Testing This Module

From the original documentation for Net::Amazon::S3...

Testing S3 is a tricky thing. Amazon wants to charge you a bit of money each time you use their service. And yes, testing counts as using. Because of this, the application's test suite by default, skips anything approaching a real test.

I'm not so sure exactly how expensive creating a bucket and then reading and writing a few bytes from S3 really is nowadays. In any event, by default, the tests that actually create buckets and objects will not be executed unless you set the environment variable AMAZON_S3_EXPENSIVE_TESTS to some value. Testing can be controlled with additional environment variables described below.

| Variable | Description | | -------- | ----------- | | AMAZON_S3_EXPENSIVE_TESTS | Doesn't matter what you set it to. Just has to be set | | AWS_ACCESS_KEY_ID | Your AWS access key | | AWS_ACCESS_KEY_SECRET | Your AWS sekkr1t passkey. Be forewarned that setting this environment variable on a shared system might leak that information to another user. Be careful. | | AWS_SESSION_TOKEN | Optional session token. | | AMAZONS3_HOST | Defaults to s3.amazonaws.com. Set this for example if you want to test the module against an API compatible service like minio. | | AMAZON_S3_SKIP_ACL_TESTS | Doesn't matter what you set it to. Just has to be set if you want to skip ACLs tests. | | AMAZON_S3_SKIP_REGION_CONSTRAINT_TEST | Doesn't matter what you set it to. Just has to be set if you want to skip region constraint test. | | AMAZON_S3_MINIO | Doesn't matter what you set it to. Just has to be set if you want to skip tests that would fail on minio. | | AMAZON_S3_LOCALSTACK | Doesn't matter what you set it to. Just has to be set if you want to skip tests that would fail on minio. | | AMAZON_S3_REGIONS | Comma delimited list of regions to test |

CAUTION

In order to test ACLs, the test will create a public bucket and then make the bucket private. The test will perform the same kind of tests on objects. The test will also delete the bucket and the objects as well, however, stuff happens and you may be left with a public bucket or object should these tests fail.

Check your account to make sure the buckets and objects have been deleted. The bucket name will be have a prefix of net-amazon-s3-test- and a suffix of your AWS_ACCESS_KEY_ID.

Regional Constraints

One of the original unit tests for this module attempted to create a bucket in the EU region to ostensibly test regional constraints and DNS based bucket names.

The test would create a bucket in the default region, delete the bucket, then attempt to create a bucket with the same name in a different region. Today, this will fail consistently with a 409 error (Operation Aborted). This is due to the fact that you cannot immediately reclaim a bucket name after deletion as it may takes some time to free that bucket name in all regions.

Bucket restrictions and limitations

To test regional constraints then, the current test will change the name of the bucket if it encounters a 409 error while creating the bucket. The test will then proceed to read the ACLs to determine if the constraint was successful. By default, the tests will only create a bucket in the default region (but it will check that the constraint is in place). If you want to test creation of buckets in alternate regions in addition to testing in the default region, set the environment variable AMAZON_S3_REGIONS to one or more comma separated regions.

cd src/main/perl
make test AMAZON_S3_EXPENSIVE_TESTS=1 AMAZON_S3_REGIONS='eu-west-1'

Credentials for Testing

You should set the environment variables AWS_ACCESS_KEY_ID and AWS_ACCESS_SECRET_KEY to your AWS credential values that have the ability to create and write to buckets.

If you set environment variable AMAZON_S3_CREDENTIAL to any value, the tests will use the Amazon::Credentials module to look for valid credentials in your environment, your credentials files or the instance role if you are running on an EC2.

Using S3 Mocking Services

If you want to test some parts of this module but don't want to spend a few pennies (or don't have access to AWS credentials) you can try one of the S3 mocking services. The two of the most popular services seem to be:

Both of these implement a subset of the S3 API. Note that Some tests will fail on both services (as of the writing of this document). To make it through the tests, try setting one or more of the environment variables above which will selectively skip some test.

If you are using a mocking service, you might find it useful to set the environment variable AWS_EC2_METADATA_DISABLED to a true value.

export AWS_EC2_METADATA_DISABLED=true

This will prevent the AWS CLI from looking for metadata when you are not actually running on an EC2 instance or container. Without this variable set, the CLI attempts to access the metadata service at http://169.254.169.254/latest/meta-data/ until it eventually times out.

Testing with LocalStack

LocalStack seems to be the easiest to work with and supports a number of AWS APIs besides S3. It does not implement the full suite of APIs however. In particular, LocalStack does not enforce ACLs. Accordingly, those tests are skipped if the environment variable AMAZON_S3_LOCALSTACK is set to any value.

A docker-compose.yml file is included now in the project.

version: "3.8"

services:
  localstack:
    container_name: "${LOCALSTACK_DOCKER_NAME-localstack_main}"
    image: localstack/localstack
    hostname: s3
    networks:
      default:
        aliases:
          - s3.localhost.localstack.cloud
          - net-amazon-s3-test-test.localhost.localstack.cloud
    ports:
      - "127.0.0.1:4510-4530:4510-4530"
      - "127.0.0.1:4566:4566"
      - "127.0.0.1:4571:4571"
    environment:
      - SERVICES=s3,ssm,secretsmanager,kms,sqs,ec2,events,sts,logs
      - DEBUG=${DEBUG-}
      - DATA_DIR=${DATA_DIR-}
      - LAMBDA_EXECUTOR=${LAMBDA_EXECUTOR-}
      - HOST_TMP_FOLDER=${TMPDIR:-/tmp/}localstack
      - DOCKER_HOST=unix:///var/run/docker.sock
    volumes:
      -  "${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack"
      - "/var/run/docker.sock:/var/run/docker.sock"

When testing with LocalStack you'll need to set some environment variables to get through (the majority) of the tests.

Environment Variable | Value | Description -------------------- | ----- | ----------- AMAZON_EXPENSIVE_TESTS | 1 | enables testing of S3 API AMAZONS3_HOST | localhost:4566 AMAZON_S3_LOCALSTACK | any | skips some tests that will fail on LocalStack AWS_ACCESS_KEY_ID | test | AWS access key for LocalStack AWS_ACCESS_KEY_SECRET | test | AWS secret access key for LocalStack

In order to test domain name buckets, you will need to spoof a domain name for your bucket by setting the name of the bucket in your /etc/hosts file.

127.0.0.1 localhost net-amazon-s3-test-test.s3.localhost.localstack.cloud

To run tests using LocalStack...

 AMAZON_S3_EXPENSIVE_TESTS=1 \
 AMAZON_S3_HOST=s3.localhost.localstack.cloud:4566 \
 AMAZON_S3_LOCALSTACK=1 \
 AWS_ACCESS_KEY_ID=test \
 AWS_ACCESS_SECRET_KEY=test  \
 AMAZON_S3_DOMAIN_BUCKET_NAMES=1 make test