How to ensure consistent pulumi environments across developer machines and avoid diffs

[domjancik]

Hi, we're running a fairly large TypeScript based pulumi project using AWS which can take around 40 minutes to deploy from scratch.

We're planning to split it up into microstacks for better control but one thing we also keep running into is deployment diffs even when underlying source code does not change. We see this happen especially when a single dev environment is deployed to from different machines.

We have set up deployments from docker environments in the cloud which are more consistent but direct deployments from developer machines can be the fastest option when testing small incremental changes. We could also set up deployments from docker locally but would prefer to avoid the resource overhead.

When trying to understand what causes the pulumi diffs, we've discovered that the auto-generated mac .DS_Store files are likely part of the problem but clearing those does not fully resolve the inconsistencies. We've also ensured to match up the pulumi and library versions.

Which file properties are considered when doing the code diffs in pulumi? Are file permissions included? Where is the code responsible for it?

What are the best practices for achieving consistent builds and deployments that always only deploy what is really new?