Environment variables in CDK construct

Issue Summary

I struggle to pass CDK values into the builder for Next to use them as environment variables.

Actual behavior

Values come across as CDK tokens:

env: {
  REGION: '${Token[AWS.Region.6]}'
}

Expected behavior

CDK values to be resolved and embedded into Next env correctly.

Steps to reproduce

Pass values from other CDK constructs (e.g. Function ARN or region) around as props and then pass them to the Builder env options.

Additional Context

I’ve read the discussion in https://github.com/serverless-nextjs/serverless-next.js/issues/184, but it seems not applicable to the CDK construct. It seems a CDK specific issue.

Checklist

• You have reviewed the README and FAQs, which answers several common questions.
• You have reviewed our DEBUGGING wiki and have tried your best to include complete information and reproduction steps (including your configuration) as is possible. As there is only one maintainer (who maintains this in his free time) and thus very limited resources, if you have time, please try to debug the issue a bit yourself if possible.
• You have first tried using the most recent latest or alpha @sls-next/serverless-component release version, which may have already fixed your issue or implemented the feature you are trying to use. Note that the old serverless-next.js component and the serverless-next.js plugin are deprecated and no longer maintained.

[sladg]

It does not work for Lambda@Edge as env variables are not supported. Soooo slsNext.defaultNextLambda.addEnvironment is not gonna cut it.

For now, what works for me is going for printenv > .env during build time. This sets processEnv vars in output/api-lambda/pages/*.

Downside it’s populated for all functions, so in theory, it might be accessible from outside the API, possibly revealing secrets (have not figure out how to pen test it tho).

Hope it helps.

PS. I’m kinda getting pissed at this Edge limitations and deployment speeds. It really feels like having normal Lambda would be easier to grasp.

[musou1500]

@shishkin

NextJSLambdaEdge has some member variables that holds lambda function construct. https://github.com/serverless-nextjs/serverless-next.js/blob/master/packages/serverless-components/nextjs-cdk-construct/src/index.ts#L56-L60

so, for example…

const slsNext = new NextJSLambdaEdge(this, "NextJsApp", {
  serverlessBuildOutDir: "./build"
});
slsNext.defaultNextLambda.addEnvironment("ENV_VAR_KEY", "ENV_VAR_VALUE");