allow setting token via environment variable for spin cloud deploy

[rajatjindal]

it will be useful to support setting an env variable which can be consumed by spin cloud deploy to do the deployment.

[vdice]

Can you elaborate on the use case @rajatjindal? Perhaps for scenarios where the spin cloud login action to Fermyon Cloud has been done separate from the current environment (i.e. the json config wouldn't be present locally at spin cloud deploy time?)

Question on precedence: If the env var is non-empty, I'm assuming its value should take precedence over the token stored in the json config, if exists, for the current deployment environment?

[rajatjindal]

Can you elaborate on the use case @rajatjindal? Perhaps for scenarios where the spin cloud login action to Fermyon Cloud has been done separate from the current environment (i.e. the json config wouldn't be present locally at spin cloud deploy time?)

yes, precisely that. if we have a cloud token, we should be able to use that directly without having to write it to a file in a specific format.

Question on precedence: If the env var is non-empty, I'm assuming its value should take precedence over the token stored in the json config, if exists, for the current deployment environment?

yes, I would think so too.

on the other hand, if we want to introduce a flag --token instead of environment variable, that works too.

[lann]

You'd need an env var for server URL (and arguably "danger_accept_invalid_certs") too, wouldn't you? I wonder if we'd be better off adding a --token opt to spin cloud login to update the credentials file.

[endocrimes]

I'd be a big proponent of adding env vars over requiring we write config to a fixed file - esp for CI/CD Workflows where you probably wanna pull those from "some" kind of secret store