, while
the API only reports one:
```
> kubectl get pods
NAME READY STATUS RESTARTS AGE
web-0 1/1 Running 0 92s
```
```
> sudo crictl pods
POD ID CREATED STATE NAME NAMESPACE ATTEMPT RUNTIME
e05bb7dbb7e44 12 minutes ago Ready web-0 default 0 (default)
d90088614c73b 12 minutes ago Ready web-0 default 0 (default)
```
When now running `kubectl exec -it web-0 -- ps -ef`, there is a random chance that we hit the wrong
container reporting the lifecycle command `/bin/sh -c echo aaa; trap : TERM INT; sleep infinity & wait`.
This is caused by the container lookup via its name (and no podUID) at:
|
||
|---|---|---|
| .github | ||
| api | ||
| build | ||
| CHANGELOG | ||
| cluster | ||
| cmd | ||
| docs | ||
| hack | ||
| LICENSES | ||
| logo | ||
| pkg | ||
| plugin | ||
| staging | ||
| test | ||
| third_party | ||
| vendor | ||
| .generated_files | ||
| .gitattributes | ||
| .gitignore | ||
| .golangci.yaml | ||
| CHANGELOG.md | ||
| code-of-conduct.md | ||
| CONTRIBUTING.md | ||
| go.mod | ||
| go.sum | ||
| LICENSE | ||
| Makefile | ||
| OWNERS | ||
| OWNERS_ALIASES | ||
| README.md | ||
| SECURITY_CONTACTS | ||
| SUPPORT.md | ||
Kubernetes (K8s)
Kubernetes, also known as K8s, is an open source system for managing containerized applications across multiple hosts. It provides 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 your company 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 K8s
See our documentation on kubernetes.io.
Try our interactive tutorial.
Take a free course on Scalable Microservices with Kubernetes.
To use Kubernetes code as a library in other applications, see the list of published components.
Use of the k8s.io/kubernetes module or k8s.io/kubernetes/... packages as libraries is not supported.
To start developing K8s
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.
mkdir -p $GOPATH/src/k8s.io
cd $GOPATH/src/k8s.io
git clone https://github.com/kubernetes/kubernetes
cd 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.
Community Meetings
The Calendar has the list of all the meetings in Kubernetes community in a single location.
Adopters
The User Case Studies website has real-world use cases of organizations across industries that are deploying/migrating to Kubernetes.
Governance
Kubernetes project is governed by a framework of principles, values, policies and processes to help our community and constituents towards our shared goals.
The Kubernetes Community is the launching point for learning about how we organize ourselves.
The Kubernetes Steering community repo is used by the Kubernetes Steering Committee, which oversees governance of the Kubernetes project.
Roadmap
The Kubernetes Enhancements repo provides information about Kubernetes releases, as well as feature tracking and backlogs.