Kubernetes - Revision history

T1t0 at 00:19, 16 November 2025

2025-11-16T00:19:22Z

@@ Line 1,162: / Line 1,162: @@
 kubectl exec $(kubectl get pod -l cnpg.io/cluster=cloudnative-pg-cluster,cnpg.io/instanceRole=primary -o name) -it -- psql -U postgres
 ...
 </pre>

T1t0 at 22:37, 5 October 2025

2025-10-05T22:37:12Z

← Older revision		Revision as of 22:37, 5 October 2025
Line 1,211:		Line 1,211:
	[https://medium.com/hackernoon/a-kubernetes-guide-for-docker-swarm-users-c14c8aa266cc A Kubernetes guide for Docker Swarm lovers]		[https://medium.com/hackernoon/a-kubernetes-guide-for-docker-swarm-users-c14c8aa266cc A Kubernetes guide for Docker Swarm lovers]

	~~[[Category:unix]]~~
	[[Category:linux]]		[[Category:linux]]
	[[Category:debian]]		[[Category:debian]]

T1t0 at 11:28, 5 October 2025

2025-10-05T11:28:58Z

← Older revision		Revision as of 11:28, 5 October 2025
Line 28:		Line 28:

	<pre>		<pre>
	apt-get -q -y install -y curl ethtool iproute2 socat conntrack		apt-get -q -y install curl ethtool iproute2 socat conntrack kmod
	apt-get -q -y clean		apt-get -q -y clean
	</pre>		</pre>
Line 41:		Line 41:
	# or ARCH="arm64"		# or ARCH="arm64"
	### install containerd		### install containerd
	VERSION="1.~~7.25~~"		VERSION="2.1.3"
	curl -fsSL "https://github.com/containerd/containerd/releases/download/v${VERSION}/containerd-${VERSION}-linux-${ARCH}.tar.gz" \| tar -C /usr/local/ -xz		curl -fsSL "https://github.com/containerd/containerd/releases/download/v${VERSION}/containerd-${VERSION}-linux-${ARCH}.tar.gz" \| tar -C /usr/local/ -xz
	### configure containerd to be started with systemd		### configure containerd to be started with systemd
	curl -fsSL -o /~~etc~~/systemd/system/containerd.service "https://raw.githubusercontent.com/containerd/containerd/main/containerd.service"		mkdir -p /usr/local/lib/systemd/system/
			curl -fsSL -o /usr/local/lib/systemd/system/containerd.service "https://raw.githubusercontent.com/containerd/containerd/main/containerd.service"
			systemctl daemon-reload
	systemctl enable containerd		systemctl enable containerd
	### install runc		### install runc
	VERSION="1.2.4"		VERSION="1.3.0"
	curl -fsSL -o /usr/local/sbin/runc "https://github.com/opencontainers/runc/releases/download/v${VERSION}/runc.${ARCH}"		curl -fsSL -o /usr/local/sbin/runc "https://github.com/opencontainers/runc/releases/download/v${VERSION}/runc.${ARCH}"
	chmod 0755 /usr/local/sbin/runc		chmod 0755 /usr/local/sbin/runc
	### install cni plugins		### install cni plugins
	VERSION="1.6.2"		VERSION="1.7.1"
	mkdir -p /opt/cni/bin		mkdir -p /opt/cni/bin
	curl -fsSL "https://github.com/containernetworking/plugins/releases/download/v${VERSION}/cni-plugins-linux-${ARCH}-v${VERSION}.tgz" \| tar -C /opt/cni/bin -xz		curl -fsSL "https://github.com/containernetworking/plugins/releases/download/v${VERSION}/cni-plugins-linux-${ARCH}-v${VERSION}.tgz" \| tar -C /opt/cni/bin -xz
	</pre>		</pre>

	~~Then, going back to https://kubernetes.io/docs/setup/production-environment/container-runtimes/#containerd-systemd to configure Containerd to use systemd as cgroup driver and start it~~		Get default config

	<pre>		<pre>
	mkdir -p /etc/containerd		mkdir -p /etc/containerd
	containerd config default > /etc/containerd/config.toml		containerd config default > /etc/containerd/config.toml
			</pre>

			Then, going back to https://kubernetes.io/docs/setup/production-environment/container-runtimes/#containerd-systemd to configure Containerd to use systemd as cgroup driver and start it

