v0.4.0 – rewrite: use Config and Secret Stores, enable local development

[doramatadora]

Starter kit rewrite

This PR:

1. Moves all OAuth configuration to Config Store (OIDC discovery metadata, JWKs, others) and Secret Store (client ID and other secrets). This addresses need to redeploy regularly every few months, it seems the key ids change in jwks.json #18
2. Introduces fastly.toml setup configuration in order to remove the need for setup.sh.
3. Introduces fastly.toml local server configuration in order to enable out-of-the-box local development, pre-configured for Google OAuth clients.
4. Removes an obsolete dependency: toml; supersedes Bump toml from 0.5.11 to 0.8.13 #30.
5. Removes local configuration files.
6. Updates all dependencies to their latest versions; supersedes Bump serde_json from 1.0.117 to 1.0.119 #38, Bump jwt-simple from 0.11.9 to 0.12.9 #37.
7. Improves the README.
8. Updates the CI workflow.

[harmony7]

This is well written and easy to understand.
I have a couple of questions/comments about it, but in general I think it looks good!

My main complaint about this PR is that you called it a "refactor"; to me what you made here counts more as a next version or a rewrite. =)

refactor: To rewrite existing source code in order to improve its readability, reusability or structure without affecting its meaning or behaviour.

[harmony7]

I wonder if you can do something like you do with the redirect_uri (check fastly service version) so that you don't have to modify the code before deploying prod?

[doramatadora]

Great suggestion, thank you!

[harmony7]

You need to mention that the COOKIE_PREFIX needs to be changed between local and production. Or, modify the code that uses the cookie prefix to automatically use the right prefix, see my comment in cookies.rs.

[doramatadora]

I've modified the code so that it automatically uses the right prefix :)