'How to uninstall rancher manually?
I installed rancher into existing kubernetes cluster from this tutorial, using these commands:
helm repo add rancher-latest https://releases.rancher.com/server-charts/latest
kubectl create namespace rancher
kubectl apply --validate=false -f https://github.com/jetstack/cert-manager/releases/download/v1.0.4/cert-manager.crds.yaml
helm repo add jetstack https://charts.jetstack.io
helm repo update
kubectl get pods --namespace cert-manager
helm install rancher rancher-latest/rancher \
--namespace rancher \
--set hostname=rancher.blabla.com
kubectl -n rancher rollout status deploy/rancher # wait
kubectl -n rancher get deploy rancher
The uninstall method from this page
./system-tools_linux-amd64 remove -c ~/.kube/config -n rancher
But it shows an error:
Are you sure you want to remove Rancher Management Plane in Namespace [rancher] [y/n]: y
INFO[0001] Removing Rancher management plane in namespace: [rancher]
INFO[0001] Getting connection configuration
INFO[0001] Removing Cattle deployment
INFO[0002] Removed Cattle deployment succuessfully
INFO[0002] Removing ClusterRoleBindings
INFO[0003] Successfully removed ClusterRoleBindings
INFO[0003] Removing ClusterRoles
INFO[0003] deleting cluster role [cluster-owner]..
INFO[0003] deleting cluster role [create-ns]..
INFO[0003] deleting cluster role [project-owner]..
INFO[0003] deleting cluster role [project-owner-promoted]..
INFO[0004] Successfully removed ClusterRoles
INFO[0004] Removing Cattle Annotations, Finalizers and Labels
INFO[0004] Checking API resource [bindings]
INFO[0004] Checking API resource [componentstatuses]
INFO[0004] Checking API resource [configmaps]
WARN[0005] Can't build dynamic client for [configmaps]: the server could not find the requested resource
INFO[0005] Checking API resource [endpoints]
WARN[0005] Can't build dynamic client for [endpoints]: the server could not find the requested resource
INFO[0005] Checking API resource [events]
WARN[0005] Can't build dynamic client for [events]: the server could not find the requested resource
INFO[0005] Checking API resource [limitranges]
WARN[0005] Can't build dynamic client for [limitranges]: the server could not find the requested resource
INFO[0005] Checking API resource [namespaces]
WARN[0005] Can't build dynamic client for [namespaces]: the server could not find the requested resource
INFO[0005] Checking API resource [namespaces/finalize]
INFO[0005] Checking API resource [namespaces/status]
INFO[0005] Checking API resource [nodes]
WARN[0006] Can't build dynamic client for [nodes]: the server could not find the requested resource
INFO[0006] Checking API resource [nodes/proxy]
INFO[0006] Checking API resource [nodes/status]
INFO[0006] Checking API resource [persistentvolumeclaims]
WARN[0006] Can't build dynamic client for [persistentvolumeclaims]: the server could not find the requested resource
INFO[0006] Checking API resource [persistentvolumeclaims/status]
INFO[0006] Checking API resource [persistentvolumes]
WARN[0006] Can't build dynamic client for [persistentvolumes]: the server could not find the requested resource
INFO[0006] Checking API resource [persistentvolumes/status]
INFO[0006] Checking API resource [pods]
WARN[0006] Can't build dynamic client for [pods]: the server could not find the requested resource
INFO[0006] Checking API resource [pods/attach]
INFO[0006] Checking API resource [pods/binding]
INFO[0006] Checking API resource [pods/eviction]
INFO[0006] Checking API resource [pods/exec]
INFO[0006] Checking API resource [pods/log]
INFO[0006] Checking API resource [pods/portforward]
INFO[0006] Checking API resource [pods/proxy]
INFO[0006] Checking API resource [pods/status]
INFO[0006] Checking API resource [podtemplates]
WARN[0006] Can't build dynamic client for [podtemplates]: the server could not find the requested resource
INFO[0006] Checking API resource [replicationcontrollers]
WARN[0007] Can't build dynamic client for [replicationcontrollers]: the server could not find the requested resource
INFO[0007] Checking API resource [replicationcontrollers/scale]
INFO[0007] Checking API resource [replicationcontrollers/status]
INFO[0007] Checking API resource [resourcequotas]