			<pre>
	sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml		sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
	~~systemctl daemon-reload~~
	systemctl start containerd		systemctl start containerd
	systemctl status -n 100 -o cat containerd		systemctl status -n 100 -o cat containerd
Line 80:		Line 86:
	cd /usr/local/bin		cd /usr/local/bin
	### install crictl		### install crictl
	CRICTL_VERSION="v1.32.0"		CRICTL_VERSION="v1.33.0"
	curl -fsSL "https://github.com/kubernetes-sigs/cri-tools/releases/download/${CRICTL_VERSION}/crictl-${CRICTL_VERSION}-linux-${ARCH}.tar.gz" \| tar -xz		curl -fsSL "https://github.com/kubernetes-sigs/cri-tools/releases/download/${CRICTL_VERSION}/crictl-${CRICTL_VERSION}-linux-${ARCH}.tar.gz" \| tar -xz
	chmod 0755 crictl		chmod 0755 crictl
	chown root:root crictl		chown root:root crictl
	### install kubeadm and kubelet		### install kubeadm and kubelet
	KUBE_VERSION="v1.32.0"		KUBE_VERSION="v1.33.2"
	curl -fsSL --remote-name-all "https://dl.k8s.io/release/${KUBE_VERSION}/bin/linux/${ARCH}/{kubeadm,kubelet}"		curl -fsSL --remote-name-all "https://dl.k8s.io/release/${KUBE_VERSION}/bin/linux/${ARCH}/{kubeadm,kubelet}"
	chmod 0755 {kubeadm,kubelet}		chmod 0755 {kubeadm,kubelet}
Line 91:		Line 97:
	### install kubernetes service and confs		### install kubernetes service and confs
	RELEASE_VERSION="v0.16.2"		RELEASE_VERSION="v0.16.2"
	curl -fsSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubelet/kubelet.service" \| sed "s:/usr/bin:/usr/local/bin:g" > /~~etc~~/systemd/system/kubelet.service		curl -fsSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubelet/kubelet.service" \| sed "s:/usr/bin:/usr/local/bin:g" > /usr/local/lib/systemd/system/kubelet.service
	mkdir -p /usr/lib/systemd/system/kubelet.service.d		mkdir -p /usr/local/lib/systemd/system/kubelet.service.d
	curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubeadm/10-kubeadm.conf" \| sed "s:/usr/bin:/usr/local/bin:g" > /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf		curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubeadm/10-kubeadm.conf" \| sed "s:/usr/bin:/usr/local/bin:g" > /usr/local/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
	### start kubelet in a crashloop waiting for our manual kubeadm init cluster		### start kubelet in a crashloop waiting for our manual kubeadm init cluster
			systemctl daemon-reload
	systemctl enable kubelet		systemctl enable kubelet
	systemctl start kubelet		systemctl start kubelet
	systemctl status -n 100 -o cat kubelet		systemctl status -n 100 -o cat kubelet
	</pre>		</pre>

			Note from the doc: "The kubelet is now restarting every few seconds, as it waits in a crashloop for kubeadm to tell it what to do."

	== Install Kubectl ==		== Install Kubectl ==
Line 112:		Line 121:
	cd /usr/local/bin		cd /usr/local/bin
	### install kubectl		### install kubectl
	KUBE_VERSION="v1.32.0"		KUBE_VERSION="v1.33.2"
	curl -fsSL --remote-name-all "https://dl.k8s.io/release/${KUBE_VERSION}/bin/linux/${ARCH}/kubectl"		curl -fsSL --remote-name-all "https://dl.k8s.io/release/${KUBE_VERSION}/bin/linux/${ARCH}/kubectl"
	chmod 0755 kubectl		chmod 0755 kubectl

