[RFC 0075] Add additional inputs for stack and registry validation

[jabrown85]

RFC 0075
buildpacks/rfcs#135

This RFC is being split into 2 distinct efforts. The first part is described here. Primarily, the first iteration moved around the phases and moved relevant arguments from restorer to analyzer.

This issue will track the remaining work.

The features described in the RFC not yet spec'd are

• Stack validation, to ensure that a new run-image is compatible with the previous app image
• Retrieve identifier (imageID or digest), stack ID, and mixins, which will be used by subsequent phases
• Validation of registry credentials, to avoid a long build that fails during export phase

Analyzer will need to need accept new inputs in order to build those features.

• cache-dir
• run-image
• stack-id
• stack

The spec update should describe what exactly these features mean, if the flags are optional, defaults, new error codes for new failure paths, etc. The RFC is light on those type of details, which is 👌

I think the spec will also need to likely update what analzyed.toml looks like. We will want to be able to store information about the stack so subsequent phases like detector can leverage that information to make decisions.

[natalieparellano]

I think cache-image is also needed?

[jabrown85]

I think cache-image is also needed?

cache-image is already available today and used to resolve the default keychain

[jabrown85]

You are correct @natalieparellano - cache-image was removed from analyzer in the first spec-pr

[natalieparellano]

Closing as implemented in Platform 0.7