How to define a readiness probe on a container for checking another containers health in the same pod?

huangapple
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英文:

How to define a readiness probe on a container for checking another containers health in the same pod?

问题

我在OpenShift中有一个包含Container A和Container B的部署对象。在这里的要求是，每当Container B退出时，Container A应该跟随，否则整个Pod应该被替换。

是否有办法实现这个要求？

这是我的YAML文件。

  1. apiVersion: apps/v1
  2. kind: Deployment
  3. metadata:
  4.   name: app-redis-bundle
  5.   labels:
  6.     app: app-redis-bundle
  7. spec:
  8.   replicas: 1
  9.   selector:
  10.     matchLabels:
  11.       app: app-redis-bundle
  12.   template:
  13.     metadata:
  14.       labels:
  15.         app: app-redis-bundle
  16.     spec:
  17.       containers:
  18.         - name: cache-store-2
  19.           image: redis
  20.           resources:
  21.             limits:
  22.               cpu: 500m
  23.               memory: 1500Mi
  24.             requests:
  25.               cpu: 250m
  26.               memory: 1Gi
  27.           ports:
  28.             - containerPort: 6379
  29.           livenessProbe:
  30.             tcpSocket:
  31.               port: 6379
  32.         
  33.         - name: app-server-2
  34.           image: 'app:latest'
  35.           resources:
  36.             limits:
  37.               cpu: '1'
  38.               memory: 1Gi
  39.             requests:
  40.               cpu: 500m
  41.               memory: 512Mi
  42.           ports:
  43.             - containerPort: 8443
  44.           livenessProbe:
  45.             tcpSocket:
  46.               port: 8443
  47.       imagePullSecrets:
  48.         - name: mysecret
英文:

I have a Deployment object with Container A and Container B in OpenShift.
The requirement here is that whenever container B exits, container A should follow or otherwise the entire pod should be replaced.

Is there any way to achieve this?

This is my YAML.

  1. apiVersion: apps/v1
  2. kind: Deployment
  3. metadata:
  4.   name: app-redis-bundle
  5.   labels:
  6.     app: app-redis-bundle
  7. spec:
  8.   replicas: 1
  9.   selector:
  10.     matchLabels:
  11.       app: app-redis-bundle
  12.   template:
  13.     metadata:
  14.       labels:
  15.         app: app-redis-bundle
  16.     spec:
  17.       containers:
  18.         - name: cache-store-2
  19.           image: redis
  20.           resources:
  21.             limits:
  22.               cpu: 500m
  23.               memory: 1500Mi
  24.             requests:
  25.               cpu: 250m
  26.               memory: 1Gi
  27.           ports:
  28.             - containerPort: 6379
  29.           livenessProbe:
  30.             tcpSocket:
  31.               port: 6379
  32.         
  33.         - name: app-server-2
  34.           image: 'app:latest'
  35.           resources:
  36.             limits:
  37.               cpu: '1'
  38.               memory: 1Gi
  39.             requests:
  40.               cpu: 500m
  41.               memory: 512Mi
  42.           ports:
  43.             - containerPort: 8443
  44.           livenessProbe:
  45.             tcpSocket:
  46.               port: 8443
  47.       imagePullSecrets:
  48.         - name: mysecret

答案1

得分: 1

感谢您的评论。

问题现已解决。

请允许我详细说明并解释解决方案。

问题描述

我需要在OpenShift中部署一个Pod，其中包含两个容器A和B，使得当容器A终止时，容器B也应自动终止。

最初，我的方法是从容器A中运行一个终止脚本来终止容器B。然而，这个方法没有起作用。

解决方案

使用一个活跃探针在容器B中发送从B到A的运行端口的TCP Socket连接就解决了问题，现在只要A退出，B就会立即终止。

任务完成。

以下是可用的YAML配置。

  1. apiVersion: v1
  2. kind: Pod
  3. metadata:
  4.   labels:
  5.     test: liveness
  6.   name: live
  7. spec:
  8.   restartPolicy: Never
  9.   containers:
  10.   - name: nginx
  11.     image: nginx:latest
  12.     args:
  13.     - /bin/sh
  14.     - -c
  15.     - touch /tmp/healthy; sleep 30; rm -f /tmp/healthy; sleep 600;
  16.     livenessProbe:
  17.       exec:
  18.         command:
  19.         - cat
  20.         - /tmp/healthy
  21.       initialDelaySeconds: 5
  22.       periodSeconds: 5
  24.   - name: liveness
  25.     image: registry.k8s.io/busybox
  26.     ports:
  27.     - containerPort: 80
  28.     livenessProbe:
  29.       tcpSocket:
  30.         port: 80
  31.       initialDelaySeconds: 5
  32.       periodSeconds: 5
英文:

Thanks for your comments.

The issue is resolved now.

Allow me to elaborate it and explain the solution.

Problem Statement

I was needed to deploy a Pod in OpenShift with 2 containers A and B in a manner such that whenever container A terminates, container B should automatically kill itself as well.

Initially, my approach was to run a termination script in container B from container A. However, this approach didn't help.

Solution

Using a liveness probe to send a TCP Socket connection from B to A on the running port did the magic and now B is terminating as soon as A exits.

Job done.

Below is the working yaml.

  1. apiVersion: v1
  2. kind: Pod
  3. metadata:
  4.   labels:
  5.     test: liveness
  6.   name: live
  7. spec:
  8.   restartPolicy: Never
  9.   containers:
  10.   - name: nginx
  11.     image: nginx:latest
  12.     args:
  13.     - /bin/sh
  14.     - -c
  15.     - touch /tmp/healthy; sleep 30; rm -f /tmp/healthy; sleep 600;
  16.     livenessProbe:
  17.       exec:
  18.         command:
  19.         - cat
  20.         - /tmp/healthy
  21.       initialDelaySeconds: 5
  22.       periodSeconds: 5
  24.   - name: liveness
  25.     image: registry.k8s.io/busybox
  26.     ports:
  27.     - containerPort: 80
  28.     livenessProbe:
  29.       tcpSocket:
  30.         port: 80
  31.       initialDelaySeconds: 5
  32.       periodSeconds: 5

答案2

得分: 0

both containers use the same ephemeral network, which means container A can communicate with container B on "localhost:port".

This multi-container pod is explained here in a clear way.

英文:

both containers use the same ephemeral network, which means container A can communicate with container B on "localhost:port".

This multi-container pod is explained here in a clear way.

huangapple
  • 本文由 发表于 2023年3月15日 19:30:04
  • 转载请务必保留本文链接：https://go.coder-hub.com/75744096.html
  • containers
  • kubernetes
  • livenessprobe
  • readinessprobe
  • yaml
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