Install kind Using Rootless Podman on Oracle Linux
Introduction
kind is an open-source tool for running a locally hosted Kubernetes cluster using Podman containers as the cluster nodes. It provides a way for both developers and DevOps administrators to quickly create a Kubernetes cluster on a single machine without requiring the usual complicated and lengthy setup that would entail.
Objectives
In this lab, you'll learn how to:
- Install Podman
- Install
kubectl - Install kind
- Start kind using Rootless Podman
- Use kind to start a single-node Kubernetes cluster (control plane and worker on the same node)
Prerequisites
- A running instance of Oracle Linux 9
Verify the Lab Environment
Note: When using the free lab environment, see Oracle Linux Lab Basics for connection and other usage instructions.
Open a terminal and connect via ssh to the ol-node01 instance.
ssh oracle@<ip_address_of_ol_node01>
Install Podman
Install Podman.
sudo dnf install -y container-toolsConfirm the Podman version.
podman versionExample Output:
[oracle@ol-node01 ~]$ podman version Client: Podman Engine Version: 4.9.4-rhel API Version: 4.9.4-rhel Go Version: go1.21.9 (Red Hat 1.21.9-2.el9_4) Built: Fri May 3 09:46:34 2024 OS/Arch: linux/amd64
Confirm Podman Works
A quick test confirms that Podman works.
podman run quay.io/podman/helloExample Output:
[oracle@ol-node01 ~]$ podman run quay.io/podman/hello Trying to pull quay.io/podman/hello:latest... Getting image source signatures Copying blob d62784b1512e done Copying config dd579b6b41 done Writing manifest to image destination Storing signatures !... Hello Podman World ...! .--"--. / - - \ / (O) (O) \ ~~~| -=(,Y,)=- | .---. /` \ |~~ ~/ o o \~~~~.----. ~~ | =(X)= |~ / (O (O) \ ~~~~~~~ ~| =(Y_)=- | ~~~~ ~~~| U |~~ Project: https://github.com/containers/podman Website: https://podman.io Desktop: https://podman-desktop.io Documents: https://docs.podman.io YouTube: https://youtube.com/@Podman X/Twitter: @Podman_io Mastodon: @Podman_io@fosstodon.org
Install and Validate the Kubernetes Command Line Tool
kubectl is a command-line tool for interacting with Kubernetes clusters. kubectl installs on Linux, macOS, and MS Windows systems. This lab demonstrates installing on an Oracle Linux x86_64 system.
Note: The
kubectlversion must be within one minor version of the Kubernetes version deployed on the cluster. The steps provided here install the latest versions of both Kubernetes andkubectl.
Download the latest version of
kubectl.curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"Note: If a different version of
kubectlis needed to match an older Kubernetes version you are using in kind, replace the$(curl -L -s https://dl.k8s.io/release/stable.txt)section of the command shown above with the version-specific URL. For example,curl -LO https://dl.k8s.io/release/v1.27.4.(Optional) Validate the downloaded binary file.
Download the checksum file.
curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"Validate the
kubectldownload against the checksum file.echo "$(cat kubectl.sha256) kubectl" | sha256sum --checkExample Output:
[oracle@ol-node01 ~]$ echo "$(cat kubectl.sha256) kubectl" | sha256sum --check kubectl: OK
Install kubectl.
sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectlNote: If you do not have 'sudo' privileges, please use the steps shown below to install
kubectlinto your~/.local/bindirectory.chmod +x kubectl mkdir -p ~/.local/bin mv ./kubectl ~/.local/bin/kubectlThen add
~/.local/binto your$PATHVerify the
kubectlinstallation.kubectl version --client --output=yamlExample Output:
[oracle@ol-node01 ~]$ kubectl version --client --output=yaml clientVersion: buildDate: "2024-04-17T17:36:05Z" compiler: gc gitCommit: 7c48c2bd72b9bf5c44d21d7338cc7bea77d0ad2a gitTreeState: clean gitVersion: v1.30.0 goVersion: go1.22.2 major: "1" minor: "30" platform: linux/amd64 kustomizeVersion: v5.0.4-0.20230601165947-6ce0bf390ce3Configure Your Shell.
