karmada-io/karmada v1.2.0 on GitHub

What's New

Significant improvement on scheduling capability and scalability

1. Karmada Descheduler

A new component karmada-descheduler was introduced, for rebalancing the scheduling decisions over time.
One example use case is: it helps evict pending replicas (Pods) from resource-starved clusters so that karmada-scheduler can "reschedule" these replicas (Pods) to a cluster with sufficient resources.
For more details please refer to Descheduler user guide.

(Feature contributor: @Garrybest)

2. Multi region HA support

By leveraging the newly added spread-by-region constraint, users are now able to deploy workloads aross regions, e.g. people may want their workloads always running on different regions for HA purposes.
We also introduced two plugins to karmada-scheduler, which add to accurate scheduling.

ClusterLocality is a scoring plugin that favors clusters already assigned.
SpreadConstraint is a filter plugin that filters clusters as per spread constraints.

(Feature contributors: @huone1, @gf457832386)

We are also in the progress of enhancing the multi-cluster failover mechanism. Part of the work has been included in this release.
For example:

A new flag(--cluster-failure-threshold) has been added to both karmada-controller-manager and karmada-agent, which specifies the cluster failure threshold (defaults to 30s). A cluster will be considered not-ready only when it stays unhealthy longer than supposed.
A new flag(--failover-eviction-timeout) has been added to karmada-controller-manager, which specifies the grace period of eviction (defaults to 5 minutes). If a cluster stays not-ready longer than supposed, the controller taints the cluster. (Note: The taint is essentially the eviction order and the implementation is planned for the next release.)

(Feature contributors: @Garrybest, @dddddai)

Fully adopted aggregated API

The Aggregated API was initially introduced in Release 1.0, which allows users to access clusters through Karmada by a single aggregated API endpoint. By leveraging this feature, we introduced a lot of interesting features to karmadactl and kubectl-karmada.

1. The `get` sub-command now supports clusters both in `push` and `pull` mode.

# karmadactl get deployment -n default
NAME      CLUSTER   READY   UP-TO-DATE   AVAILABLE   AGE     ADOPTION
nginx     member1   2/2     2            2           33h     N
nginx     member2   1/1     1            1           4m38s   Y
podinfo   member3   2/2     2            2           27h     N

2. The newly added `logs` command prints the container logs in a specific cluster.

# ./karmadactl logs nginx-6799fc88d8-9mpxn -c nginx  -C member1
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
...

3. We also added `watch` and `exec` commands to `karmadactl`, in addition to `get` and `logs`. They all use the aggregated API.

(Feature contributor: @lonelyCZ)

Distributed search and analytics engine for Kubernetes resources (`alpha`)

The newly introduced karmada-search caches resources in clusters and allows users to search for resources without directly touching real clusters.

# kubectl get --raw /apis/search.karmada.io/v1alpha1/search/cache/apis/apps/v1/deployments
{
	"apiVersion": "v1",
	"kind": "List",
	"metadata": {},
	"items": [{
		"apiVersion": "apps/v1",
		"kind": "Deployment",
		"metadata": {
			"annotations": {
				"cluster.karmada.io/name": "member1",
			},
		}
	},
	]
}

The karmada-search also supports syncing cached resources to backend stores like Elasticsearch or OpenSearch. By leveraging the search engine, you can perform full-text searches with all desired features, by field, and by indice; rank results by score, sort results by field, and aggregate results.

(Feature contributors: @huntsman-li, @liys87x)

Resource Interpreter Webhook enhancement

Introduced InterpretStatus for the Resource Interpreter Webhook framework, which enables customized resource status collection.
Karmada can thereby learn how to collect status for your resources, especially custom resources. For example, a custom resource may have many status fields and only Karmada can collect only those you want.

Refer to [Customizing Resource Interpreter][https://github.com/karmada-io/karmada/blob/master/docs/userguide/customizing-resource-interpreter.md] for more details.

(Feature contributor: @XiShanYongYe-Chang)

Integrating verification with the ecosystem

Benefiting from the Kubernetes native APIs, Karmada can easily integrate the Kubernetes ecosystem. The following components are verified by the Karmada community:

Kyverno: policy engine. Refer to working with kyverno for more details.
Gatekeeper: another policy engine. Refer to working with gatekeeper for more details.
fluxcd: GitOps tooling for helm chart. Refer to working with fluxcd for more details.