WARN[0007] Can't build dynamic client for [resourcequotas]: the server could not find the requested resource
INFO[0007] Checking API resource [resourcequotas/status]
INFO[0007] Checking API resource [secrets]
WARN[0007] Can't build dynamic client for [secrets]: the server could not find the requested resource
INFO[0007] Checking API resource [serviceaccounts]
WARN[0007] Can't build dynamic client for [serviceaccounts]: the server could not find the requested resource
INFO[0007] Checking API resource [serviceaccounts/token]
INFO[0007] Checking API resource [services]
WARN[0008] Can't build dynamic client for [services]: the server could not find the requested resource
INFO[0008] Checking API resource [services/proxy]
INFO[0008] Checking API resource [services/status]
INFO[0008] Checking API resource [apiservices]
WARN[0008] Can't build dynamic client for [apiservices]: the server could not find the requested resource
INFO[0008] Checking API resource [apiservices/status]
INFO[0008] Checking API resource [controllerrevisions]
WARN[0008] Can't build dynamic client for [controllerrevisions]: the server could not find the requested resource
INFO[0008] Checking API resource [daemonsets]
WARN[0009] Can't build dynamic client for [daemonsets]: the server could not find the requested resource
INFO[0009] Checking API resource [daemonsets/status]
INFO[0009] Checking API resource [deployments]
WARN[0009] Can't build dynamic client for [deployments]: the server could not find the requested resource
INFO[0009] Checking API resource [deployments/scale]
INFO[0009] Checking API resource [deployments/status]
INFO[0009] Checking API resource [replicasets]
WARN[0009] Can't build dynamic client for [replicasets]: the server could not find the requested resource
INFO[0009] Checking API resource [replicasets/scale]
INFO[0009] Checking API resource [replicasets/status]
INFO[0009] Checking API resource [statefulsets]
WARN[0009] Can't build dynamic client for [statefulsets]: the server could not find the requested resource
INFO[0009] Checking API resource [statefulsets/scale]
INFO[0009] Checking API resource [statefulsets/status]
INFO[0009] Checking API resource [events]
WARN[0010] Can't build dynamic client for [events]: the server could not find the requested resource
INFO[0010] Checking API resource [tokenreviews]
INFO[0010] Checking API resource [localsubjectaccessreviews]
INFO[0010] Checking API resource [selfsubjectaccessreviews]
INFO[0010] Checking API resource [selfsubjectrulesreviews]
INFO[0010] Checking API resource [subjectaccessreviews]
INFO[0010] Checking API resource [horizontalpodautoscalers]
WARN[0011] Can't build dynamic client for [horizontalpodautoscalers]: the server could not find the requested resource
INFO[0011] Checking API resource [horizontalpodautoscalers/status]
INFO[0011] Checking API resource [jobs]
WARN[0011] Can't build dynamic client for [jobs]: the server could not find the requested resource
INFO[0011] Checking API resource [jobs/status]
INFO[0011] Checking API resource [certificatesigningrequests]
WARN[0011] Can't build dynamic client for [certificatesigningrequests]: the server could not find the requested resource
INFO[0011] Checking API resource [certificatesigningrequests/approval]
INFO[0011] Checking API resource [certificatesigningrequests/status]
INFO[0012] Checking API resource [ingressclasses]
WARN[0012] Can't build dynamic client for [ingressclasses]: the server could not find the requested resource
INFO[0012] Checking API resource [ingresses]
WARN[0012] Can't build dynamic client for [ingresses]: the server could not find the requested resource
INFO[0012] Checking API resource [ingresses/status]
INFO[0012] Checking API resource [networkpolicies]
WARN[0012] Can't build dynamic client for [networkpolicies]: the server could not find the requested resource
INFO[0013] Checking API resource [ingresses]
WARN[0013] Can't build dynamic client for [ingresses]: the server could not find the requested resource
INFO[0013] Checking API resource [ingresses/status]
INFO[0013] Checking API resource [poddisruptionbudgets]
WARN[0013] Can't build dynamic client for [poddisruptionbudgets]: the server could not find the requested resource