Using rootless Podman to run kind needs an environment variable to be declared. Add it to the BASH environment.
cat << EOF >> ~/.bashrc export KIND_EXPERIMENTAL_PROVIDER=podman EOFSource the
~/.bashrcfile to pick up the change.source ~/.bashrc
Ensure the Host is Running with Control Group v2
kind requires cgroup v2 to be configured in a specific manner to work. The following steps are necessary to accomplish this.
Check if cgroup v2 is already configred.
If
/sys/fs/cgroup/cgroup.controllersexists, the system is already running with cgroup v2.ls -al /sys/fs/cgroupOtherwise, enable cgroup v2 using
grubby.sudo grubby --update-kernel=ALL --args="systemd.unified_cgroup_hierarchy=1"Create the configuration file to enable delegation of the CPU controller.
sudo mkdir /etc/systemd/system/user@.service.dCreate a system-wide systemd user unit file to enable cgroup controller delegation.
cat << EOF | sudo tee /etc/systemd/system/user@.service.d/delegate.conf > /dev/null [Service] Delegate=yes EOFReload the systemd daemon.
sudo systemctl daemon-reloadReboot the instance for the changes to take effect.
sudo systemctl rebootNote: Wait a few minutes for the instance to restart.
Reconnect to the ol-nodel01 instance using ssh.
Enable Access to Iptables for Containers
Configure the iptables modules to load on system boot.
cat << EOF | sudo tee /etc/modules-load.d/iptables.conf > /dev/null ip6_tables ip6table_nat ip_tables iptable_nat EOFReload the kernel modules.
sudo systemctl restart systemd-modules-load.serviceVerify the kernel modules load.
lsmod|grep -E "^ip_tables|^iptable_filter|^iptable_nat|^ip6"
Download and Install kind
Install, and configure kind.
Download the latest version of kind.
[ $(uname -m) = x86_64 ] && curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.22.0/kind-linux-amd64Example Output:
[oracle@ol-node01 ~]$ [ $(uname -m) = x86_64 ] && curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.22.0/kind-linux-amd64 % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 97 100 97 0 0 1010 0 --:--:-- --:--:-- --:--:-- 1010 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0 100 6245k 100 6245k 0 0 7691k 0 --:--:-- --:--:-- --:--:-- 17.3MInstall kind.
sudo install -o root -g root -m 0755 kind /usr/local/bin/kindConfirm the kind version.
kind versionExample Output:
[oracle@ol-node01 ~]$ kind version kind v0.22.0 go1.20.13 linux/amd64
Confirm kind Works
Create a single node kind cluster.
kind create clusterExample Output:
NOTE: If using the free lab environment, the output will look similar to that shown below due to missing font packages on the Luna Desktop. It DOES NOT affect the functionality of kind in any way.
[oracle@ol-node01 ~]$ kind create cluster enabling experimental podman provider Creating cluster "kind" ... ��� Ensuring node image (kindest/node:v1.29.2) ������ ��� Preparing nodes ���� � ��� Writing configuration ������ ��� Starting control-plane ��������� ��� Installing CNI ������ ��� Installing StorageClass ������ Set kubectl context to "kind-kind" You can now use your cluster with: kubectl cluster-info --context kind-kind Have a nice day! ����If using your system, then the output should look similar to this:
[oracle@ol-node01 ~]$ kind create cluster enabling experimental podman provider Creating cluster "kind" ... ✓ Ensuring node image (kindest/node:v1.29.2) 🖼 ✓ Preparing nodes 📦 ✓ Writing configuration 📜 ✓ Starting control-plane 🕹️ ✓ Installing CNI 🔌 ✓ Installing StorageClass 💾 Set kubectl context to "kind-kind" You can now use your cluster with: kubectl cluster-info --context kind-kind Have a nice day! 😅Note: It is possible to use a custom name to create the kind cluster by supplying the name to use as shown in this example:
kind create cluster --name <name-of-cluster-to-create>.Confirm that
kubectlcan connect to the kind-based Kubernetes cluster.kubectl cluster-info --context kind-kindExample Output:
[oracle@ol-node01 ~]$ kubectl cluster-info --context kind-kind Kubernetes control plane is running at https://127.0.0.1:41691 CoreDNS is running at https://127.0.0.1:41691/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.You now have a working kind-based Kubernetes cluster.
