RDS - Import existing DatabaseInstance from ARN

[Dzhuneyt]

Currently the AWS CDK only allows creating a DB instance. It would be great to be able to import and reuse existing RDS instances.

Use Case

Creating a CI pipeline that automatically provisions QA "sandboxes" of the app, that are all connected and reuse the same DB instance.

Because of this use case.

Proposed Solution

DatabaseInstance.fromArn();

---

This is a 🚀 Feature Request

[jogold]

You should be able to use fromDatabaseInstanceAttributes for this:

aws-cdk/packages/@aws-cdk/aws-rds/lib/instance.ts

Line 88 in b14172d

public static fromDatabaseInstanceAttributes(scope: Construct, id: string, attrs: DatabaseInstanceAttributes): IDatabaseInstance {

[nija-at]

Hi @Dzhuneyt -

Let us know if the API that @jogold has referred to above does not satisfy your use case.

Marking this issue as closing soon.

[mariusingjer]

It would be great with an example of how this is supposed to work. The suggestion from the author is to import based on arn, the method referred to is requiring instance identifier, port, security group ++. Whats the suggested solution here? To export everything required by the fromInstanceAttributes?

[romor]

It would be great with an example of how this is supposed to work.

Not sure whether this is correct, but I would try it like this:

const db = rds.DatabaseInstance.fromDatabaseInstanceAttributes(this, "myDb", {
      instanceIdentifier: "db-name",
      instanceEndpointAddress: "db-arn",
      port: 5432,
      securityGroups: [],
});

[zilahir]

@romor not really :) the question was whether it's possible to get an RDS instance by it's arn. The example you provided, even you are not doing that, the instanceEndpointAddress is not takes an arn, it takes an url. So this is still a desired feature request.

[rverton]

Also looking for a solution to this, as @zilahir already mentioned, fromDatabaseInstanceAttributes solves a different purpose in my understanding, because you need to pass all attributes manually. @nija-at can you reopen this?

[gshpychka]

The L2 construct needs more information than the ARN to function, so you cannot only reference it by ARN.

To be clear - this function does not do a lookup or any API call, it is just a read-only reference to some resources, so you need to provide all the information it needs to it.

[JoshMcCullough]

I think what we're looking for here is "simply" a way to not have to provide all of these seemingly extraneous details (instanceEndpointAddress, port, securityGroups). I'm sure it's more complicated than I/we realize, but the ask is for a lookup function where we can pass the instanceIdentifier (and nothing else ... maybe region).

[gshpychka]

I think what we're looking for here is "simply" a way to not have to provide all of these seemingly extraneous details (instanceEndpointAddress, port, securityGroups).

Since this is not a lookup (as mentioned above, it does not perform any API calls), it needs all information required by the methods/props that IDatabaseInstance provides.

What you're asking for is a "lookup", which is reasonable, but doesn't exist at all for RDS yet - I would open a new feature request for a lookup function for RDS instances.

[JoshMcCullough]

Yes, asking for a lookup -- exactly.

Submitted a new feature request, thanks!