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Node.js应用程序无法使用Kubernetes连接到MongoDB Docker容器

[英]Node.js application fails to connect to MongoDB Docker container using Kubernetes

原文 2018-07-19 23:24:57 9 1 mongodb/ docker/ kubernetes

I am encountering an ENOTFOUND error within a multi-container Kubernetes pod. 我在多容器Kubernetes容器中遇到ENOTFOUND错误。 MongoDB is in one Docker container and appears to be fully operational, and a Node.js application is in another container (see its error below). MongoDB在一个Docker容器中，并且似乎可以完全运行，而Node.js应用程序在另一个容器中（请参见下面的错误）。

/opt/systran/apps-node/enterprise-server/node_modules/mongoose/node_modules/mongodb/lib/replset.js:365
          process.nextTick(function() { throw err; })
                                        ^
MongoError: failed to connect to server [mongodb:27017] on first connect [MongoError: getaddrinfo ENOTFOUND mongodb mongodb:27017]
    at Pool. (/opt/systran/apps-node/enterprise-server/node_modules/mongodb-core/lib/topologies/server.js:336:35)
    at emitOne (events.js:116:13)
    at Pool.emit (events.js:211:7)
    at Connection. (/opt/systran/apps-node/enterprise-server/node_modules/mongodb-core/lib/connection/pool.js:280:12)
    at Object.onceWrapper (events.js:317:30)
    at emitTwo (events.js:126:13)
    at Connection.emit (events.js:214:7)
    at Socket. (/opt/systran/apps-node/enterprise-server/node_modules/mongodb-core/lib/connection/connection.js:189:49)
    at Object.onceWrapper (events.js:315:30)
    at emitOne (events.js:116:13)
    at Socket.emit (events.js:211:7)
    at emitErrorNT (internal/streams/destroy.js:64:8)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)

In the application container I can do the following, so it seems to know that MongoDB is available on port 27017. 在应用程序容器中，我可以执行以下操作，因此似乎知道MongoDB在端口27017上可用。

curl "http://localhost:27017"
It looks like you are trying to access MongoDB over HTTP on the native driver port.

The application is intended to create databases in MongoDB, and populate collections. 该应用程序旨在在MongoDB中创建数据库，并填充集合。 This same set of Docker containers work fine with Docker using a docker-compose.yml file. 使用docker-compose.yml文件，这组相同的Docker容器可以与Docker正常工作。 The containers are part of a legacy application (there are other containers in the same pod), and I don't have much control over their content. 这些容器是旧版应用程序的一部分（在同一容器中有其他容器），我对其内容没有太多控制。

I have checked logs for the various containers. 我已经检查了各种容器的日志。 Have reviewed all stock pods with "kubectl get pods" and all are working fine. 用“ kubectl get pods”检查了所有库存豆荚，并且一切正常。 Using "flannel" for CNI, so use the following to initialize Kubernetes. 对CNI使用“法兰绒”，因此请使用以下内容初始化Kubernetes。

kubeadm init --pod-network-cidr=10.244.0.0/16

1 个解决方案

According to the error output, your NodeJS application tries to connect to MongoDB database via mongodb:27017 . 根据错误输出，您的NodeJS应用程序尝试通过mongodb:27017连接到MongoDB数据库。

As both NodeJS application and MongoDB database are containers of the same pod, NodeJS application should be connected to MongoDB database via localhost:27017 instead, because containers in a pod share storage/network resources. 由于NodeJS应用程序和MongoDB数据库都是同一Pod的容器，因此NodeJS应用程序应通过localhost:27017连接到MongoDB数据库，因为Pod中的容器共享存储/网络资源。

So, you need to change NodeJS application's configuration: set connection to MongoDB localhost:27017 instead of mongodb:27017 . 因此，您需要更改NodeJS应用程序的配置：将连接设置为MongoDB localhost:27017而不是mongodb:27017 。