Hey guys, anybody know how I can access configuration variables at build-time, say, for instantiating a singleton object? I think I’m able to access configuration variables now from my code, at RT, but it’s not obvious to me how to do so for build-time… Usually, it just works and I don’t ever have to think about this distinction, but with Pulumi, it seems more complicated, when it comes to what I normally just call environment variables in programming. I already got some help on the basics, but again I’m stuck on configurations.

What is the difference between build time and run time here?

I’m trying to do this:

const dynamodb = new DynamoDBClient({
  region: DYNAMODB_REGION || '',
});

but I’m getting this error:

Diagnostics:
  pulumi:pulumi:Stack (content-updater-prod):
    error: Running program '/Users/riyad/repos/content-updater' failed with an unhandled exception:
    Error: Region is missing
        at resolveRegionConfig (/Users/riyad/repos/content-updater/node_modules/@dr-squatch/lib/node_modules/@aws-sdk/config-resolver/dist-cjs/regionConfig/resolveRegionConfig.js:9:15)
        at new DynamoDBClient (/Users/riyad/repos/content-updater/node_modules/@dr-squatch/lib/node_modules/@aws-sdk/client-dynamodb/dist-cjs/DynamoDBClient.js:22:69)
        at Object.<anonymous> (/Users/riyad/repos/content-updater/node_modules/@dr-squatch/lib/dist/aws/dynamodb.js:8:20)
        at Module._compile (node:internal/modules/cjs/loader:1101:14)
        at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
        at Module.load (node:internal/modules/cjs/loader:981:32)
        at Function.Module._load (node:internal/modules/cjs/loader:822:12)
        at Module.require (node:internal/modules/cjs/loader:1005:19)
        at require (node:internal/modules/cjs/helpers:102:18)
        at Object.<anonymous> (/Users/riyad/repos/content-updater/node_modules/@dr-squatch/lib/dist/aws/index.js:4:18)

… maybe I’m confused… maybe it is RT. Just trying to be able to instantiate my dynamodb instance, and possibly other things, using my environment variables / configurations.

Is this AWS region? You can get it from your Pulumi config:

const awsConfig = new pulumi.Config("aws");
const region = awsConfig.require("region");

That is the same region for me for Dynamodb, but it’s possible that I could use a different region for Dynamodb than for AWS in general, isn’t it?

No. If you need to put DynamoDB in a different region, you would need a different provider. You can create two providers in your Pulumi program of course. In which case, the region you want is whichever one you passed to the provider that you created your DynamoDb instance with.

I’m confused… so right now, I have this configuration… I don’t get how to get my code

const dynamodb = new DynamoDBClient({
  region: DYNAMODB_REGION || '',
});

to work (esp from my npm installed dependency @dr-squatch/lib — which is currently private)… I also can’t comment out my dynamodb instantiation in my helper library, as I have other services (via Serverless Framework) successfully consuming that. If I move everything to devDependencies, my eslint complains, though I don’t exactly understand how that might work/help.

Put your DynamoDB region in your Pulumi.stackName.yaml file, as described here: https://www.pulumi.com/docs/intro/concepts/config/ There will be one of these files for each stack (e.g. dev, staging, europe, etc...), and each can have a different value for each config key. Then use the code I posed above to get the configuration value. It will return the value from the file that corresponds to your current stack.

Right now I’m doing this in the codebase to attempt to hook the configurations from Pulumi into my service as regular environment variables.

import * as aws from '@pulumi/aws';
import * as pulumi from '@pulumi/pulumi';
import contentUpdater from './useCases';

const serviceName = 'content-updater';
const config = new pulumi.Config();
const envVars = config.requireObject('env');

const lambda = new aws.lambda.CallbackFunction(`${serviceName}-lambda`, {
  policies: [aws.iam.ManagedPolicies.CloudWatchLogsFullAccess],
  environment: {
    variables: {
      ...envVars as any,
    },
  },
  callback: contentUpdater,
});

I must be missing something simple here? I thought I had this working earlier, but potentially I suppose it’s possible that I may have modified something since then.

Do you have the

myproject:env:

key in your stack file? Is it an array?

I just deleted the other env vars from my file, but my file generally looks like this

I see that env is defined as an object with key:value pairs. Maybe it should be an array? Not sure....

That shouldn’t make a difference, as it’s the types in typescript… Those types are ignored at RT… type-casting in typescript is syntactic sugar at RT, practically speaking. I haven’t looked much further into it since, but tomorrow I might just convert this service to use Serverless Framework if I can’t get this Pulumi configuration stuff hooked up to my environment variables properly.

I know, I just wondered if the object might be a completely different shape to what you're expecting. Can you inspect / introspect it to make sure it's correct? If one thing is expecting an array and the other is an object with multiple key pairs, then it won't work.

hm well I just ran it still doesn’t work, but I just ran it without the { …envVars as any }, as I realized that was just unnecessarily making a new object.

const lambda = new aws.lambda.CallbackFunction(`${serviceName}-lambda`, {
  policies: [aws.iam.ManagedPolicies.CloudWatchLogsFullAccess],
  environment: {
    variables: envVars as any,
  },
  callback: contentUpdater,
});

… I still have the error. What does this screenshot tell us? Is there some other way I’m supposed to be accessing the environment variables? It seems like all the values are there in Pulumi, so I don’t get what happens when I attempt to build the project (which is basically where I was originally today).

I would get

env

then look at it in a debugger / log statements, and compare that to what Function.environment.variables is expecting. FWIW, in our projects that put Pulumi config values into lambda environments, we have this code. Don't know if it's needed, but I inherited this and didn't bother investigating it for efficiency:

const environmentVariables = new Array<KeyValuePair>();
const configEnvironmentVariables = pulumiConfig.getObject(
  "environmentVariables",
) as Record<string, string>;
Object.entries(configEnvironmentVariables).forEach(([k, v]) => {
  environmentVariables.push({ name: k, value: v.toString() });
});

The

environmentVariables

variable is assigned directly to environment.variables.

Ah

Actually that code is for ECS task definitions. Are lambda env vars set up the same way? I forget...

hm good question

Hmm, no, they don't seem to be. They're a simple object, same as the Pulumi config object...

Yeah, probably, based on my IDE docs.

Anywhere after they're instantiated. You need to do it inside an apply though.

myResource.apply((res) => <http://pulumi.log.info|pulumi.log.info>("My resource:", res));