[New feature] Add distroinfo feature to update tags or buildsys-tags

[amoralej]

In RDO we have several CI jobs which update rdoinfo yaml files automatically and propose reviews in different cases, as:

• Every night we compare version in : tags: : source-branch to what is in upper-constraints.txt. If a package has been bumped in upper-constraints, we update it in rdoinfo yaml file. [1]
• Every night we check for new builds in CBS which are not tagged in -testing or -release release tags. If some packages are missing, we update : buildsys-tags: in yaml files [2].
• When a review is merged in upstream openstack/requirements project we propose to bump dependencies in RDO by proposing a review to update it in deps.yml file [3]

My proposal is to implement methods in distroinfo to update yaml files. It'd be something like that could be reused in scripts and even rdopkg if needed. Something like:

update_tag('novaclient', 'tags', 'stein-uc', { 'source-branch': '11.0.0' })
or
update_tag('nova', 'buildsys-tags', 'cloud7-openstack-rocky-release', 'python-novaclient-11.0.0-1.el7')

Note, that this call should look for the right file where this info must be stored (or passed as parameter, we can discuss it) and update it.

[1] https://github.com/redhat-openstack/rdoinfo/blob/master/update-uc.py
[2] https://review.rdoproject.org/r/gitweb?p=gating_scripts.git;a=blob;f=buildsys-tags/update-buildsys-tags.py;h=5d065f87b54482a1afb98a7e54d830a753f28739;hb=refs/heads/master
[3] https://review.rdoproject.org/r/gitweb?p=gating_scripts.git;a=blob;f=buildsys-tags/add-buildsys-tags.py;h=18478b6c462200099fcd7ae088a0d5678a0f6254;hb=refs/heads/master

[javierpena]

One implementation detail we should care about: for some packages, we rely on tags assigned by the conf: value, so there is no "stein: stein-uc: ... block".

If we then want to add a tag to such package, we should expand those tags in the package entry.

For example, https://github.com/redhat-openstack/rdoinfo/blob/master/rdo.yml#L604-L616 has no tags, so it we wanted to pin it for stein-uc we would need to create the whole block.