Docker 容器无法使用容器名称访问另一个容器

Question

I have 2 Docker containers running in the same network and I want 1 of them to call another via spring Webclient. I'm sure they all are in the same network -> docker network inspect <network_ID> proves this. AFAIK I can ping one container from another to check if they can talk to each other by docker exec -ti attachment-loader-prim ping attachment-loader-sec If I run this - I see responses from attachment-loader-sec like 64 bytes from 172.21.0.5: seq=0 ttl=64 time=0.220 ms , which means they can communicate. When I send Postman request to attachment-loader-prim by its exposed port localhost:8085 , I expect that after some business logic it calls for attachment-loader-sec via Webclient, but on that step I get a 500 error with such a message:

"finishConnect(..) failed: Connection refused: attachment-loader-sec/172.21.0.5:80; nested exception is io.netty.channel.AbstractChannel$AnnotatedConnectException: finishConnect(..) failed: Connection refused: attachment-loader-sec/172.21.0.5:80"

Both attachment-loader-prim and attachment-loader-sec can be accessed separately via postman and both send a response, no problem. This is my docker-compose:

    version: '3'
services:
  attachment-loader-prim:
    container_name: attachment-loader-prim
    build:
      context: ""
    restart: always
    image: attachment-loader:latest
    environment:
      SERVER_PORT: 8085
    networks:
      - loader_network
    expose:
      - 8085
    ports:
      - 8005:8005
      - 8085:8085

  attachment-loader-sec:
    container_name: attachment-loader-sec
    build:
      context: ""
    restart: always
    image: attachment-loader:latest
    environment:
      SERVER_PORT: 8086
    networks:
      - loader_network
    expose:
      - 8086
    ports:
      - 8006:8005
      - 8086:8086

networks:
  loader_network:
    driver: bridge

And this is a Webclient which makes a call:

    class RemoteServiceCaller(private val fetcherWebClientBuilder: WebClient.Builder) {

suspend fun getAttachmentsFromRemote(id: String, params: List<Param>, username: String): Result? {

    val client = fetcherWebClientBuilder.build()

    val awaitExchange = client.post()
            .uri("/{id}/attachment", id)
            .contentType(MediaType.APPLICATION_JSON)
            .bodyValue(params)
            .header(usernameHeader, username)
            .accept(MediaType.APPLICATION_OCTET_STREAM)
            .awaitExchange {
                if (it.statusCode().is2xxSuccessful) {
                    handleSucessCode(it)
                } else it.createExceptionAndAwait().run {
                    LOG.error(this.responseBodyAsString, this)
                    throw ProcessingException(this)
                }
            }

    return awaitExchange
}

private suspend fun handleSucessCode(response: ClientResponse) {
// some not important logic
}
}

PS BasicUri for Webclient defined as Config Bean like http://attachment-loader-sec/list

All my investigations brought me to such problems as:

• Calling container using localhost instead of container name
• Containers are not in the same network.

All that seems not relevant for me.

Any ideas will be really appreciated.

Answer 1

The problem was in calling a service without its port. The url became now http://attachment-loader-sec:8086/list and it is correct now. In my case I get 404, which means that my url path is not quite correct, but that is outside of current question