INFO[0013] Checking API resource [poddisruptionbudgets/status]
INFO[0013] Checking API resource [podsecuritypolicies]
WARN[0013] Can't build dynamic client for [podsecuritypolicies]: the server could not find the requested resource
INFO[0014] Checking API resource [clusterrolebindings]
WARN[0014] Can't build dynamic client for [clusterrolebindings]: the server could not find the requested resource
INFO[0014] Checking API resource [clusterroles]
WARN[0014] Can't build dynamic client for [clusterroles]: the server could not find the requested resource
INFO[0014] Checking API resource [rolebindings]
WARN[0014] Can't build dynamic client for [rolebindings]: the server could not find the requested resource
INFO[0014] Checking API resource [roles]
WARN[0014] Can't build dynamic client for [roles]: the server could not find the requested resource
INFO[0015] Checking API resource [csidrivers]
WARN[0015] Can't build dynamic client for [csidrivers]: the server could not find the requested resource
INFO[0015] Checking API resource [csinodes]
WARN[0015] Can't build dynamic client for [csinodes]: the server could not find the requested resource
INFO[0015] Checking API resource [storageclasses]
WARN[0015] Can't build dynamic client for [storageclasses]: the server could not find the requested resource
INFO[0015] Checking API resource [volumeattachments]
WARN[0016] Can't build dynamic client for [volumeattachments]: the server could not find the requested resource
INFO[0016] Checking API resource [volumeattachments/status]
INFO[0016] Checking API resource [mutatingwebhookconfigurations]
WARN[0016] Can't build dynamic client for [mutatingwebhookconfigurations]: the server could not find the requested resource
INFO[0016] Checking API resource [validatingwebhookconfigurations]
WARN[0016] Can't build dynamic client for [validatingwebhookconfigurations]: the server could not find the requested resource
INFO[0016] Checking API resource [customresourcedefinitions]
WARN[0017] Can't build dynamic client for [customresourcedefinitions]: the server could not find the requested resource
INFO[0017] Checking API resource [customresourcedefinitions/status]
INFO[0017] Checking API resource [priorityclasses]
WARN[0017] Can't build dynamic client for [priorityclasses]: the server could not find the requested resource
INFO[0017] Checking API resource [leases]
WARN[0017] Can't build dynamic client for [leases]: the server could not find the requested resource
INFO[0018] Checking API resource [runtimeclasses]
WARN[0018] Can't build dynamic client for [runtimeclasses]: the server could not find the requested resource
INFO[0018] Checking API resource [endpointslices]
WARN[0018] Can't build dynamic client for [endpointslices]: the server could not find the requested resource
INFO[0018] Checking API resource [flowschemas]
WARN[0019] Can't build dynamic client for [flowschemas]: the server could not find the requested resource
INFO[0019] Checking API resource [flowschemas/status]
INFO[0019] Checking API resource [prioritylevelconfigurations]
WARN[0019] Can't build dynamic client for [prioritylevelconfigurations]: the server could not find the requested resource
INFO[0019] Checking API resource [prioritylevelconfigurations/status]
INFO[0019] Checking API resource [perconaxtradbclusterbackups]
WARN[0019] Can't build dynamic client for [perconaxtradbclusterbackups]: the server could not find the requested resource
INFO[0019] Checking API resource [perconaxtradbclusterbackups/status]
INFO[0019] Checking API resource [perconaxtradbclusterrestores]
WARN[0020] Can't build dynamic client for [perconaxtradbclusterrestores]: the server could not find the requested resource
INFO[0020] Checking API resource [perconaxtradbclusterrestores/status]
INFO[0020] Checking API resource [perconaxtradbclusters]
WARN[0020] Can't build dynamic client for [perconaxtradbclusters]: the server could not find the requested resource
INFO[0020] Checking API resource [perconaxtradbclusters/status]
INFO[0020] Checking API resource [challenges]
WARN[0020] Can't build dynamic client for [challenges]: the server could not find the requested resource
INFO[0020] Checking API resource [challenges/status]