The following 'Optional' sections show how to look inside the deployed containers to confirm a full Kubernetes implementation exists and how to create additional single-node kind-based Kubernetes clusters.
If you don't require the 'Optional' sections, please click the "Next" button until you reach the final section ('Delete the kind Clusters').
(Optional) Verify the Kubernetes Environment
Run a few commands to confirm the deployment of a fully functional Kubernetes cluster.
Use kind to check for the details of any running kind clusters.
kind get clustersExample Output:
[oracle@ol-node01 ~]$ kind get clusters enabling experimental podman provider kindConfirmation the cluster is running.
Note: Because Podman is running the kind executable, many commands will include a reference to using the 'experimental podman provider', like this:
enabling experimental podman provider.Check what Podman containers are running.
podman ps -aExample Output:
[oracle@ol-node01 ~]$ podman ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 7b27757cb244 quay.io/podman/hello:latest /usr/local/bin/po... About an hour ago Exited (0) About an hour ago inspiring_allen fb2bb3f1e6d9 docker.io/kindest/node@sha256:3966ac761ae0136263ffdb6cfd4db23ef8a83cba8a463690e98317add2c9ba72 17 minutes ago Up 17 minutes 127.0.0.1:41691->6443/tcp kind-control-planeNote: If more nodes exist in the kind cluster then a separate container will be listed for each 'node' of the kind cluster.
Confirm
kubectlknows about the newly creted cluster.Notice in the previous output that the 'PORTS' heading shows that network traffic on the local machine is being redirected from Port number 41691 to Port number 6443 inside the container, as shown here:
127.0.0.1:41691->6443/tcp. Before proceeding, let's check thatkubectlknows about the newly created cluster:grep server ~/.kube/configExample Output:
[oracle@ol-node01 ~]$ grep server ~/.kube/config server: https://127.0.0.1:41691Note: The actual Port number is dynamically assigned each time a kind cluster starts.
Take a quick look at the kind cluster using the
kubectl get nodescommand.kubectl get nodesExample Output:
[oracle@ol-node01 ~]$ kubectl get nodes NAME STATUS ROLES AGE VERSION kind-control-plane Ready control-plane 81s v1.29.2Confirm that a fully functional Kubernetes node was started.
kubectl get pods -AExample Output:
[oracle@ol-node01 ~]$ kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system coredns-5d78c9869d-9xjd5 1/1 Running 0 53s kube-system coredns-5d78c9869d-bmpgs 1/1 Running 0 53s kube-system etcd-kind-control-plane 1/1 Running 0 69s kube-system kindnet-vtxz7 1/1 Running 0 54s kube-system kube-apiserver-kind-control-plane 1/1 Running 0 69s kube-system kube-controller-manager-kind-control-plane 1/1 Running 0 69s kube-system kube-proxy-dq4t7 1/1 Running 0 54s kube-system kube-scheduler-kind-control-plane 1/1 Running 0 69s local-path-storage local-path-provisioner-6bc4bddd6b-z8z55 1/1 Running 0 53sConfirm that containerd (and not Podman) is running the kind cluster.
kubectl get nodes -o wideExample Output:
[oracle@ol-node01 ~]$ kubectl get nodes -o wide NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME kind-control-plane Ready control-plane 45m v1.29.2 10.89.0.3 <none> Debian GNU/Linux 11 (bullseye) 5.15.0-205.149.5.1.el9uek.x86_64 containerd://1.7.13Get a more in-depth look at the kind cluster.
