Caused by: java.net.UnknownHostException: alc-vbox-testarchiveservice.minio with Minio and docker-compose

Question

We are using Minio for local testing of S3 AND we have created docker-compose file with Minio and our app dependency are as follows:

Docker-Compose File:

version: "2.1"

services:
  minio:
    image: minio/minio
    container_name: minio
    ports:
      - 9001:9001
    volumes:
      - minio_storage:/data
    environment:
      MINIO_ACCESS_KEY: minio
      MINIO_SECRET_KEY: minio123
      MINIO_REGION: us-east-1
    command: server /data --console-address ":9001"
    mem_limit: 512m

  populate-minio-data:
    container_name: "minio-data"
    image: minio/mc
    volumes:
      - ./hello.txt:/tmp/hello.txt
    entrypoint: >
      /bin/sh -c "
      /usr/bin/mc config host rm local;
      /usr/bin/mc config host add --quiet --api s3v4 local http://minio:9001 minio minio123;
      /usr/bin/mc mb --quiet local/somebucketname1/;
      /usr/bin/mc policy set public local/somebucketname1;
      /usr/bin/mc cp /tmp/hello.txt local/somebucketname1/hello.txt;
      "
    depends_on:
      - minio


  archive-api-app:
    image: openjdk:11
    container_name: "archive-api-app"
    ports:
      - 8091:6001
    volumes:
      - /home/apcuser/dev/projects/ea-archive-service-v2/projects/application/archive-api:/app
    command: [ 'java', '-jar', '/app/build/libs/archive-api-1.0.0.jar' ]
    env_file:
      - ./vars/default.env

volumes:
  minio_storage:

And In java code, I have configured MINIO URL as S3 Endpoint as follows:

@Bean
    public AmazonS3 getS3Client() {
        return AmazonS3ClientBuilder.standard()
                .withClientConfiguration(new ClientConfiguration().withMaxConnections(maxConnections)
                        .withConnectionTimeout(connectionTimeout).withMaxErrorRetry(maxRetry))
            .withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration("http://minio:9001", "us-east-1"))
                .build();
    }

Once, I run docker-compose file,I am able to see minio-ui in my local Linux machine as follows:

But when I am hitting API request from postman to my archive-api-app, App throwing below error:

    archive-api            |    at java.base/java.lang.Thread.run(Thread.java:829)
archive-api            | Caused by: java.net.UnknownHostException: alc-vbox-testarchiveservice.minio
archive-api            |    at java.base/java.net.InetAddress$CachedAddresses.get(InetAddress.java:797)
archive-api            |    at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1519)
archive-api            |    at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1378)
archive-api            |    at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1306)
archive-api            |    at com.amazonaws.SystemDefaultDnsResolver.resolve(SystemDefaultDnsResolver.java:27)
archive-api            |    at com.amazonaws.http.DelegatingDnsResolver.resolve(DelegatingDnsResolver.java:38)
archive-api            |    at org.apache.http.impl.conn.DefaultHttpClientConnectionOperator.connect(DefaultHttpClientConnectionOperator.java:112)
archive-api            |    at org.apache.http.impl.conn.PoolingHttpClientConnectionManager.connect(PoolingHttpClientConnectionManager.java:376)
archive-api            |    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
archive-api            |    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
archive-api            |    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
archive-api            |    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
archive-api            |    at com.amazonaws.http.conn.ClientConnectionManagerFactory$Handler.invoke(ClientConnectionManagerFactory.java:76)
archive-api            |    at com.amazonaws.http.conn.$Proxy97.connect(Unknown Source)
archive-api            |    at org.apache.http.impl.execchain.MainClientExec.establishRoute(MainClientExec.java:393)
archive-api            |    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:236)
archive-api            |    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
archive-api            |    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
archive-api            |    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
archive-api            |    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
archive-api            |    at com.amazonaws.http.apache.client.impl.SdkHttpClient.execute(SdkHttpClient.java:72)
archive-api            |    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1346)
archive-api            |    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1157)
archive-api            |    ... 77 more

Does anyone know Why I am getting UnknownHostException? My doubt is since, I configured Minio-url(http://minio:9001) in the code where I am creating S3 configs, then why my code is trying to connect to alc-vbox-testarchiveservice.minio host? (My bucket name is: alc-vbox-testarchiveservice)

score 1 · Accepted Answer · answered Apr 16 '23 at 18:27

There are a couple of approaches to solving this problem. Many people are following this approach where they are adding host.docker.internal as an extra host. I haven't taken this approach due to some limitations of my application.

I have taken the following approach:

We just need to set withPathStyleAccessEnabled(true) flag while creating MINIO bean, with this S3 URL won't be created like . instead it will create with .com/

and while creating MINIO bean set the URL as http://minio:9000 instead http://minio:9001 since 9000 is the API port through which data can be uploaded.

    @Bean
public AmazonS3 getS3Client() {
    return AmazonS3ClientBuilder.standard()
        .withClientConfiguration(new ClientConfiguration().withMaxConnections(maxConnections)
            .withConnectionTimeout(connectionTimeout).withMaxErrorRetry(maxRetry))
        .withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration("http://minio:9000", "us-east-1"))
        .withPathStyleAccessEnabled(true)
        .build();
}

Caused by: java.net.UnknownHostException: alc-vbox-testarchiveservice.minio with Minio and docker-compose

1 Answers1