T1t0: /* Install */

2025-01-14T00:23:19Z

Install

← Older revision		Revision as of 00:23, 14 January 2025
Line 44:		Line 44:
	curl -fsSL "https://github.com/containerd/containerd/releases/download/v${VERSION}/containerd-${VERSION}-linux-${ARCH}.tar.gz" \| tar -C /usr/local/ -xz		curl -fsSL "https://github.com/containerd/containerd/releases/download/v${VERSION}/containerd-${VERSION}-linux-${ARCH}.tar.gz" \| tar -C /usr/local/ -xz
	### configure containerd to be started with systemd		### configure containerd to be started with systemd
	curl -fsSL -o /~~usr/local/lib~~/systemd/system/containerd.service "https://raw.githubusercontent.com/containerd/containerd/main/containerd.service"		curl -fsSL -o /etc/systemd/system/containerd.service "https://raw.githubusercontent.com/containerd/containerd/main/containerd.service"
	systemctl enable containerd		systemctl enable containerd
	### install runc		### install runc
Line 91:		Line 91:
	### install kubernetes service and confs		### install kubernetes service and confs
	RELEASE_VERSION="v0.16.2"		RELEASE_VERSION="v0.16.2"
	curl -fsSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubelet/kubelet.service" \| sed "s:/usr/bin:/usr/local/bin:g" > /~~usr/lib~~/systemd/system/kubelet.service		curl -fsSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubelet/kubelet.service" \| sed "s:/usr/bin:/usr/local/bin:g" > /etc/systemd/system/kubelet.service
	mkdir -p /usr/lib/systemd/system/kubelet.service.d		mkdir -p /usr/lib/systemd/system/kubelet.service.d
	curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubeadm/10-kubeadm.conf" \| sed "s:/usr/bin:/usr/local/bin:g" > /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf		curl -sSL "https://raw.githubusercontent.com/kubernetes/release/${RELEASE_VERSION}/cmd/krel/templates/latest/kubeadm/10-kubeadm.conf" \| sed "s:/usr/bin:/usr/local/bin:g" > /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf

T1t0: /* Install */

2025-01-12T00:44:24Z

Install

← Older revision		Revision as of 00:44, 12 January 2025
Line 24:		Line 24:

	Then, we will install Containerd as our container runtime		Then, we will install Containerd as our container runtime

			=== Install base packages ===

			<pre>
			apt-get -q -y install -y curl ethtool iproute2 socat conntrack
			apt-get -q -y clean
			</pre>

	=== Install Containerd ===		=== Install Containerd ===

T1t0: /* Install */

2025-01-12T00:37:15Z

Install

Show changes

T1t0: /* Add postgres High Availability stateful app */

2024-04-02T23:45:34Z

Add postgres High Availability stateful app

Show changes

T1t0: /* Configure Cert-manager with letsencrypt */

2024-03-25T00:19:25Z

Configure Cert-manager with letsencrypt

← Older revision		Revision as of 00:19, 25 March 2024
Line 373:		Line 373:

	<pre>		<pre>
	curl -SsL https://github.com/cert-manager/cert-manager/releases/download/v1.12.4/cert-manager.yaml -o 00-cert-manager.yaml		curl -SsL https://github.com/cert-manager/cert-manager/releases/download/v1.14.4/cert-manager.yaml -o 00-cert-manager.yaml
	kubectl apply -f 00-cert-manager.yaml		kubectl apply -f 00-cert-manager.yaml
	</pre>		</pre>
Line 509:		Line 509:
	</pre>		</pre>

	* validate ~~staging~~ certificate		* validate production certificate

	<pre>		<pre>

T1t0: /* Notes */

2024-03-07T07:23:46Z

Notes

@@ Line 990: / Line 990: @@
 = Notes =
 * To see most of the resources:
@@ Line 1,013: / Line 1,015: @@
 <pre>
 kubectl apply does a three-way diff between the previous configuration, the provided input and the current configuration of the resource, in order to determine how to modify the resource.
 </pre>

T1t0: /* Add postgres High Availability stateful app */

2024-03-07T07:20:19Z

Add postgres High Availability stateful app

← Older revision		Revision as of 07:20, 7 March 2024
Line 976:		Line 976:
	...		...
	</pre>		</pre>

			* To solve problems with claimed but unused persistent volumes

			Kubegres will create claims on persistent volumes (i.e. persistentvolumeclaim a.k.a. pvc) to run pods as statefulset apps.

			When something goes wrong with the pod, it may decides to drop it and create a new one. If there is an available persistent volume for that, it will use the new one. But it cannot reuse the old claim (not sure if in some cases or in all cases) or the previous used pv, so if there is no pv available the satefulset app will be unable to create the pod. To unlock the situation, you need to remove the pvc, eventually clean the data if needed, and mark the volume as reusable as explained before.

	=== Using Cloudnative-pg ===		=== Using Cloudnative-pg ===