kubectl get all -A | moreExample Output:
[oracle@ol-node01 ~]$ kubectl get all -A | more NAMESPACE NAME READY STATUS RESTARTS AGE kube-system pod/coredns-5d78c9869d-5b5ft 1/1 Running 0 18m kube-system pod/coredns-5d78c9869d-h2psz 1/1 Running 0 18m kube-system pod/etcd-kind-control-plane 1/1 Running 0 18m kube-system pod/kindnet-b6x9g 1/1 Running 0 18m kube-system pod/kube-apiserver-kind-control-plane 1/1 Running 0 18m kube-system pod/kube-controller-manager-kind-control-plane 1/1 Running 0 18m kube-system pod/kube-proxy-lpjpj 1/1 Running 0 18m kube-system pod/kube-scheduler-kind-control-plane 1/1 Running 0 18m local-path-storage pod/local-path-provisioner-6bc4bddd6b-hjs7m 1/1 Running 0 18m NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE default service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 18m kube-system service/kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 18m NAMESPACE NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE kube-system daemonset.apps/kindnet 1 1 1 1 1 kubernetes.io/os=linux 18m kube-system daemonset.apps/kube-proxy 1 1 1 1 1 kubernetes.io/os=linux 18m NAMESPACE NAME READY UP-TO-DATE AVAILABLE AGE kube-system deployment.apps/coredns 2/2 2 2 18m local-path-storage deployment.apps/local-path-provisioner 1/1 1 1 18m NAMESPACE NAME DESIRED CURRENT READY AGE kube-system replicaset.apps/coredns-5d78c9869d 2 2 2 18m local-path-storage replicaset.apps/local-path-provisioner-6bc4bddd6b 1 1 1 18m
(Optional) Check if Kubernetes is Running Inside the Container
The curious user may still be uncertain whether kind has deployed a full-featured Kubernetes cluster inside a container. The following steps outline how to confirm this.
Connect to the container's BASH shell.
podman exec -it kind-control-plane bashExample Output:
[oracle@ol-node01 ~]$ podman exec -it kind-control-plane bash root@kind-control-plane:/#crtictl is a command-line interface to inspect and debug container runtimes on a Kubernetes node. Use
crictlto confirm that all the expected Kubernetes services are present inside the kind container.crictl psExample Output:
root@kind-control-plane:/# crictl ps CONTAINER IMAGE CREATED STATE NAME ATTEMPT POD ID POD c76a6f0931550 ce18e076e9d4b 25 minutes ago Running local-path-provisioner 0 4b540b5b2f209 local-path-provisioner-6bc4bddd6b-z8z55 7e87927b14a75 ead0a4a53df89 25 minutes ago Running coredns 0 4f418c623d824 coredns-5d78c9869d-9xjd5 e7d5f3489f084 ead0a4a53df89 25 minutes ago Running coredns 0 7c737a7820ccc coredns-5d78c9869d-bmpgs 4f4357edf61c1 b0b1fa0f58c6e 25 minutes ago Running kindnet-cni 0 9be3ac0e411f8 kindnet-vtxz7 b785e2d63fb8e 9d5429f6d7697 25 minutes ago Running kube-proxy 0 fde29e49f009b kube-proxy-dq4t7 4d90a3a20fc04 205a4d549b94d 25 minutes ago Running kube-scheduler 0 ded2754976cd9 kube-scheduler-kind-control-plane bed955e049597 9f8f3a9f3e8a9 25 minutes ago Running kube-controller-manager 0 423ad427221b3 kube-controller-manager-kind-control-plane 5335909a407cb c604ff157f0cf 25 minutes ago Running kube-apiserver 0 51fb09697ae67 kube-apiserver-kind-control-plane 051d8db7eac77 86b6af7dd652c 25 minutes ago Running etcd 0 b9e063633caf6 etcd-kind-control-planeAll the expected Kubernetes file structure also exists, confirming Kubernetes is present.
ls /etc/kubernetes ls /etc/kubernetes/manifestsExample Output:
root@kind-control-plane:/# ls /etc/kubernetes admin.conf controller-manager.conf kubelet.conf manifests pki scheduler.conf etcd.yaml kube-apiserver.yaml kube-controller-manager.yaml kube-scheduler.yamlExit out of the container.
exit
(Optional) Create Another Single-Node kind Cluster
As indicated earlier, creating multiple kind clusters is possible concurrently. The following section shows how to achieve this.
Create another kind cluster.