INFO[0020] Checking API resource [orders]
WARN[0020] Can't build dynamic client for [orders]: the server could not find the requested resource
INFO[0020] Checking API resource [orders/status]
INFO[0021] Checking API resource [clusterrepos]
WARN[0021] Can't build dynamic client for [clusterrepos]: the server could not find the requested resource
INFO[0021] Checking API resource [clusterrepos/status]
INFO[0021] Checking API resource [apps]
WARN[0021] Can't build dynamic client for [apps]: the server could not find the requested resource
INFO[0021] Checking API resource [apps/status]
INFO[0021] Checking API resource [operations]
WARN[0021] Can't build dynamic client for [operations]: the server could not find the requested resource
INFO[0021] Checking API resource [operations/status]
INFO[0022] Checking API resource [clusterissuers]
WARN[0022] Can't build dynamic client for [clusterissuers]: the server could not find the requested resource
INFO[0022] Checking API resource [clusterissuers/status]
INFO[0022] Checking API resource [certificaterequests]
WARN[0022] Can't build dynamic client for [certificaterequests]: the server could not find the requested resource
INFO[0022] Checking API resource [certificaterequests/status]
INFO[0022] Checking API resource [certificates]
WARN[0022] Can't build dynamic client for [certificates]: the server could not find the requested resource
INFO[0022] Checking API resource [certificates/status]
INFO[0022] Checking API resource [issuers]
WARN[0022] Can't build dynamic client for [issuers]: the server could not find the requested resource
INFO[0022] Checking API resource [issuers/status]
INFO[0023] Checking API resource [gitjobs]
WARN[0023] Can't build dynamic client for [gitjobs]: the server could not find the requested resource
INFO[0023] Checking API resource [gitjobs/status]
INFO[0023] Checking API resource [prometheusrules]
WARN[0023] Can't build dynamic client for [prometheusrules]: the server could not find the requested resource
INFO[0023] Checking API resource [thanosrulers]
WARN[0024] Can't build dynamic client for [thanosrulers]: the server could not find the requested resource
INFO[0024] Checking API resource [alertmanagers]
WARN[0024] Can't build dynamic client for [alertmanagers]: the server could not find the requested resource
INFO[0024] Checking API resource [podmonitors]
WARN[0024] Can't build dynamic client for [podmonitors]: the server could not find the requested resource
INFO[0024] Checking API resource [probes]
WARN[0024] Can't build dynamic client for [probes]: the server could not find the requested resource
INFO[0024] Checking API resource [servicemonitors]
WARN[0024] Can't build dynamic client for [servicemonitors]: the server could not find the requested resource
INFO[0024] Checking API resource [prometheuses]
WARN[0025] Can't build dynamic client for [prometheuses]: the server could not find the requested resource
INFO[0025] Checking API resource [projects]
WARN[0025] Can't build dynamic client for [projects]: the server could not find the requested resource
INFO[0025] Checking API resource [projects/status]
INFO[0025] Checking API resource [roletemplates]
WARN[0025] Can't build dynamic client for [roletemplates]: the server could not find the requested resource
INFO[0025] Checking API resource [roletemplates/status]
INFO[0025] Checking API resource [clusters]
WARN[0025] Can't build dynamic client for [clusters]: the server could not find the requested resource
INFO[0025] Checking API resource [clusters/status]
INFO[0025] Checking API resource [roletemplatebindings]
WARN[0026] Can't build dynamic client for [roletemplatebindings]: the server could not find the requested resource
INFO[0026] Checking API resource [roletemplatebindings/status]
INFO[0026] Checking API resource [clusters]
WARN[0026] Can't build dynamic client for [clusters]: the server could not find the requested resource
INFO[0026] Checking API resource [clusters/status]
INFO[0026] Checking API resource [gitrepos]
WARN[0026] Can't build dynamic client for [gitrepos]: the server could not find the requested resource
INFO[0026] Checking API resource [gitrepos/status]
INFO[0026] Checking API resource [bundles]
