Kubernetes 中的 Redis 不与节点连接

Question

我正在尝试学习DevOps，但在使用带有redis和node.js应用程序的Kubernetes时遇到了问题

我的node.js应用程序连接到redis，代码如下：

const redis = require('redis');
const client = redis.createClient(process.env.REDIS_URL);
module.exports =  client

我的带有deployment和service:的redis.yaml文件

---
apiVersion: apps/v1  # API version
kind: Deployment
metadata:
name: redis-master # Unique name for the deployment
labels:
app: redis       # Labels to be applied to this deployment
spec:
selector:
matchLabels:     # This deployment applies to the Pods matching these labels
app: redis
role: master
tier: backend
replicas: 1        # Run a single pod in the deployment
template:          # Template for the pods that will be created by this deployment
metadata:
labels:        # Labels to be applied to the Pods in this deployment
app: redis
role: master
tier: backend
spec:            # Spec for the container which will be run inside the Pod.
containers:
- name: master
image: redis
resources:
requests:
cpu: 100m
memory: 100Mi
ports:
- containerPort: 6379
---        
apiVersion: v1
kind: Service        # Type of Kubernetes resource
metadata:
name: redis-master # Name of the Kubernetes resource
labels:            # Labels that will be applied to this resource
app: redis
role: master
tier: backend
spec:
ports:
- port: 6379       # Map incoming connections on port 6379 to the target port 6379 of the Pod
targetPort: 6379
selector:          # Map any Pod with the specified labels to this service
app: redis
role: master
tier: backend

我的带有deployment和service:的app.yaml文件

---
apiVersion: apps/v1
kind: Deployment                 # Type of Kubernetes resource
metadata:
name: go-redis-app             # Unique name of the Kubernetes resource
spec:
replicas: 3                    # Number of pods to run at any given time
selector:
matchLabels:
app: go-redis-app          # This deployment applies to any Pods matching the specified label
template:                      # This deployment will create a set of pods using the configurations in this template
metadata:
labels:                    # The labels that will be applied to all of the pods in this deployment
app: go-redis-app 
spec:
containers:
- name: go-redis-app
image: alsoares59/devops-project:latest
imagePullPolicy: IfNotPresent
resources:
requests:
cpu: 100m
memory: 100Mi
ports:
- containerPort: 8080  # Should match the port number that the Go application listens on    
env:                     # Environment variables passed to the container
- name: REDIS_URL
value: redis-master
- name: PORT
value: "3000"
---
apiVersion: v1
kind: Service                    # Type of kubernetes resource
metadata:
name: go-redis-app-service     # Unique name of the resource
spec:
type: NodePort                 # Expose the Pods by opening a port on each Node and proxying it to the service.
ports:                         # Take incoming HTTP requests on port 9090 and forward them to the targetPort of 8080
- name: http
port: 9090
targetPort: 8080
selector:
app: go-redis-app            # Map any pod with label `app=go-redis-app` to this service

由于某种原因，在创建这些部署和服务时，我的node应用程序会崩溃，说它无法连接到redis。

[vagrant@centos-minikube k8s]$ kubectl logs go-redis-app-6b687c7bd6-6npt7
> express-redis@1.0.0 start /
> node src/server.js
redis server should be at redis-master
Server listening on port 3000
events.js:292
throw er; // Unhandled 'error' event
^
Error: connect ENOENT redis-master
at PipeConnectWrap.afterConnect [as oncomplete] (net.js:1146:16)
Emitted 'error' event on RedisClient instance at:
at RedisClient.on_error (/node_modules/redis/index.js:341:14)
at Socket.<anonymous> (/node_modules/redis/index.js:222:14)
at Socket.emit (events.js:315:20)
at emitErrorNT (internal/streams/destroy.js:106:8)
at emitErrorCloseNT (internal/streams/destroy.js:74:3)
at processTicksAndRejections (internal/process/task_queues.js:80:21) {
errno: -2,
code: 'ENOENT',
syscall: 'connect',
address: 'redis-master'
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! express-redis@1.0.0 start: `node src/server.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the express-redis@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR!     /root/.npm/_logs/2020-12-23T13_39_56_529Z-debug.log

我错过了什么？我知道Kubernetes应该将redis-master翻译成redis的pod IP地址，但我不知道他是否做得很好。

Answer 1

我自己找到的。我不得不将redis-client.js更改为：

const redis = require('redis');
console.log("redis server should be at "+process.env.REDIS_URL)
const client = redis.createClient({
host: process.env.REDIS_URL,
port: process.env.REDIS_PORT
});
module.exports =  client