Note that it is necessary to use the
--nameparameter this time because a default cluster using the default (kind-kind) name is present.kind create cluster --name newclusterExample Output:
[oracle@ol-node01 ~]$ kind create cluster --name newcluster enabling experimental podman provider Creating cluster "newcluster" ... ✓ Ensuring node image (kindest/node:v1.29.2) 🖼 ✓ Preparing nodes 📦 ✓ Writing configuration 📜 ✓ Starting control-plane 🕹️ ✓ Installing CNI 🔌 ✓ Installing StorageClass 💾 Set kubectl context to "kind-newcluster" You can now use your cluster with: kubectl cluster-info --context kind-newcluster Thanks for using kind! 😊NOTE: This output demonstrates the result if your environment contains the additional emoji font packages. The free lab environment's Luna Desktop does not include these and will show the non-descript blocks.
Confirm a new cluster has started.
Notice that two clusters should be listed -
kindandnewcluster.kind get clustersExample Output:
[oracle@ol-node01 ~]$ kind get clusters enabling experimental podman provider kind newclusterCheck how many containers exist using Podman.
podman psExample Output:
[oracle@ol-node01 ~]$ podman ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 83707b3b7b4c docker.io/kindest/node@sha256:3966ac761ae0136263ffdb6cfd4db23ef8a83cba8a463690e98317add2c9ba72 2 minutes ago Up 2 minutes 127.0.0.1:35735->6443/tcp kind-control-plane fa262f08de76 docker.io/kindest/node@sha256:3966ac761ae0136263ffdb6cfd4db23ef8a83cba8a463690e98317add2c9ba72 9 minutes ago Up 9 minutes 127.0.0.1:41691->6443/tcp newcluster-control-planeCheck how many Kubernetes clusters are in the
.kube/configfile.grep server ~/.kube/configExample Output:
[oracle@ol-node01 ~]$ grep server ~/.kube/config server: https://127.0.0.1:35735 server: https://127.0.0.1:41691
(Optional) Connect to Both Clusters Using the Kubernetes Command Line Tool.
Confirm that
kubectlshows both clusters.kubectl get nodesExample Output:
[oracle@ol-node01 ~]$ kubectl get nodes NAME STATUS ROLES AGE VERSION newcluster-control-plane Ready control-plane 27m v1.29.2Is something amiss? No, this is expected behavior. If more than one cluster is present, use the
--contextflag to indicate which cluster to connect to.kubectl get nodes --context kind-kindand
kubectl get nodes --context kind-newcluster
(Optional) Change the Default Cluster Context
Changing the default cluster context to one of the other cluster contexts is possible.
Confirm which cluster is the current default.
kubectl config get-contextsExample Output:
[oracle@ol-node01 ~]$ kubectl config get-contexts CURRENT NAME CLUSTER AUTHINFO NAMESPACE kind-kind kind-kind kind-kind * kind-newcluster kind-newcluster kind-newclusterThe asterisk (
*) indicates the current default context.Switch to the default context of
kind-kind.kubectl config use-context kind-kindExample Output:
[oracle@ol-node01 ~]$ kubectl config use-context kind-kind Switched to context "kind-kind".Confirm the default context now points to the
kind-kindcluster.kubectl config get-contextsExample Output:
[oracle@ol-node01 ~]$ kubectl config get-contexts CURRENT NAME CLUSTER AUTHINFO NAMESPACE * kind-kind kind-kind kind-kind kind-newcluster kind-newcluster kind-newcluster
Delete the kind Cluster.
Deleting a cluster is as simple as creating it.
Delete the default cluster.
kind delete clusterExample Output:
[oracle@ol-node01 ~]$ kind delete cluster enabling experimental podman provider Deleting cluster "kind" ... Deleted nodes: ["kind-control-plane"](Optional) Delete the second cluster.
Deleting the second cluster requires using the
--nameoption.kind delete cluster --name newclusterConfirm there are no kind clusters running.
kind get clustersExample Output:
[oracle@ol-node01 ~]$ kind get clusters enabling experimental podman provider No kind clusters found.
Summary
That completes our demonstration of how to install and run rootless kind on Podman. However, kind has many more features that go beyond the scope of this lab, such as these:
- Use different Kubernetes versions
- Define multiple Control and Worker nodes
- Setup an Ingress Controller
- Define a Metallb load balancer
- Use IPv4 (standard), IPv6 or dual stack clusters
- Work with local or private registries (registries requiring authentication)
- Work with an audit policy
Locate more details in the upstream kind documentation .
In the meantime, many thanks for taking the time to try this lab.