Add Hashicorp Vault Terraform demo

[bobbyiliev]

Adding an example demo on how to use the Materialize terraform provider alongside the Vault provider.

[morsapaes]

It's so cool to see this work! Thanks for working on it, @bobbyiliev. Left some suggestions, mostly around style and language.

[morsapaes]

It's so cool to see this work! Thanks for working on it, @bobbyiliev. Left some suggestions, mostly around style and language.

[dehume]

I found this a little confusing since VAULT_ADDR is not used anywhere within the Terraform setup. Should we assume they already know how to sue Vault and have a secret?

[bobbyiliev]

This is just to make sure that they create the secret in the locally running vault rather than their production one. The Vault address is defined on line 83.

Open to suggestions if we should remove the Interacting with Vault section cc @morsapaes

[morsapaes]

Maybe the guide should assume users have a Vault in place that they want to read secrets from? This could also make it easier to include examples for multiple external stores using different providers in the same "demo".

[bobbyiliev]

If we decide to do that, I can go ahead and close this PR as it is mainly focused on HashiCorp vault and it would be easier to start from scratch and build a more agnostic guide,

[morsapaes]

Let's not do that! We can make it agnostic when (or if) we add another example.

[bobbyiliev]

I've put together a list of some of the vaults that we might want to include besides HashiCorp Vault and also have official Terraform providers:

• AWS Secrets Manager: Terraform docs
• Azure Key Vault: Terraform docs
• Google Cloud Secret Manager: Terraform docs

Not sure if we want to include these, but they also have Terraform providers:

• 1Password: Terraform docs
• Akeyless Vault: Terraform docs

It should be straightforward to build such a guide as it will essentially be just a reference to each specific provider docs and on the Materialize side, it is just a single secret resource.

Any other suggestions are also welcome!

[dehume]

Should these be var as well to note what configurations would be user specific?

[bobbyiliev]

Not sure if this will be useful for this specific example, the user might not have a Postgres instance on hand?