Question: How to represent array properties in parameter store?

[rmpestano]

Type: Bug

Component:
"Parameter Store"

Describe the bug
I need to represent list properties in parameter store, is it possible?

The main issue is that list indexes are represented by square brackets in Spring which are not supported as parameter names in ssm API, here's the pattern: a-zA-Z0-9_.-

Sample
Here's a sample spring config I want to represent on ssm:

config.users:
  - name: 'user1'
    password: 'pass1'
  - name: 'user2'
    password: 'pass2'

in parameter store I'd need the following parameters:

/config/app/config.users[0].name
/config/app/config.users[0].password
/config/app/config.users[1].name
/config/app/config.users[1].password

But I cannot create them because of the brackets.

Note that the env var representation would work as it uses _ for the array index.

[rmpestano]

Hi again,

We fixed this in our project by representing array indexes with _INDEX_. The example on the description of this issue would be represented as:

/config/app/config.users_0_.name
/config/app/config.users_0_.password
/config/app/config.users_1_.name
/config/app/config.users_1_.password

Not sure that would work as a general solution without breaking existing applications.

If someone else needs this now, in our project we've created a property source that just gets the parameters resolved by AwsParamStorePropertySource (they'll have the underscore array index notation) and transform them into the system properties array notation (with brackets):

public class ArraySupportParamStorePropertySource implements PropertySourceLocator {

    private final Map<String, Object> configProperties;

    public ArraySupportParamStorePropertySource(final AwsParamStorePropertySource awsParamStorePropertySource) {
        var parameterStoreParams = Arrays.stream(awsParamStorePropertySource.getPropertyNames()).toList();
        configProperties = parameterStoreParams.stream()
                .filter(param -> param.startsWith("my-config"))
                .map(param -> Map.entry(param.replaceAll("_(\\d)_", "[$1]"), awsParamStorePropertySource.getProperty(param)))
                .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
    }

    @Override
    public PropertySource<?> locate(Environment environment) {
        return new MapPropertySource("my-config", configProperties);
    }
}

[maciejwalkowiak]

Thanks @rmpestano! @MatejNedic is looking how to tackle this issue on the Spring Cloud AWS side. Perhaps we can come up together with a PR?

[rmpestano]

Hey @maciejwalkowiak, I've just opened a draft PR (#248), maybe we can use it as a starting point.

Cheers!