WARN[0026] Can't build dynamic client for [bundles]: the server could not find the requested resource
INFO[0026] Checking API resource [bundles/status]
INFO[0026] Checking API resource [clusterregistrations]
WARN[0027] Can't build dynamic client for [clusterregistrations]: the server could not find the requested resource
INFO[0027] Checking API resource [clusterregistrations/status]
INFO[0027] Checking API resource [clusterregistrationtokens]
WARN[0027] Can't build dynamic client for [clusterregistrationtokens]: the server could not find the requested resource
INFO[0027] Checking API resource [clusterregistrationtokens/status]
INFO[0027] Checking API resource [bundledeployments]
WARN[0027] Can't build dynamic client for [bundledeployments]: the server could not find the requested resource
INFO[0027] Checking API resource [bundledeployments/status]
INFO[0027] Checking API resource [gitreporestrictions]
WARN[0027] Can't build dynamic client for [gitreporestrictions]: the server could not find the requested resource
INFO[0027] Checking API resource [gitreporestrictions/status]
INFO[0027] Checking API resource [contents]
WARN[0028] Can't build dynamic client for [contents]: the server could not find the requested resource
INFO[0028] Checking API resource [clustergroups]
WARN[0028] Can't build dynamic client for [clustergroups]: the server could not find the requested resource
INFO[0028] Checking API resource [clustergroups/status]
INFO[0028] Checking API resource [bundlenamespacemappings]
WARN[0028] Can't build dynamic client for [bundlenamespacemappings]: the server could not find the requested resource
INFO[0028] Checking API resource [bundlenamespacemappings/status]
INFO[0028] Checking API resource [clusters]
WARN[0028] Can't build dynamic client for [clusters]: the server could not find the requested resource
INFO[0028] Checking API resource [clusters/status]
INFO[0028] Checking API resource [roles]
WARN[0029] Can't build dynamic client for [roles]: the server could not find the requested resource
INFO[0029] Checking API resource [roles/status]
INFO[0029] Checking API resource [roles/scale]
INFO[0029] Checking API resource [replicasettemplates]
WARN[0029] Can't build dynamic client for [replicasettemplates]: the server could not find the requested resource
INFO[0029] Checking API resource [replicasettemplates/status]
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x30 pc=0x148dedc]
goroutine 1 [running]:
github.com/rancher/system-tools/vendor/github.com/urfave/cli.HandleAction.func1(0xc000f3da30)
/go/src/github.com/rancher/system-tools/vendor/github.com/urfave/cli/app.go:472 +0x278
panic(0x1681e40, 0x2adb0e0)
/usr/local/go/src/runtime/panic.go:513 +0x1b9
github.com/rancher/system-tools/remove.getGroupAPIResourceList(0xc000198140, 0x0, 0x0, 0x0, 0x0, 0xc000e47580, 0x17, 0xc000ea7ac0, 0x1, 0x1, ...)
/go/src/github.com/rancher/system-tools/remove/remove.go:425 +0x9c
github.com/rancher/system-tools/remove.removeCattleAnnotationsFinalizersLabels(0xc000198140, 0x0, 0x0)
/go/src/github.com/rancher/system-tools/remove/remove.go:476 +0x1b2
github.com/rancher/system-tools/remove.DoRemoveRancher.func4(0x0, 0x0)
/go/src/github.com/rancher/system-tools/remove/remove.go:93 +0x2a
github.com/rancher/system-tools/utils.RetryWithCount(0xc000f3d400, 0x3, 0x0, 0x0)
/go/src/github.com/rancher/system-tools/utils/utils.go:53 +0x61
github.com/rancher/system-tools/remove.DoRemoveRancher(0xc000198140, 0x0, 0x0)
/go/src/github.com/rancher/system-tools/remove/remove.go:92 +0x373
reflect.Value.call(0x15fa8e0, 0x1995388, 0x13, 0x18df3cc, 0x4, 0xc0007a59d0, 0x1, 0x1, 0xc00067c080, 0xc000af43b0, ...)
/usr/local/go/src/reflect/value.go:447 +0x449
reflect.Value.Call(0x15fa8e0, 0x1995388, 0x13, 0xc0007a59d0, 0x1, 0x1, 0x5, 0x4, 0xc000686b40)
/usr/local/go/src/reflect/value.go:308 +0xa4
github.com/rancher/system-tools/vendor/github.com/urfave/cli.HandleAction(0x15fa8e0, 0x1995388, 0xc000198140, 0x0, 0x0)
/go/src/github.com/rancher/system-tools/vendor/github.com/urfave/cli/app.go:481 +0x1fb
github.com/rancher/system-tools/vendor/github.com/urfave/cli.Command.Run(0x18e1d91, 0x6, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1911f67, 0x2a, 0x0, ...)
