RFE - determine build batches from modulemd

[FrostyX]

I imagine that every build system that supports building modules needs to have some piece of code determining what module RPMs can be built simultaneously and which need to wait and be built after some prerequisites. At this moment it is (AFAIK) trivially determined by buildorder.

The problem is, that build systems still need to parse the modulemd (i.e. directly depend on python3-libmodulemd) and implement this basic functionality by themselves. Therefore I think, that modulemd-tools is the right place to put such code.

I am suggesting to create a script called modulemd-builds or more explicitly modulemd-build-batches that will parse a modulemd YAML file and return output in this format.

[
  [
    {
      "name": "jss",
      "repository": "http://foo.bar/jss.git",
      "ref": "master"
    }
  ],
  [
    {
      "name": "tomcatjss",
      "repository": "http://foo.bar/tomcat.git",
      "ref": "master"
    },
    {
      "name": "ldapjdk",
      "repository": "http://foo.bar/ldapjdk.git",
      "ref": "master"
    }
  ],
  [
    {
      "name": "pki-core",
      "repository": "http://foo.bar/pki-core.git",
      "ref": "master"
    },
    {
      "name": "dogtag-pki",
      "repository": "http://foo.bar/dogtag-pki.git",
      "ref": "master"
    }
  ]
]

So, the format it JSON having a list of batches where each batch is represented by a list of packages. The batches need to be built after each other if and only if all the builds from the previous batch succeeded. Packages within a batch can be submitted in random order or in parallel. Each package is represented by a dictionary of all the parameters required for building it.

Do you think it is worth it having such script? Do you like the output format?