JHipster application in docker container cannot be accessed on host network, cannot communicate with other containers on non-host network

Question

I am trying to deploy my JHipster microservices and registry in docker containers on my OS X development machine.

I deploy the registry using more or less the default docker-compose configuration JHipster provides out of the box:

version: '2'
services:
    jhipster-registry:
        image: jhipster/jhipster-registry:v3.1.0
        volumes:
            - ./central-server-config:/central-config
        # When run with the "dev" Spring profile, the JHipster Registry will
        # read the config from the local filesystem (central-server-config directory)
        # When run with the "prod" Spring profile, it will read the configuration from a Git repository
        # See https://jhipster.github.io/microservices-architecture/#registry_app_configuration
        environment:
            - SPRING_PROFILES_ACTIVE=dev,native
            - SECURITY_USER_PASSWORD=admin
            - SPRING_CLOUD_CONFIG_SERVER_NATIVE_SEARCH_LOCATIONS=file:./central-config/localhost-config/
            # - GIT_URI=https://github.com/jhipster/jhipster-registry/
            # - GIT_SEARCH_PATHS=central-config
        ports:
            - 8761:8761

When I deploy my microservices using docker run, however, one of two things happens:

If I publish the port I want to make the microservice available on using -p 8080:8080 so I can access it through the browser, I can reach it but the microservice cannot find the registry.

Could not locate PropertySource: I/O error on GET request for "http://jhipster-registry:8761/config/clientaggregator/dev,twilio": Connection refused (Connection refused); nested exception is java.net.ConnectException: Connection refused (Connection refused)

Meanwhile, I can view the pages the registry serves fine.

I can fix this by adding "--network=host" when starting the microservice. However, when I do that this apparently overrides the native-to-host port mapping and the microservice cannot be reached from the browser.

What's more bizarre is that about a week ago I was using the exact same configuration, which worked fine.

If I run my application outside of a docker container, it connects to the registry fine. If I create a different container, or connect to the microservice container and access the configuration url via curl, I get a response.

Answer 1

Your app is trying to locate the registry using the name jhipster-registry as a host name. To be able to do that, you need to have your registry and app added to a docker network.

First create the network using:

docker network create my-network

Update the compose file by giving the container a name and adding it to the network create:

version: '2'
services:
    jhipster-registry:
        image: jhipster/jhipster-registry:v3.1.0
        volumes:
            - ./central-server-config:/central-config
        # When run with the "dev" Spring profile, the JHipster Registry will
        # read the config from the local filesystem (central-server-config directory)
        # When run with the "prod" Spring profile, it will read the configuration from a Git repository
        # See https://jhipster.github.io/microservices-architecture/#registry_app_configuration
        environment:
            - SPRING_PROFILES_ACTIVE=dev,native
            - SECURITY_USER_PASSWORD=admin
            - SPRING_CLOUD_CONFIG_SERVER_NATIVE_SEARCH_LOCATIONS=file:./central-config/localhost-config/
            # - GIT_URI=https://github.com/jhipster/jhipster-registry/
            # - GIT_SEARCH_PATHS=central-config
        ports:
            - 8761:8761
        networks:
            - my-network
        container_name: jhipster-registry


networks:
  my-network:
    external: true

When running your application specify the network:

docker run --network=my-network ...

Now your application can communicate with the registry using jhipster-registry as a hostname.