Shulou(Shulou.com)06/03 Report--

This series of articles:

Chapter one: nine analysis will take you to easily complete the date introduction of K8s pod

Chapter 2: nine analysis takes you to easily complete the K8s pod time setting.

Catalogue

1 PodPreset introduction

2 PodPreset enabled

2.1 PodPreset confirmation

2.2 PodPreset enabled

3 PodPreset creation

4 PodPreset verification

1 PodPreset introduction

We learned in the previous section that the docker container will use UTC (International Standard time) by default, because we are CST (Beijing time), so the time in the container will be 8 hours later than Beijing time.

How to modify the container time in batches to keep it in sync with the Beijing time we use? It can be implemented using PodPreset.

PodPreset is a k8s API resource that presets (preset) information such as secrets, configmap, environment variables, volume mounts, etc. when creating a Pod. With PodPreset, instead of displaying the information we need to write for each Pod, we just execute PodPreset API and automatically inject that information into the specified Pod container.

For instructions on PodPreset, click to view.

2 PodPreset enabled

2.1 PodPreset confirmation

The resource type of PodPreset in K8S is settings.k8s.io/v1alpha1, which is not enabled by default. View commands:

Kubectl api-versions

Or:

Kubectl get podpreset

2.2 PodPreset enabled

Edit the / etc/kubernetes/manifests/kube-apiserver.yaml configuration file, add the runtime-config option to the startup parameters, and append PodPreset to the original enable-admission-plugins option.

-- runtime-config=settings.k8s.io/v1alpha1=true / / added

-- enable-admission-plugins=NodeRestriction,PodPreset / / append

It should be noted that:

First: if the cluster is multi-master, then each master needs to be modified.

Second: after modifying the kube-apiserver.yaml file, apiserver will restart automatically, so you need to wait some time.

3 PodPreset creation

Write the resource file pod-preset.yaml:

ApiVersion: settings.k8s.io/v1alpha1

Kind: PodPreset

Metadata:

Name: pod-env-preset

Namespace: default

Spec:

Selector:

MatchLabels:

App: nginx

VolumeMounts:

-mountPath: / etc/localtime

Name: localtime

Volumes:

-name: localtime

HostPath:

Path: / etc/localtime

Create a Podpreset resource:

Kubectl apply-f pod-preset.yaml

View Podpreset resources:

Kubectl get podpreset

4 PodPreset verification

Pay special attention to the scope of PodPreset is namespace. So when creating a pod resource, the namespace should be correct:

Write the resource file pod.yaml:

ApiVersion: v1

Kind: Pod

Metadata:

Name: nginx

Namespace: default

Labels:

App: nginx

Spec:

Containers:

-name: nginx

Image: nginx

Ports:

-containerPort: 80

Create a pod resource:

Kubectl apply-f pod.yaml

After the pod is created successfully, go to the pod container to view the time:

Kubectl exec-it nginx / bin/sh

Since then, pod preset time modification has been easily completed.

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