Pulumi

In Pulumi resources have inputs and outputs. Inputs are fairly obvious but Outputs have some interesting characteristics that are worth taking a closer look at. Outputs are effectively promises to resolve to a value once a resource is created. Outputs can in turn be used as inputs to a different resource which has the nice side-effect of establishing ordering/dependencies. When using Pulumi with Go you’ll see that resource structs have a $TypeOutput for most of their fields, like StringOutput.

A component resource is essentially a bundling of a number of resources. For example, when I want to provision a server I also need to assign it IPv4 and IPv6 addresses. I can do this independently, or I can create a custom Server component that does these things for me. This lets me encapsulate the way I work with infrastructure in my code and I can test the behaviour of a component.

For a few years now I’ve had my eyes on Pulumi. Every time I looked at it I came away with a sentiment of “hmm, that seems nice”. I never got around to using it though and nobody around me had either so it was hard to get a sense of whether it would live up to my hopes. I recently decided to redo some of my personal infrastructure and since Pulumi has Hetzner Cloud support I decided to give it a go and see what would happen.