Output only root components

[frigus02]

In our repository we always want to deploy full application stacks. A stack usually consists of multiple APIs and one frontend. The repository contains multiple stacks.

Sometimes a commit contains changes to multiple components and affects multiple stacks. In these cases I want to manually decide which stacks should get deployed. For this I want to ask monobuild for a list of stacks, which changed in this commit.

We should be able to identify stacks in the graph because they don't have any incoming dependencies.

Example:

• Given these components

  api1: lib1, lib2
  api2: lib2
  api3: lib2
  app1: api1, api2
  app2: api3

• And given that lib2 changed in the last commit

• Running monobuild diff --only-components-without-incoming-dependencies could output:

  app1
  app2

[charypar]

I'm thinking --entrypoints or --top-level for the flag. It seems to apply to both diff and print.