/go/src/github.com/rancher/system-tools/vendor/github.com/urfave/cli/command.go:186 +0x8f6
github.com/rancher/system-tools/vendor/github.com/urfave/cli.(*App).Run(0xc0003a6d80, 0xc0000381e0, 0x6, 0x6, 0x0, 0x0)
/go/src/github.com/rancher/system-tools/vendor/github.com/urfave/cli/app.go:235 +0x52e
main.main()
/go/src/github.com/rancher/system-tools/main.go:84 +0x5c3
How to uninstall it manually?
Solution 1:[1]
Remove the cattle-system namespace where rancher install all its components. kubectl delete ns cattle-system
Solution 2:[2]
system-tools remove --kubeconfig --namespace
I was able to delete the rancher deploy with this command :
system-tools remove --kubeconfig /etc/rancher/k3s/k3s.yaml --namespace cattle-system
Solution 3:[3]
As I understand it, uninstalling manually is an arduous task that will most likely lead to a broken cluster if in an RKE2 cluster. So, I'm providing the details to remove Rancher for that situation.
I used the 2.6 HA RKE2 Rancher docs to install Rancher and found a certificate issue that required me to remove Rancher from an RKE2 cluster. I am using Windows (PowerShell) and was ultimately able to remove Rancher. First I had to download the exe from the Rancher/system-tools repo on github. The instructions on how to use system-tools needed a slight mod for me to get the results needed. Also note that one of the steps is to rename the longer file name to system-tools.exe, so if you don't change it, you'll need to provide the name of that file in place of system-tools in the below command.
DID NOT WORK ./system-tools remove -c ~/.kube/config -n cattle-system
So I did a cd to the .kube directory and ran this...
DID WORK ./system-tools remove config -n cattle-system
config is the name of the file (kubeconfig) that holds your cluster details. Mine was literally config (no extension).
The below is from the README.MD on the current repo...
system-tools Rancher 2.0 operations tool kit.
Commands Remove Usage:
system-tools remove [command options] [arguments...] Options:
--kubeconfig value, -c value: kubeconfig absolute path [$KUBECONFIG] --namespace cattle-system, -n cattle-system: rancher 2.x deployment namespace. default is cattle-system (default: "cattle-system") --force: Skip the the interactive removal confirmation and remove the Rancher deployment right away. The system-tools remove command is used to delete a Rancher 2.x management plane deployment. It operates by applying the following steps:
Remove Rancher Deployment. Remove Rancher-Labeled ClusterRoles and ClusterRoleBindings. Remove Labels, Annotations and Finalizers from all resources on the management plane cluster. Remove Machines, Clusters, Projects and Users CRDs and corresponding namespaces. Remove all resources created under the management.cattle.io API group. Reamove all CRDs created by Rancher 2.x. Remove the Rancher deployment Namespace, default is cattle-system. Logs Usage:
system-tools logs [command options] [arguments...] Options:
--kubeconfig value, -c value: managed cluster kubeconfig [$KUBECONFIG] --output value, -o value: cluster logs tarball (default: "cluster-logs.tar") --node value, -n value: fetch logs for a single node The system-tools logs command is used to pull Kubernetes components' Docker container logs deployed by RKE on cluster nodes.
The command works by deploying a DaemonSet on the managed cluster, that uses the Rancher node-agent image to mount RKE logs directory and tar the logs on each node and stream them the host running system-tools. Once the the logs are pulled, the DaemonSet is removed automatically.
It's also possible to use the --node option to pull logs from a specific node.
Stats Usage:
system-tools stats [command options] [arguments...] Options:
--kubeconfig value, -c value: managed cluster kubeconfig [$KUBECONFIG] --node value, -n value: show stats for a single node --stats-command value, -s value: alternative command to run on the servers (default: "/usr/bin/sar -u -r -F 1 1") The system-tools stats command is used to pull real-time stats from Rancher-Managed Kubernetes cluster nodes. The default is to pull CPU, memory and disk usage stats.
The command works by deploying a DaemonSet on the managed cluster, that uses the Rancher node-agent to run pods used to execute the stats command on each node. Stats are displayed live every 5 seconds. The tool keeps running until the user interrupts its execution using ctrl+c which will trigger a cleanup command and remove the stats DaemonSet.
It's also possible to monitor a single node with the --node option or run another stats command using the --stats-command option.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Sachin Shaji |
| Solution 2 | marianc |
| Solution 3 | axsgitty |