Multi Container Docker应用程序-容器之间的连接被拒绝

Question

因此，我有一个多容器应用程序，它的前端和后端API都位于API网关后面。目前，当通过各自的命令(Java spring应用程序和Angular前端)独立启动时，所有应用程序都可以正常工作。但是，当我通过docker-compose up启动应用程序时，没有一个应用程序可以相互通信(连接被拒绝)。

Gateway只是一个基本的spring-cloud-gateway入门应用程序，它将请求路由到正确的应用程序。这是使用以下代码配置的：

    @Bean
    public RouteLocator routeLocator(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("api", route -> route.path("/api/**").uri("http://localhost:5001"))
                .route("front-end", route -> route.path("/**").uri("http://localhost:4200"))
                .build();
    }

错误消息

向http://localhost:5000/api/categories发送HTTP GET请求后，网关应用程序中会产生此错误消息。

api-gateway_1      | 2021-01-11 00:05:14.514 ERROR 1 --- [or-http-epoll-5] a.w.r.e.AbstractErrorWebExceptionHandler : [d29e1cbf-1]  500 Server Error for HTTP GET "/api/categories"
api-gateway_1      | 
api-gateway_1      | io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: localhost/127.0.0.1:5001
api-gateway_1      |    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
api-gateway_1      | Error has been observed at the following site(s):
api-gateway_1      |    |_ checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
api-gateway_1      |    |_ checkpoint ⇢ HTTP GET "/api/categories" [ExceptionHandlingWebHandler]
api-gateway_1      | Stack trace:
api-gateway_1      | Caused by: java.net.ConnectException: finishConnect(..) failed: Connection refused
api-gateway_1      |    at io.netty.channel.unix.Errors.throwConnectException(Errors.java:124) ~[netty-transport-native-unix-common-4.1.55.Final.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.channel.unix.Socket.finishConnect(Socket.java:251) ~[netty-transport-native-unix-common-4.1.55.Final.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe.doFinishConnect(AbstractEpollChannel.java:673) ~[netty-transport-native-epoll-4.1.55.Final-linux-x86_64.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe.finishConnect(AbstractEpollChannel.java:650) ~[netty-transport-native-epoll-4.1.55.Final-linux-x86_64.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe.epollOutReady(AbstractEpollChannel.java:530) ~[netty-transport-native-epoll-4.1.55.Final-linux-x86_64.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:470) ~[netty-transport-native-epoll-4.1.55.Final-linux-x86_64.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378) ~[netty-transport-native-epoll-4.1.55.Final-linux-x86_64.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989) ~[netty-common-4.1.55.Final.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.55.Final.jar!/:4.1.55.Final]
api-gateway_1      |    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.55.Final.jar!/:4.1.55.Final]
api-gateway_1      |    at java.base/java.lang.Thread.run(Unknown Source) ~[na:na]

尝试的步骤/更多信息

我曾尝试定义我自己的网络，但这并没有改变任何事情，所以我将容器保留在运行docker-compose up时创建的默认网络上。

我可以通过cURL或邮递员单独点击每个应用程序，我可以通过浏览器访问前端。

Docker-Compose.yml

version: "3"

services:
  api:
    build: ./api
    ports:
      - "5001:5001"
  gateway:
    build: ./gateway
    ports:
      - "5000:5000"
  frontend:
    build: ./frontend
    ports:
      - "4200:80"

Dockerfiles

网关

FROM openjdk:11 as build

COPY . .

RUN ./gradlew build --parallel

FROM openjdk:11-jre-slim as runtime

COPY --from=build /build/libs/gateway-0.0.1-SNAPSHOT.jar /usr/app/

WORKDIR /usr/app

ENTRYPOINT ["java", "-jar", "gateway-0.0.1-SNAPSHOT.jar"]

API接口

FROM openjdk:11 as build

COPY . .

RUN ./gradlew build --parallel

FROM openjdk:11-jre-slim as runtime

COPY --from=build /build/libs/api-0.0.1-SNAPSHOT.jar /usr/app/

WORKDIR /usr/app

ENTRYPOINT ["java", "-jar", "api-0.0.1-SNAPSHOT.jar"]

前端

FROM node:12.7-alpine AS build

WORKDIR usr/src/app

COPY package.json package-lock.json ./

RUN npm install

COPY . .

RUN npm run build

FROM nginx:1.17.1-alpine
COPY nginx.conf /etc/nginx/nginx.conf
COPY --from=build /usr/src/app/dist/awards-frontend /usr/share/nginx/html

Answer 1

感谢@DavidMaze让我注意到这一点。

看起来我有点傻。我的应用程序正在向localhost发送网络请求。当它们都在容器之外运行时，这种方法工作得很好。当在容器中时，它们需要向其他容器的名称发送请求。例如：

app_1在端口8080上运行app_2在端口5000上运行

在docker外部运行时，app_1可通过http://localhost:5000向app_2发送网络请求。这在容器内不起作用，因为容器中的localhost:5000上没有运行任何东西。相反，它需要引用另一个容器，例如：http://app_2:5000。