Lab #404: dbcluster state schema is missing DBClusterMembers (writer/reader, instance class)

The @swamp/aws/rds/dbcluster model's persisted state — populated by get / sync via the CloudControl AWS::RDS::DBCluster shape — does not include DBClusterMembers. After sync, the model cannot answer foundational questions about an Aurora cluster:

Which member is currently the writer?
What instance class is each member running?
Which AZ does each member live in?

CloudControl/CFN omits this information by design, but the RDS native DescribeDBClustersCommand returns it. For any workflow operating on live Aurora clusters (failover audits, instance-class migrations, AZ rebalancing), this gap forces consumers to bypass the data model and call AWS directly.

Implementation scope:

Augment get / sync to call DescribeDBClustersCommand (in addition to or in place of the CloudControl read), and persist member info into the state resource.
Schema change: add DBClusterMembers (with DBInstanceIdentifier, IsClusterWriter, DBClusterParameterGroupStatus, PromotionTier) to StateSchema. Optionally also enrich each entry with DBInstanceClass and AvailabilityZone by joining against DescribeDBInstances.
Additive, non-breaking — declare an upgrades entry for the new version.

Related: the list/discover gap is filed separately. Both share a fix path (direct @aws-sdk/client-rds usage), so they could land together.

Upstream repository: https://github.com/systeminit/swamp-extensions

Environment

Extension: @swamp/aws/rds@2026.05.06.1
swamp: 20260520.150010.0-sha.47868db6
OS: darwin (aarch64)
Deno: 2.7.14+19bd3d8
Shell: /bin/zsh

extension push: issue-verdict review is indistinguishable from missing/stale

Document model-method data-mutation surface (dataRepository.delete, findAllForModelSince, queryData)

@swamp/aws/cloudformation: expose StackSet instances, drift, and operations (Cloud Control cannot)

extension push: adversarial-review report hash is platform-dependent (macOS vs Linux), so committed reviews never match a cross-OS runner

model search --json returns a bare model object instead of {query, results} when exactly one model matches

model delete --json output shape doesn't match the documented {deleted, modelId, modelName, artifactsDeleted}

Extension API: allow export const extension to add resource specs, or document that it cannot

Add a way to list registered report definitions (report search only lists results)

workflow validate: method args with a Zod .default() are treated as required

Inconsistent resource-field accessor: data get returns content, data query and CEL use attributes

extension quality scorer mis-detects quoted phrases in comments as bare imports

Support CI-friendly adversarial review artifacts for extension push

extension push --dry-run --json reports local helper imports as bogus model entries

Extension source: direct-content export scan only reads first 64 KiB, silently drops exports beyond it

Managed skills ship with dangling reference-doc links

Add a list/discover method to dbcluster for enumerating clusters in a region

workflow-scope report's dataRepository.getContent returns null for data written in the same workflow run

dbcluster state schema is missing DBClusterMembers (writer/reader, instance class)

workflow direct-execution inputs.* persist as globalArguments on auto-definitions and freeze on first run

Workflow validation should resolve modelType for direct-execution steps

bucket-policy StateSchema.PolicyDocument declared z.string() but CloudControl returns it as a parsed object

bucket-policy GlobalArgsSchema requires Bucket and PolicyDocument, blocking workflow-YAML direct execution of get

Report execute throws are advisory: workflow marked succeeded, exit 0, AND report output is discarded

dataRepository.getContent rejects string type in production but docs and testing helper demonstrate strings

Relationships

#404 dbcluster state schema is missing DBClusterMembers (writer/reader, instance class)

Environment

Shipped