If you are using the s3-deployment module to deploy your website as well, I was able to hack together a solution using what is available currently (pending a better solution at https://github.com/aws/aws-cdk/issues/12903). The following together allow for you to deploy a config.js to your bucket (containing attributes from your stack that will only be populated at deploy time) that you can then depend on elsewhere in your code at runtime.
In inline-source.ts:
// imports removed for brevity
export function inlineSource(path: string, content: string, options?: AssetOptions): ISource {
return {
bind: (scope: Construct, context?: DeploymentSourceContext): SourceConfig => {
if (!context) {
throw new Error('To use a inlineSource, context must be provided');
}
// Find available ID
let id = 1;
while (scope.node.tryFindChild(`InlineSource${id}`)) {
id++;
}
const bucket = new Bucket(scope, `InlineSource${id}StagingBucket`, {
removalPolicy: RemovalPolicy.DESTROY
});
const fn = new Function(scope, `InlineSource${id}Lambda`, {
runtime: Runtime.NODEJS_12_X,
handler: 'index.handler',
code: Code.fromAsset('./inline-lambda')
});
bucket.grantReadWrite(fn);
const myProvider = new Provider(scope, `InlineSource${id}Provider`, {
onEventHandler: fn,
logRetention: RetentionDays.ONE_DAY // default is INFINITE
});
const resource = new CustomResource(scope, `InlineSource${id}CustomResource`, { serviceToken: myProvider.serviceToken, properties: { bucket: bucket.bucketName, path, content } });
context.handlerRole.node.addDependency(resource); // Sets the s3 deployment to depend on the deployed file
bucket.grantRead(context.handlerRole);
return {
bucket: bucket,
zipObjectKey: 'index.zip'
};
},
};
}
In inline-lambda/index.js (also requires archiver installed into inline-lambda/node_modules):
const aws = require('aws-sdk');
const s3 = new aws.S3({ apiVersion: '2006-03-01' });
const fs = require('fs');
var archive = require('archiver')('zip');
exports.handler = async function(event, ctx) {
await new Promise(resolve => fs.unlink('/tmp/index.zip', resolve));
const output = fs.createWriteStream('/tmp/index.zip');
const closed = new Promise((resolve, reject) => {
output.on('close', resolve);
output.on('error', reject);
});
archive.pipe(output);
archive.append(event.ResourceProperties.content, { name: event.ResourceProperties.path });
archive.finalize();
await closed;
await s3.upload({Bucket: event.ResourceProperties.bucket, Key: 'index.zip', Body: fs.createReadStream('/tmp/index.zip')}).promise();
return;
}
In your construct, use inlineSource:
export class TestConstruct extends Construct {
constructor(scope: Construct, id: string, props: any) {
// set up other resources
const source = inlineSource('config.js', `exports.config = { apiEndpoint: '${ api.attrApiEndpoint }' }`);
// use in BucketDeployment
}
}
You can move inline-lambda elsewhere but it needs to be able to be bundled as an asset for the lambda.
This works by creating a custom resource that depends on your other resources in the stack (thereby allowing for the attributes to be resolved) that writes your file into a zip that is then stored into a bucket, which is then picked up and unzipped into your deployment/destination bucket. Pretty complicated but gets the job done with what is currently available.