(Feature contributors: @Poor12, @learner0810)

Other Notable Changes

Bug Fixes

karmadactl: Fixed the cluster joining failures in the case of legacy secrets. (@zgfh, #1306)
karmadactl: Fixed the issue that you cannot use the '-v 6' log level. (@zgfh, #1426)
karmadactl: Fixed the issue that the --namespace flag of init command did not work. (@sayaoailun, #1416)
karmadactl: Allowed namespaces to be customized. (@sayaoailun, #1449)
karmadactl: Fixed the init failure due to data path not clean. (@prodanlabs, #1455)
karmadactl: Fixed the init failure to read the KUBECONFIG environment variable. (@lonelyCZ, #1437)
karmadactl: Fixed the init command failure to select the default release version. (@prodanlabs, #1456)
karmadactl: Fixed the issue that the karmada-system namespace already exists when deploying karmada-agent. (@hanweisen, #1604)
karmadactl: Fixed the issue that the karmada-controller-manager args did not honor customized namespaces.` (@prodanlabs, #1683)
karmadactl: Fixed a panic due to nil annotation when promoting resources to Karmada.` (@duanmengkk, #1759)
karmadactl: Fixed the promote command failure to migrate cluster-scoped resources. (@duanmengkk, #1766)
karmadactl: fixed the karmadactl taint failure while the karmada control plane config is not located in the default path. (@wuyingjun-lucky, #1825)
helm-chart: Fixed the karmada-agent installation failure due to the lack of permission. (@AllenZMC, #1457)
helm-chart: Fixed the issue that version constraints skip pre-releases. (@pigletfly, #1444)
karmada-controller-manager: Fixed the issue that ResourceBinding may hinder en-queue in the case of schedule failures. (@mrlihanbo, #1499)
karmada-controller-manager: Fixed the panic when the interpreter webhook returns nil patch. (@CharlesQQ, #1584)
karmada-controller-manager: Fixed the RB/CRB controller failure to aggregate status in the case of work condition update. (@mrlihanbo, #1513)
karmada-aggregate-apiserver: Fixed timeout issue when requesting cluster/proxy with options -w or logs -f from karmadactl get. (@XiShanYongYe-Chang, #1620)
karmada-aggregate-apiserver: Fixed exec failed: error: unable to upgrade connection: you must specify at least 1 of stdin, stdout, stderr. (@pangsq, #1632)

Features & Enhancements

karmada-controller-manager: Introduced several flags to specify controller's concurrent capacities(--rate-limiter-base-delay, --rate-limiter-max-delay, --rate-limiter-qps, --rate-limiter-bucket-size). (@pigletfly, #1399)
karmada-controller-manager: The klog flags now have been grouped for better readability. (@RainbowMango, #1468)
karmada-controller-manager: Fixed the FullyApplied condition of ResourceBinding/ClusterResourceBinding mislabeling issue in the case of non-scheduling. (@huone1, #1512)
karmada-controller-manager: Added default AggregateStatus webhook for DaemonSet and StatefulSet. (@Poor12, #1586)
karmada-controller-manager: OverridePolicy with empty ResourceSelector will be considered to match all resources just like nil. (@likakuli, #1706)
karmada-controller-manager: Introduced --failover-eviction-timeout to specify the grace period of eviction. Tants(cluster.karmada.io/not-ready or cluster.karmada.io/unreachable) will be set on unhealthy clusters after the period. (@Garrybest, #1781)
karmada-controller-manager/karmada-agent: Introduced --cluster-failure-threshold flag to specify cluster failure threshold. (@dddddai, #1829)
karmada-scheduler: Workloads can now be rescheduled after the cluster is unregistered. (@huone1, #1383)
karmada-scheduler: The klog flags now have been grouped for better readability. (@jameszhangyukun, #1491)
karmada-scheduler: Added a scoring plugin ClusterLocality to favor clusters already requested. (@huone1, #1334)
karmada-scheduler: Introduced filter plugin SpreadConstraint to filter clusters that do not meet the spread constraints. (@gf457832386, #1570)
karmada-scheduler: Supported spread constraints by region strategy. (@huone1, #1646)
karmada-webhook: Introduced --tls-cert-file-name and --tls-private-key-file-name flags to specify the server certificate and private key. (@mrlihanbo, #1464)
karmada-agent: The klog flags now have been grouped for better readability. (@lonelyCZ, #1389)
- karmada-agent: Introduced several flags to specify controller's concurrent capacities(--rate-limiter-base-delay, --rate-limiter-max-delay, --rate-limiter-qps, --rate-limiter-bucket-size). (@dddddai, #1505)
karmada-scheduler-estimator: The klog flags now have been grouped for better readability. (@AllenZMC, #1493)
karmadactl: Introduced --context flag to specify the context name to use. (@lonelyCZ, #1748)
karmadactl: Introduced --kube-image-mirror-country and --kube-image-registry flags to init subcommand for Chinese mainland users. (@wuyingjun-lucky, #1764)
karmadactl: Introduced deinit sub-command to uninstall Karmada. (@prodanlabs, #1337)
Introduced Swagger docs for Karmada API. (@lonelyCZ, #1401)

Other (Dependencies)

The base image alpine has been promoted to v3.15.1. (@RainbowMango, #1519)

Deprecation

karmada-controller-manager: The hpa controller is disabled by default now. (@Poor12, #1580)
karmada-aggregated-apiserver: The deprecated flags --karmada-config and --master in v1.1 have been removed from the codebase. (@AllenZMC, #1834)

Contributors

Thank you to everyone who contributed to this release!

Users whose commits are in this release (alphabetically by user name)

karmada-io/karmada v1.2.0 karmada v1.2.0 release on GitHub