Default section with region required in .aws/config

I use some profiles with a ProfileCredentialsProvider to do the SDK operations and my config file has no [default] section.

Expected Behavior

The region information should be used from the given profile.

Current Behavior

The SDK throws the error:

software.amazon.awssdk.core.exception.SdkClientException: Unable to load region from any of the providers in the chain software.amazon.awssdk.regions.providers.DefaultAwsRegionProviderChain@11d045b4: [software.amazon.awssdk.regions.providers.SystemSettingsRegionProvider@17e9bc9e: Unable to load region from system settings. Region must be specified either via environment variable (AWS_REGION) or  system property (aws.region)., software.amazon.awssdk.regions.providers.AwsProfileRegionProvider@9301672: No region provided in profile: default, software.amazon.awssdk.regions.providers.InstanceProfileRegionProvider@163042ea: Unable to contact EC2 metadata service.]

	at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:97)
	at software.amazon.awssdk.regions.providers.AwsRegionProviderChain.getRegion(AwsRegionProviderChain.java:70)
	at software.amazon.awssdk.regions.providers.LazyAwsRegionProvider.getRegion(LazyAwsRegionProvider.java:45)
	at software.amazon.awssdk.awscore.client.builder.AwsDefaultClientBuilder.regionFromDefaultProvider(AwsDefaultClientBuilder.java:178)
	at software.amazon.awssdk.awscore.client.builder.AwsDefaultClientBuilder.resolveRegion(AwsDefaultClientBuilder.java:167)
	at software.amazon.awssdk.awscore.client.builder.AwsDefaultClientBuilder.lambda$mergeChildDefaults$0(AwsDefaultClientBuilder.java:111)
	at software.amazon.awssdk.utils.builder.SdkBuilder.applyMutation(SdkBuilder.java:61)
	at software.amazon.awssdk.core.client.config.SdkClientConfiguration.merge(SdkClientConfiguration.java:66)
	at software.amazon.awssdk.awscore.client.builder.AwsDefaultClientBuilder.mergeChildDefaults(AwsDefaultClientBuilder.java:111)
	at software.amazon.awssdk.core.client.builder.SdkDefaultClientBuilder.syncClientConfiguration(SdkDefaultClientBuilder.java:143)
	at software.amazon.awssdk.services.ec2.DefaultEc2ClientBuilder.buildClient(DefaultEc2ClientBuilder.java:27)
	at software.amazon.awssdk.services.ec2.DefaultEc2ClientBuilder.buildClient(DefaultEc2ClientBuilder.java:22)
	at software.amazon.awssdk.core.client.builder.SdkDefaultClientBuilder.build(SdkDefaultClientBuilder.java:119)
	at de.weltraumschaf.aws.DefaultAwsClientFactory.createEc2Client(DefaultAwsClientFactory.java:52)
	at de.weltraumschaf.FooTest.createVirtualPrivateCloud(FooTest.java:61)
	at de.porsche.zerog.servicebroker.broker.FooTest.foo(FooTest.java:51)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

Steps to Reproduce (for bugs)

Remove the [default] section from the files in ~/.aws and only add the region in the particular profiles.

Your Environment

• AWS Java SDK version used: 2.9.20
• JDK version used: JDK 1.8.0_131
• Operating System and version: macOS 10.14.6

[Weltraumschaf]

Hm, ok… Maybe I should look into Azure or GCP instead of AWS 😉

[millems]

You’re configuring the client to use the profile file for credentials, not region. In effect this is what you’re doing:

S3Client client =
    S3Client.builder()
            .credentialsProvider(ProfileCredentialsProvider.builder().profileName("snafu").build())
            .region(null) // use default region resolution logic
            .build();

It’s debatable whether that’s a “good reason” but it’s the reason. The AWS CLI does not have a way to configure credential providers and region providers separately, so that’s not a great example of the Java SDK behaving different than other tools.

If you want behavior equivalent to the AWS CLI, you’ll need to use the AWS_PROFILE environment variable or the aws.profile system property:

System.setProperty("aws.profile", "snafu");
S3Client client = S3Client.create();

It’s not ideal, but if you want equivalent behavior, that’s the least amount of code to do it.